12,736 results on '"Polyols"'
Search Results
2. Soy-based polyester: Sustainable solutions for emerging materials
- Author
-
Chaudhary, Mayankkumar L., Patel, Rutu, Parekh, Sonu, Chaudhari, Sujal, and Gupta, Ram K.
- Subjects
Polymer industry ,Phthalates ,Soybean ,Polymers ,Polyols ,Natural resources ,Engineering and manufacturing industries ,Science and technology - Abstract
Innovative and renewable polymers and additives are the focus of increased research due to public and environmental pressure. There has been a recent uptick in interest from scientists in biobased 'green' plasticizers that can be covalently bonded to replace harmful and migratory phthalate-based plasticizers. Vegetable oils (VOs) are one of the biosources, as they are both plentiful and sustainable. This review aims to highlight the synthesis methods for soy-based polyesters. Therefore, the chemistry of soybean oil as a polymeric material and its role in the synthesis of polyesters derived from soybeans are the primary topics of this review. This review covers the many ways in which soybean oil and its derivatives can be used to synthesize polyester, either directly or indirectly. Highlights * The need for sustainable polymers is explored. * Soybean oil-based polyesters are covered. * Modification and chemistry to convert soybean oil into polyester are described. * Applications of soybean-based polyesters are provided. KEYWORDS biopolymers, polyesters, soybean oil, sustainable polymers, synthesis, 1 I INTRODUCTION At the current pace of usage, fossil fuels will be used up by 2050. (1,2) This is why the use of bio-based feedstock is gaining popularity in [...]
- Published
- 2024
- Full Text
- View/download PDF
3. Unique features of plasticizer-free soft TPU made with bio-based polyol from 3-methyl-1,5-pentanediol and sebacic acid
- Author
-
Okura, Shun, Mayahara, Kunio, Tran, Hoan, and Kuraray
- Subjects
Isocyanates ,Raw materials ,Polyols ,Business ,Chemicals, plastics and rubber industries - Abstract
Thermoplastic polyurethane (TPU) is a multiblock copolymer that consists of a hard segment (HS) with short diols and diisocyanates and a soft segment (SS) with polyols and di-isocyanates. Each segment [...]
- Published
- 2024
4. Fabrication and Characterization of Biopolymers Using Polyvinyl Alcohol and Cardanol-Based Polyols.
- Author
-
Lee, Da Hae, Song, Yun Ha, Ahn, Hee Ju, Lee, Jaekyoung, and Woo, Hee Chul
- Subjects
- *
POLYVINYL alcohol , *BIODEGRADABLE materials , *BIOPOLYMERS , *X-ray diffraction , *PACKAGING materials , *CROSSLINKED polymers , *BIODEGRADABLE plastics , *POLYOLS - Abstract
Biodegradable polymers are getting attention as renewable alternatives to petroleum-based plastics due to their environmental benefits. However, improving their physical properties remains challenging. In this work, biodegradable biopolymers (PVA-PCD) were fabricated by chemically crosslinking petroleum-based polyvinyl alcohol (PVA) with biomass-derived cardanol-based polyols (PCD). Biopolymers were characterized using various techniques, including Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and swelling tests. Cardanol, the raw material, was converted into polyols via epoxidation followed by hydroxylation. FT-IR analysis confirmed that PVA-PCD biopolymers were crosslinked between the hydroxyl groups of PVA and PCD and the aldehydes of crosslinker glutaraldehyde (GLU), accompanied by the formation of acetal groups with ether bridges. XRD showed that the crystallinity of crosslinked polymers decreased, indicating that crosslinking occurs disorderly. TGA exhibited that GLU significantly improved the thermal stabilities of PVA and PCD-PVA polymers, as evidenced by increased decomposition temperatures. On the other hand, the effect of PVA/PCD ratios was minor on biopolymers' thermal stabilities. Swelling tests revealed that increased crosslinking density decreased the swelling ratio, suggesting that PVA-PCD biopolymers become more hydrophobic with high brittleness, high strength, and low swelling capacity. In summary, this study demonstrates that PVA-PCD biopolymers fabricated from biomass-derived materials have potential for various applications, such as biodegradable materials and sustainable packaging. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Pt-N catalytic centres concisely enhance interfacial charge transfer in amines functionalized Pt@MOFs for selective conversion of CO2 to CH4.
- Author
-
Zahid, Muhammad, Ismail, Ahmed, Ullah, Rizwan, Ali, Usman, Raziq, Fazal, Alrebdi, Tahani A., Alodhayb, Abdullah N., Ali, Sharafat, and Qiao, Liang
- Subjects
- *
CHARGE transfer , *POLYOLS , *METAL-organic frameworks , *METAL catalysts , *METHANE , *CARBON dioxide - Abstract
[Display omitted] Improving ligand-to-active metal charge transfer (LAMCT) by finely tuning the organic ligand is a decisive strategy to enhance charge transfer in metal organic frameworks (MOFs)-based catalysts. However, in most MOFs loaded with active metal catalysts, electron transmission encounters massive obstacle at the interface between the two constituents owing to poor LAMCT. Herein, amines (–NH 2) functionalized MOFs (NH 2 -MIL-101(Cr)) encapsulated active metal Pt nanoclusters (NCs) catalysts are synthesized by the polyol reduction method and utilized for the photoreduction of CO 2. Surprisingly, the introduction of –NH 2 (electron donating) groups within the matrix of MIL-101(Cr) improved the electron migration through the LAMCT process, fostering a synergistic interaction with Pt. The combined experimental analysis exposed the high number of metallic Pt (Pt0) in Pt@NH 2 -MIL-101(Cr) catalyst through seamless electron shuttling from N of –NH 2 group to excited Pt generating versatile hybrid Pt-N catalytic centres. Consequently, these versatile hybrid catalytic centres act as electro-nucleophilic centres, which enable the efficient and selective conversion of C O bond in CO 2 to harvest CH 4 (131.0 µmol.g−1) and maintain excellent stability and selectivity for consecutive five rounds, superior to Pt@MIL-101(Cr) and most reported catalysts. Our study verified that the precise tuning of organic ligands in MOFs immensely improves the surface-active centres, electron migration, and catalytic selectivity of the excited Pt NCs catalysts encaged inside MOFs through an improved LAMCT pathway. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Effect of polyol bonding agent on the mechanical properties of hydroxyl‐terminated block copolyether based composite propellant with low aluminum content.
- Author
-
Yang, Wu, Liu, Wenhao, Zheng, Mengze, Zhu, Cong, Li, Tianqi, and Luo, Yunjun
- Subjects
PHOTOELECTRON spectroscopy ,SCANNING electron microscopes ,AMMONIUM perchlorate ,TENSILE strength ,PROPELLANTS ,POLYOLS ,CYCLONITE - Abstract
A polyol bonding agent (BA) was utilized to enhance the mechanical properties of propellant with low aluminum content. Through scanning electron microscope (SEM) and X‐ray photoelectron spectroscopy (XPS) analysis, it was discovered that BA can physically bond to the surfaces of ammonium perchlorate (AP) and hexogen (RDX). The results of mechanical testing showed that the use of BA can significantly improve the mechanical properties of propellants. Specifically, as the amount of BA increases, the maximum tensile strength (σm) of the propellant also increases, the fracture elongation (εb) initially increases and then decreases, the "dewetting ratio" continuously decreases, and the creep resistance of the propellant also increases. At a BA content of 0.2%, the σm of the propellant reaches 0.6 MPa, the εb exceeds 50%, and the "dewetting ratio" is less than 1.1. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. Development of ruthenium-based catalysts for ammonia synthesis via polyol reduction method.
- Author
-
Anello, Gaetano, De Luna, Giulia, De Felice, Giulia, Saker, Assia, Di Felice, Luca, and Gallucci, Fausto
- Subjects
- *
CATALYST testing , *CATALYST synthesis , *CATALYTIC activity , *X-ray diffraction , *METALLIC oxides , *POLYOLS , *RUTHENIUM catalysts , *NITROGEN - Abstract
In this work, ruthenium-based catalysts were synthesized via polyol reduction method with different metal oxides as support and caesium as promoter. The samples were characterized through XRD, ICP-OES, nitrogen physisorption and XPS. Then, the catalysts were tested for ammonia synthesis in the range of temperatures 548–673 K and pressures 1–5 MPa. The synthesized catalysts allowed an ammonia production rate approximately four times higher compared with the performances of similar catalytic formulations in literature (tested at same conditions). The best performance were achieved with the Cs–Ru/CeO 2 (1% wt Cs, 5% wt Ru), reaching an ammonia production of nearly 73 mmol h−1∙g cat −1 at 673 K and 5 MPa. As showed by the XPS analysis, the increased Ce3+/Ce4+ ratio led to an enhancement of oxygen vacancies, which favoured the dissociative adsorption of nitrogen, that is the limiting step in the ammonia synthesis reaction. Such high catalytic activity can be ascribed to the beneficial effect of the polyol reduction method for the maximization of the exposure of active sites. [Display omitted] • Ru-catalysts were synthesized via polyol reduction and tested for NH 3 production. • Cs–Ru/CeO 2 enabled a NH 3 production rate of 43 mmol h−1∙g cat −1 at 673 K and 1 MPa. • Increased Ce3+/Ce4+ ratio enhanced oxygen vacancies favouring N 2 adsorption. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. Investigating in vitro anticholinergic potential (anti-AChE and anti-BuChE) of Chaenomeles leaves extracts and its phytochemicals including chlorophylls, carotenoids and minerals.
- Author
-
Turkiewicz, Igor Piotr, Tkacz, Karolina, Nowicka, Paulina, and Wojdyło, Aneta
- Subjects
- *
HIGH performance liquid chromatography , *ORGANIC acids , *ATOMIC absorption spectroscopy , *TRITERPENES , *PHYTOCHEMICALS , *CHLOROPHYLL , *POLYOLS - Abstract
The goal of this work was to evaluate the chemical constitution and health-promoting potential of 12 varieties of Chaenomeles × superba, speciosa and japonica leaves. Carotenoids, chlorophylls, triterpenes, sugars, polyols and acids were analyzed quantitatively and qualitatively using high pressure liquid chromatography (LC) coupled with mass spectrometry (MS), while the mineral profile was determined using atomic absorption spectroscopy (AAS). Moreover, the in vitro anticholinergic potential (inhibition of acetyl-cholinesterase (AChE) and butyryl-cholinesterase (BuChE)) and antioxidant (ABTS, FRAP, ORAC) capacity were evaluated. For the first time in Chaenomeles genotypes 26 carotenoid derivatives and 22 chlorophyll derivatives were identified. Some varieties contained high amounts of carotenoids and chlorophylls (Ch. × superba 'Colour Trail', 'Nicoline', 'Pink Lady', 'Texas Scarlet'), and triterpenes (Ch. speciosa 'Simonii', 'Rubra', and Ch. × superba 'Colour Trail', 'Nicoline') and showed high ORAC antioxidant (Ch. × superba 'Pink Lady' and Ch. speciosa 'Simonii') and anticholinergic (Ch. speciosa species) activity. The studied leaves also contained sugars (3.1 to 16.5 mg/100 g), organic acids (3.9–8.1 g/100 g), and minerals (Ca, Cu, Fe, K, Mg, Mn, Na, and Zn). In conclusion, Chaenomeles leaves show potential as a new source for the production of nutraceuticals, as well as for medical and/or cosmetic purposes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Chemical Transformation of Biomass-Derived Furan Compounds into Polyols.
- Author
-
Gong, Qihang, Luo, Peikai, Li, Jian, Su, Xinluona, and Cheng, Haiyang
- Subjects
- *
CHEMICAL amplification , *RING-opening reactions , *BIMETALLIC catalysts , *BIOMASS chemicals , *FURFURYL alcohol , *FURFURAL , *POLYOLS - Abstract
Polyols such as 1,5-pentadiol, 1,6-hexanediol, and 1,2,6-hexanetriol are crucial chemicals, traditionally derived from non-renewable fossil sources. In the pursuit of sustainable development, exploring renewable and environmentally benign routes for their production becomes imperative. Furfural and 5-hydroxymethylfurfural are C5 and C6 biomass-derived platform molecules, which have potential in the synthesis of various polyols through hydrogenation and hydrogenolysis reactions. Currently, there is an extensive body of literature exploring the transformation of biomass-derived furan compounds. However, a comprehensive review of the transformation of furan compounds to polyols is lacking. We summarized the literature from recent years about the ring-opening reaction involved in converting furan compounds to polyols. This article reviews the research progress on the transformation of furfural, furfuryl alcohol, and 2-methylfuran to 1,2-pentadiol, 1,4-pentadiol, 1,5-pentadiol, and 1,2,5-pentanetriol, as well as the transformation of 5-hydroxymethylfurfural to 1,2-hexanediol, 1,6-hexanediol, and 1,2,6-hexanetriol. The effects of the supported Pd, Pt, Ru, Ni, Cu, Co, and bimetallic catalysts are discussed through examining the synergistic effects of the catalysts and the effects of metal sites, acidic/basic sites, hydrogen spillover, etc. Reaction parameters like temperature, hydrogen pressure, and solvent are considered. The ring opening catalytic reaction of furan rings is summarized, and the catalytic mechanisms of single-metal and bimetallic catalysts and their catalytic processes and reaction conditions are discussed and summarized. It is believed that this review will act as a key reference and inspiration for researchers in this field. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. Solid-State Structures and Properties of Lignin Hydrogenolysis Oil Compounds: Shedding a Unique Light on Lignin Valorization.
- Author
-
Driscoll, Oliver J., Van Hecke, Kristof, Vande Velde, Christophe M. L., Blockhuys, Frank, Rubens, Maarten, Kuwaba, Tatsuhiro, van de Pas, Daniel J., Eevers, Walter, Vendamme, Richard, and Feghali, Elias
- Subjects
- *
MOLECULAR structure , *BLOCK copolymers , *EPOXY resins , *PHENOLIC resins , *POLYOLS , *LIGNINS , *LIGNANS , *LIGNIN structure - Abstract
This article explores the important, and yet often overlooked, solid-state structures of selected bioaromatic compounds commonly found in lignin hydrogenolysis oil, a renewable bio-oil that holds great promise to substitute fossil-based aromatic molecules in a wide range of chemical and material industrial applications. At first, single-crystal X-ray diffraction (SCXRD) was applied to the lignin model compounds, dihydroconiferyl alcohol, propyl guaiacol, and eugenol dimers, in order to elucidate the fundamental molecular interactions present in such small lignin-derived polyols. Then, considering the potential use of these lignin-derived molecules as building blocks for polymer applications, structural analysis was also performed for two chemically modified model compounds, i.e., the methylene-bridging propyl-guaiacol dimer and propyl guaiacol and eugenol glycidyl ethers, which can be used as precursors in phenolic and epoxy resins, respectively, thus providing additional information on how the molecular packing is altered following chemical modifications. In addition to the expected H-bonding interactions, other interactions such as π–π stacking and C–H∙∙∙π were observed. This resulted in unexpected trends in the tendencies towards the crystallization of lignin compounds. This was further explored with the aid of DSC analysis and CLP intermolecular energy calculations, where the relationship between the major interactions observed in all the SCXRD solid-state structures and their physico-chemical properties were evaluated alongside other non-crystallizable lignin model compounds. Beyond lignin model compounds, our findings could also provide important insights into the solid-state structure and the molecular organization of more complex lignin fragments, paving the way to the more efficient design of lignin-based materials with improved properties for industrial applications or improving downstream processing of lignin oils in biorefining processes, such as in enhancing the separation and isolation of specific bioaromatic compounds). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. Synthesis, Structure, and Actual Applications of Double Metal Cyanide Catalysts.
- Author
-
Nifant'ev, Ilya E. and Ivchenko, Pavel V.
- Subjects
- *
ATMOSPHERIC carbon dioxide , *METAL cyanides , *PROPYLENE oxide , *HETEROGENEOUS catalysts , *CHEMICAL industry , *POLYOLS , *RING-opening polymerization - Abstract
Double metal cyanide (DMC) complexes represent a unique family of materials with an open framework structure. The main current application of these complexes in chemical industry is their use as catalysts (DMCCs) of the ring-opening polymerization of propylene oxide (PO), yielding branched polyols, highly demanded in production of polyurethanes and surfactants. The actual problem of chemical fixing carbon dioxide from the atmosphere gave new impetus to the development of DMCCs, which turned out to be effective in oxirane/CO2 copolymerization. In recent years, new types and formulations of DMCCs were created, so that greater understanding of the reaction mechanisms was achieved and new fields of catalytic applications were found. In the present review, we summarized background and actual information about the synthesis, structure, and mechanisms of the action of DMCCs, as well as their application in the development of new materials and fine chemicals. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. Development of Macromolecular Cryoprotectants for Cryopreservation of Cells.
- Author
-
Yuan, Liang, Chen, Binlin, Zhu, Kongying, Ren, Lixia, and Yuan, Xiaoyan
- Subjects
- *
CRYOPRESERVATION of cells , *POLYZWITTERIONS , *EXTRACELLULAR space , *CRYOPROTECTIVE agents , *DIMETHYL sulfoxide , *POLYOLS - Abstract
Cryopreservation is a common way for long‐term storage of therapeutical proteins, erythrocytes, and mammalian cells. For cryoprotection of these biosamples to keep their structural integrity and biological activities, it is essential to incorporate highly efficient cryoprotectants. Currently, permeable small molecular cryoprotectants such as glycerol and dimethyl sulfoxide dominate in cryostorage applications, but they are harmful to cells and human health. As acting in the extracellular space, membrane‐impermeable macromolecular cryoprotectants, which exert remarkable membrane stabilization against cryo‐injury and are easily removed post‐thaw, are promising candidates with biocompatibility and feasibility. Water‐soluble hydroxyl‐containing polymers such as poly(vinyl alcohol) and polyol‐based polymers are potent ice recrystallization inhibitors, while polyampholytes, polyzwitterions, and bio‐inspired (glyco)polypeptides can significantly increase post‐thaw recovery with reduced membrane damages. In this review, the synthetic macromolecular cryoprotectants are systematically summarized based on their synthesis routes, practical utilities, and cryoprotective mechanisms. It provides a valuable insight in development of highly efficient macromolecular cryoprotectants with valid ice recrystallization inhibition activity for highly efficient and safe cryopreservation of cells. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. Shape‐memory thermosets: Tailoring the structure for toughness improvement and scratch healability.
- Author
-
Nguyen, Ly Mai Thi, Truong, Thuy Thu, Nguyen, Ha Tran, Tran, Chau Duc, Le, Diep Ngoc, Doan, Tin Chanh Duc, and Nguyen, Thu
- Subjects
SHAPE memory polymers ,SCANNING electron microscopy ,TENSILE strength ,MICROSCOPY ,POLYURETHANES ,POLYOLS - Abstract
A straightforward but effective approach to fabricate shape‐memory polyurethane thermosets by tailoring the soft phase composition of two‐ and four‐armed polycaprolactone (PCL) polyols is described. As the crystallization of the PCL soft phase has an effect on driving the self‐assembly of H‐bonds, a good balance of tensile performance and thermo‐healability can be achieved by regulating the ratio between PCL‐diol and PCL‐tetrol in the soft phase. The inferior ability of crystallization of the segments near the branching point gives rise to enhancement of the both overall healability and toughness of the network. Healings of punctured holes and cuts are assessed using optical microscopy (OM), field‐emission scanning electron microscopy (FE‐SEM), tensile analysis, and two‐electrode impedence characterization. The obtained network with the best healing behavior has a soft phase composition with the PCL‐diol/PCL‐tetrol molar ratio of 2/1, a tensile toughness of 64 MPa J−1 and a healing efficiency (estimated by recovery of tensile strength) of nearly 80%. Highlights: The composition of the soft phase of polyurethane networks was tailored.Two‐ and four‐armed polycaprolactones were used for the network structure.A good balance between mechanical and healing performance was obtained.Healing of complete cuts showed tensile strength recovery of nearly 80%. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. Polyols induce acute oxidative stress and mortality in Indian malaria vector Anopheles stephensi (Diptera: Culicidae): potential for use as sugar‐cum‐toxin source in toxic sugar baits.
- Author
-
Jeena, Meenakshi, Kumar, Gaurav, Yadav, Chander Prakash, Lata, Suman, Thakur, Yamini, Kaur, Jaspreet, and Pasi, Shweta
- Subjects
ANOPHELES stephensi ,CHEMICAL industry ,XYLITOL ,HATCHABILITY of eggs ,MOSQUITO vectors ,SUGAR alcohols - Abstract
BACKGROUND: Development of insecticide resistance in the major malaria vectors has necessitated the development of novel vector control tools. One such strategy involves the use of toxic sugar baits that targets the sugar‐feeding behaviour of mosquito vectors. In this study, we investigated the potential of polyols, as a toxic food (sugar) source in toxic sugar baits against the malaria vector Anopheles stephensi Liston. We examined the acute toxicity of six polyols, namely, erythritol, glycerol, mannitol, propylene glycol (PG), sorbitol, and xylitol on adult female An. stephensi mosquitoes at two different concentrations – 2% and 10%. We also studied changes in fecundity, egg hatchability and mid‐gut peroxide levels induced by polyol exposure. RESULTS: Among the six polyol compounds tested, PG was most toxic and lethal followed by glycerol and erythritol (P < 0.001) compared to the control (sucrose). PG induced acute mortality at different tested concentrations. In the erythritol‐ and glycerol‐fed groups, a dose‐dependent effect on mortality was observed. Glycerol evidently reduced fecundity and egg‐hatchability in gonotrophic cycles G1 and G2. Sucrose was the preferred food source (48%), followed by erythritol (18%), PG (10%) and glycerol (8%). Ingestion of polyols increased peroxide levels in mosquito guts, which persisted for extended durations ultimately resulting in rapid mortality (P < 0.05). CONCLUSION: The present study highlights the usefulness of sugar polyols for the development of toxic sugar baits with minimal yet effective ingredients. Further research could be focused on field experiments and on the exploration of synergistic effects of different polyols for optimization of field applications. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. Acceptorless Dehydrogenation of Alcohols and Polyols Over Cu‐Based Catalysts Prepared by NaBH4 Reduction.
- Author
-
Reynoso, Alberto José, Djakovitch, Laurent, and Perret, Noémie
- Abstract
For the first time, oxide (TiO2, CeO2, ZnO, Al2O3) supported Cu catalysts, prepared by the aqueous reduction method using sodium borohydride, were employed for the acceptorless dehydrogenation of 2‐octanol and various C4–C8 polyols. The method used to prepare the catalysts enabled the formation of small Cu particles in the range of 14–36 nm, depending on the point of the zero charge of the support. We showed that the conversion increased with Cu surface area, where Cu/TiO2 led to the highest conversion of 2‐octanol (>99.9%). The selectivity depends on the support and conversion. Up to 80% conversion, the selectivity to 2‐octanone was between 83% and 90% when using Cu/TiO2. In this study, we also report for the first time the acceptorless dehydrogenation of 1,3‐butanediol, 2,3‐butanediol, 1,2‐pentanediol, and 1,5‐pentanediol in liquid phase. While metal active sites promoted the dehydrogenation reaction, the presence of acidic and basic sites favored the formation of by‐products, mainly resulting from dehydration reactions, pinacol rearrangements, and aldol and retro‐aldol condensations. In addition to value‐added chemicals, all the reactions also released molecular hydrogen. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. Synthesis and characterization of bio‐based poly(urethane‐urea) nanocomposite coatings employing cellulose nanocrystals incorporated by two different routes.
- Author
-
Herran, Rodrigo, Molinari, Fabricio Nicolás, Cimas, Axel Javier, Karp, Federico, and Amalvy, Javier Ignacio
- Subjects
- *
CELLULOSE nanocrystals , *YOUNG'S modulus , *RHEOLOGY , *LIGHT absorption , *TENSILE strength , *POLYOLS - Abstract
During the last decades, the interest in the development of materials fully or partially biobased has increased. Polyurethanes are extensively used in a wide range of industries because of their versatility. The present work explores the synthesis of partially biobased poly(urethane‐urea) (PUU) composites employing soy‐based polyol (SPO) and cellulose nanocrystals (CNC). The latter were incorporated during the synthesis (in‐situ) or after the synthesis (ex‐situ). The possibility of a technological application as coatings was investigated for the designed materials. Polycaprolactone diol was used as a soft segment due to high functionality of the soy‐based polyol. The physicochemical, thermal and mechanical properties of the prepared matrices were analyzed. Poly(urethane‐urea)s containing up to 20% by weight of biobased polyol showed coating application potentiality. Compared to a polycaprolactone‐based polyurethane, the utilization of the bioprecursor enhanced light absorption in the UV–Vis region. In addition, partially biobased systems showed better mechanical resistance (Young's modulus increased up to 6 times) and hydrophobicity (sweeling decreased from 60 to 8 per cent by weight). Incorporation of cellulose nanocrystals affected primarily the physicochemical and rheological properties of dispersions. Regarding coating properties, nanocrystals utilization complemented the soy‐based polyol improving the performance of the films. Furthermore, the incorporation route affected the dispersions and films properties. Highlights: SPO was incorporated up to 20 per cent by weight in PUU composites.Higher SPO contents improved UV–Vis absorption and tensile strength of films.Films were less hydrophilic as more SPO was incorporated.The CNC‐reinforcement was complementary to the utilization of the SPO.CNC incorporation route affects properties and performance of the coatings. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. Review: Application status of antibacterial polyurethane.
- Author
-
Bo, Cai, Zhijia, Zhang, Wenjun, Zhou, Songsong, Zhang, Guojun, Wang, Qiang, Wang, Teng, Ma, Lin, Wang, and Hao, Wei
- Subjects
- *
BIOMEDICAL materials , *FOOD packaging , *ANTIBACTERIAL agents , *WATER purification , *POLYOLS - Abstract
Polyurethane is a kind of synthetic polymer composed of isocyanates, polyols and chain extenders. Due to its excellent mechanical flexibility, biodegradability and physicochemical properties, polyurethane is widely used in biological, medical, food and antifouling fields. With the continuous development of science and technology, ordinary polyurethane materials have been unable to meet people's diverse and high standard aseptic requirements, and the development and application of antibacterial polyurethane is getting more and more attention. In this paper, the antibacterial modification methods of polyurethane materials were introduced, and the application status and antibacterial mechanism of polyurethane materials in medical treatment, food packaging, water treatment and other aspects in recent years were reviewed. At the end, the problems faced in the application of antibacterial polyurethane materials and corresponding improvement measures are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. Synthesis and characterization of polyHIPEs using a polymerizable polyurethane macromolecular surfactant.
- Author
-
Hou, Xu, Chang, Le, Zheng, Chenxuan, and Liu, Huarong
- Subjects
- *
POLYMERS , *POROUS materials , *BASE oils , *SURFACE active agents , *POLYURETHANES , *POLYOLS , *MACROPOROUS polymers - Abstract
High internal phase emulsions (HIPEs) are commonly stabilized by a large amount of surfactants that should be removed after the polymerization of the continuous phase, and the resulting polyHIPEs from W/O HIPEs are usually brittle and chalky. Herein we report on an amphiphilic polymerizable polyurethane (PPU) macromolecular surfactant synthesized by polyaddition reaction of diisocyanates and polyols, which can well stabilize up to 88% internal phase volume of W/O HIPE with a content of only 5 wt% based the oil phase. Compared with the HIPEs stabilized by traditional surfactant Span 80, HIPEs stabilized by PPU at either room temperature or 70 °C are much more stable owing to the increased viscosity which can inhibit droplet coalescence. Moreover, the resulting polyHIPEs not only have several times higher mechanical properties than those stabilized by Span 80 but also have higher elasticity. The effects of concentration of PPU on the morphology and mechanical properties of the resulting polyHIPEs were investigated. It was found that with the increase of PPU content, the average void and window sizes decreased, while the compression strength increased. Cyclic compression tests were performed to examine reversible compressibility and durability of these polyHIPEs. The polymerizable polyurethane macromolecular surfactant (PPU) synthesized through the polyaddition reaction of diisocyanates and polyols can solely stabilize high internal phase emulsions (HIPEs), and highly interconnected macroporous polymer produced by the polymerization of HIPE stabilized with PPU, known as polyHIPE, can withstand large deformation compression with no visible cracks. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Evaluation of natural oil polyol hydrophobic acrylic-based coating incorporated with SiO2 nanoparticles for enhanced corrosion protection.
- Author
-
Wonnie Ma, Iling Aema, Ong, Gerard, Shafaamri, Ammar, Jamalludin, Julie Nabilah, Ishun, Nina Nazirah, Kasi, Ramesh, and Subramaniam, Ramesh
- Subjects
- *
EPOXY coatings , *POLYOLS , *HYDROPHOBIC surfaces , *COMPOSITE coating , *CONTACT angle , *POLYMERIC composites , *FOURIER transform infrared spectroscopy - Abstract
Purpose: This study aims to fabricate the acrylic-based polymeric composite coating with a hydrophobic surface associated with natural oil polyol (NOP) and polydimethylsiloxane with the incorporation of 3 Wt.% SiO2 nanoparticle (SiO2np) against the corrosive NaCl media. Design/methodology/approach: The structural properties of the formulated polymeric composite coatings were investigated by using Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, water contact angle (WCA) and cross-hatch (X-Hatch) tests. The WCA measurement was used to study the surface wettability of the formulated polymeric composite coatings. The corrosion protection performance of the nanocomposite coated on the mild steel substrate was studied by immersing the samples in 3.5 Wt.% NaCl solution for 30 days using electrochemical impedance spectroscopy. Findings: The enhanced polymeric composite coating system performed with an excellent increase in the WCA up to 111.1° which is good hydrophobic nature and very high coating resistance in the range of 1010 Ω attributed to the superiority of SiO2np. Originality/value: The incorporation of SiO2np into the polymeric coating could enhance the surface roughness and hydrophobic properties that could increase corrosion protection. This approach is a novel attempt of using NOP along with the addition of SiO2np. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. A Comprehensive Review on Biobased Hyperbranched Polymers.
- Author
-
Bhutra, Komal, Datta, Sayan, and More, Aarti P.
- Subjects
- *
BRANCHED polymers , *TANNINS , *POLYMERIC nanocomposites , *SUCCINIC acid , *VEGETABLE oils , *LIGNINS , *POLYOLS - Abstract
Environmental issues, including climate change and plastic pollution, have compelled scientists to look at alternatives to traditional polymers. Scientists are actively researching biobased hyperbranched polymers, an emerging group of highly branched polymers made from sustainable resources. They are seen as a promising alternative to petrochemical-based polymers. Hyperbranched polymers can be made using single- and double-monomer techniques. This review provides an extensive perspective of the synthesis and properties of biobased hyperbranched polymers made from a variety of renewable starting materials, including starch, lignin, vanillin, levulinic acid, furfurylamine, ferulic acid, citric acid, adipic acid, succinic acid, and tannic acid and various vegetable oils have been investigated till date. Most of these biobased hyperbranched polymers have been created using vegetable oil as their raw materials because numerous vegetable oil derivatives like monoglycerides, polyols, and fatty acids can be potentially used as monomers for the polymer. In the paper, specifics about modified biobased hyperbranched polymers, their composites, nanocomposites, and functionalized versions are highlighted. These materials belong to a class that combines the special characteristics of hyperbranched polymers with the reinforcing and functionalizing effects of fillers like silver, carbon, silicone, clay, etc. Lastly, the paper also discusses the various practical applications of biobased hyperbranched polymers in various industrial sectors and their prospects for the future. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. Physico-chemical and Biosafety Evaluations of a Polyurethane Carrier Used for Bevacizumab.
- Author
-
ALBULESCU, RAMONA CARMEN, BORCAN, LIVIA-CRISTINA, and BORCAN, FLORIN
- Subjects
POLYURETHANES ,BEVACIZUMAB ,DRUG delivery systems ,POLYMER structure ,POLYOLS - Abstract
The monoclonal antibody bevacizumab, which neutralizes vascular endothelial growth factor, significantly affects the migration, survival, and proliferation of cells - all of which are critical for the growth and spread of tumors. The current study's objective was to create polyurethane structures that are more soluble in water so they may be employed as this active agent's transmembrane carrier. A polymer drug delivery system was created using an aliphatic isocyanate and a combination of ether and ester polyols, resulting in a suitable release profile and membrane penetrability. The solubility, pH, and refractivity index measurements, the size distribution and surface charge, the encapsulation efficacy and release profile, the proliferation of cells, and skin irritation tests on mice were used to describe the two samples. Our findings reveal that nearly neutral acido-basic polymer structures were achieved, ranging in size from 187 to 423 nm. Zeta potential values suggest a minor alteration in the propensity to form clusters in the sample with increased solubility, and UV-Vis analyses demonstrate an approximately 63±2% encapsulation efficacy. In terms of the samples' biosafety profile, the tests conducted on mouse skin and cell cultures did not result in significant adverse effects at the concentrations that were examined. The results of this preclinical investigation indicate that adding polar groups to polyurethane macromolecular chains improves aqueous solubility without changing the polymer carrier's other properties. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Bio-Based Polyurethane Composites from Macauba Kernel Oil: Part 1, Matrix Synthesis from Glycerol-Based Polyol.
- Author
-
Andrade Breves, Rodolfo, Ajiola, Daniel, de Vasconcelos Vieira Lopes, Roseany, Quirino, Rafael L., Colin, Baptiste, Petrissans, Anelie, Petrissans, Mathieu, and Sales, Maria José Araújo
- Subjects
RING-opening reactions ,URETHANE foam ,POLYURETHANES ,THERMAL stability ,POLYMERS ,POLYOLS - Abstract
Polyurethanes are the result of a reaction between an isocyanate and a polyol. The large variety of possible reagents creates many possible polyurethanes to be made, such as soft foams, rigid foams, coatings, and adhesives. This polymer is one of the most produced and consumed polymers in the world with an ever-increasing demand. Despite its usual petrochemical nature, research on bio-based polyurethanes flourishes due to the ease in creating bio-based polyols. This work covers the synthesis of a novel macauba kernel oil polyol by the epoxidation of the oil, followed by a ring-opening reaction of the epoxide with glycerol, used for the preparation of polyurethane foams using different NCO/OH ratios. The FTIR and H
1 results confirm the formation of the epoxide and polyol, and the polymers in all NCO/OH ratios were confirmed by FTIR, showing great similarities between the samples, especially PU 1.0 and PU 1.2. Despite the TGs showing close behaviors for the three samples, their DTGs showed great difference between the samples, with PU 1.0 presenting a regular PU DTG profile with three degradation peaks while the other two sample presented five degradation peaks, indicating a higher crosslinking density in them. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
23. Towards direct superlubricity and superlow wear via amino modification of polyhydroxy alcohol solutions.
- Author
-
Ma, Qiang, Yan, Chengpeng, Yan, Rui, Xu, Xin, and Wang, Haifeng
- Subjects
POLYOLS ,BOUNDARY lubrication ,MONOMOLECULAR films ,HYDROGEN bonding interactions ,AMINO group ,ELASTOHYDRODYNAMIC lubrication ,HYDROGEN bonding - Abstract
Friction remains as the primary mode of energy dissipation and components wear, and achieving superlubricity shows high promise in energy conservation and lifetime wear protection. The results in this work demonstrate that direct superlubricity combined with superlow wear can be realized for steel/Si
3 N4 contacts on engineering scale when polyhydroxy alcohol solution was selectively modified by amino group. Macroscopic direct superlubricity occurs because 3-amino-1,2-propanediol molecules at the friction interface could be induced to rotate and adsorb vertically on the friction surface, forming in-situ thick and dense molecular films to passivate the asperity contacts. Furthermore, amino modification is also conducive to improving the lubrication state from boundary to mixed lubrication regime by strengthening the intermolecular hydrogen bonding interaction, presenting enhanced load-bearing capability and reduced direct solid asperity contacts. Thus, direct superlow average friction of 0.01 combined with superlow wear are achieved simultaneously. The design principle of direct superlubricity and superlow wear in this work indeed offers an effective strategy to fundamentally improve energy efficiency and provide lifetime wear protection for moving mechanical assemblies. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
24. The role of polyols as plasticisers to extend egg life.
- Author
-
Gabriela da Silva Pires, Paula, Dirceu Pazdiora, Raul, Leuven, Aline Fernanda, da Silva Oliveira, Gabriel, McManus, Concepta, and dos Santos, Vinícius Machado
- Subjects
POLYOLS ,ALBUMINS ,HUMIDITY ,POLYSACCHARIDES ,PLASTICIZERS - Abstract
SUMMARY: In eggs, the albumen and yolk undergo physicochemical changes during storage, which will decrease egg quality. Several factors can contribute to the loss of egg quality (such as temperature, humidity, duration of storage, thin eggshell, age of the flock). Coatings are a tool that can help maintain egg quality during long storage periods. The standard composition of egg coatings includes polysaccharides, lipids, proteins and polyols that can be used as plasticising substances and incorporated to induce flexibility in films. Glycerol is the most commonly used plasticiser in egg coatings due to its abundance and relatively low cost. However, other substances have demonstrated better results when added to coatings to extend the shelf life of eggs. Few studies have investigated the relationship between polyol plasticisers and the different bases for preparing coatings. Furthermore, little discussion exists about which levels should be incorporated into the egg-coating solution. The real impact of using polyols in egg coatings still has some gaps. This review gives an overview of the current use of polyols and trends in developing new egg coatings. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Analyzing the influence of diols' chain length on the properties of bio‐based wood adhesive.
- Author
-
Parekh, Sonu, Chaudhary, Mayankkumar L., Patel, Rutu, Patel, Pratik, and Gupta, Ram K.
- Subjects
METALLIC bonds ,UREA-formaldehyde resins ,SOY oil ,CHEMICAL stability ,BOND strengths ,POLYOLS - Abstract
Traditional adhesives made using urea or phenol formaldehyde are toxic to humans and the environment, and as a result, the industry is very interested in developing bio‐based adhesives. Polyurethane (PU)‐based adhesives are very attractive due to their strong bonding strength, and thermal and chemical stability. Polyols derived from petrochemicals are one of the most important constituents in PU‐based adhesives. Current trends are to find an alternative for petrochemical‐based polyols without compromising the important characteristics of adhesives. In this research, PU adhesives were prepared using soybean oil‐based polyol and isocyanate. Three different diols such as 1,2‐ethanediol (EDO), 1,4‐butanediol (BDO), and 1,6‐hexanediol (HDO) were used to study the effect of crosslinking, amount of crosslinkers (diols), and diol's chain length on the properties of bio‐based adhesives. The adhesive's lap shear strength using metallic and wood coupons was measured. The BDO‐based bio‐adhesives showed the best bonding strength compared to EDO and HDO adhesives. The mechanical strength was observed to be increasing with an increase in the amount of diols up to a certain concentration and then started decreasing. On the oakwood, the bonding strength was increased from 3 to 6.36 MPa after incorporating 10 wt% of BDO which was the highest bonding strength observed among all the other adhesives. The thermal and chemical stability of these adhesives were also studied. Structural characterization confirms no significant changes after being immersed in different solvents for 24 h. This work introduces a sustainable alternative to petroleum‐based adhesives using polyols from vegetable oil. Highlights: Soybean oil‐based polyol was used for adhesives.1,2‐Ethanediol, 1,4‐butanediol, and 1,6‐hexanediol were used as crosslinkers.The bonding strength was measured using wood and metallic coupons.The bonding strength was observed to be increasing with an increase in the amount of diols.The highest bonding strength of 6.36 MPa was observed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Effect of Fatty Acids on Vegetable-Oil-Derived Sustainable Polyurethane Coatings for Controlled-Release Fertilizer.
- Author
-
Pang, Minhui, Liu, Zirui, Li, Hongyan, Liang, Lina, and Li, Lixia
- Subjects
SUSTAINABLE chemistry ,CONTROLLED release of fertilizers ,VEGETABLE oils ,FATTY acids ,DOUBLE bonds ,POLYOLS ,LINSEED oil - Abstract
Vegetable-oil-based polyurethane has become a promising sustainable candidate for controlled-release fertilizer based on green chemistry. The purpose of this study was to prepare a series of coatings from selective feedstocks including five vegetable oils with a high saturation degree, mono-unsaturation degree, or poly-unsaturation degree, considering that vegetable oil fatty acids played a key role in the synthesis of polyol and polyurethane. The effect of the type and proportion of fatty acids on the physicochemical properties, microstructure, and macro-properties of vegetable-oil-derived polyols and their resulting coatings was characterized and discussed. The position and number of the hydroxy groups were determined by the type and proportion of fatty acid, and polyol from linseed oil with a high poly-unsaturation degree and three carbon–carbon double bonds had a high hydroxyl value and functionality, whereas polyol from palm oil with a high saturation degree possessed the lowest hydroxyl value and functionality. The resultant coating from linseed-oil-based polyol had a good cross-linking density, and the nitrogen release longevity of coated urea was 56 days at a coating percentage of 3%, and its nitrogen use efficiency was increased by 27.15% compared with conventional urea. Although the palm-oil-based coating had good hydrophobicity, its coated urea was not ideal. Overall, this study has enriched theories of bio-based polyurethane coatings for controlled-release fertilizers; using vegetable oil with a poly-unsaturation degree, it is easy to obtain an excellent coating for controlled-release fertilizer, and this will help provide economic and environmental benefits. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Development and Characterization of Novel Illumination Pyrotechnic Formulations.
- Author
-
Dîrloman, Florin, Noja, Gabriel-Flavius, Rotariu, Adrian, Rotariu, Traian, Trană, Eugen, Iorga, Ovidiu, and Gîlcă, Narcis
- Subjects
FIREWORKS ,POLYURETHANES ,POLYOLS ,COMBUSTION ,CATALYSTS - Abstract
This paper describes the investigations related to the development and characterization of various illumination pyrotechnic compositions based on polyurethane binders synthesized from commercial isocyanates and polyols, an oxidizer, two types of metallic powder and a burning catalyst. These types of binders improve the processability and minimize the risk associated with the manufacture process. The performance and safety characteristics of the novel pyrotechnic formulations were evaluated through various analytical techniques (DTA) and specific tests (rate of combustion, heat of combustion, specific volume, chemical stability, sensitivity to impact stimuli), according to NATO standards, providing promising preliminary results for further experimental investigations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Polyurethane-polyisocyanurate (PUR-PIR) foams based on castor oil modified with tire rubber waste: Statistical-based analysis
- Author
-
Saboia, Matheus Marciano, da Silva, Andressa Ilidia Calheiros, Monteceli, Francisco Maciel, Sampaio, Nilo Antonio de Souza, da Conceicao, Monique Osorio Talarico, and Mulinari, Daniella Regina
- Subjects
Isocyanates ,Polyurethanes ,Castor oil ,Polyols ,Rubber ,Engineering and manufacturing industries ,Science and technology - Abstract
This study explores the utilization of bio-polyol, derived from castor oil modified with waste tire rubber (WTR), in the synthesis of rigid polyurethane-polyisocyanurate foams. Two WTR concentrations (10% and 20%) were incorporated, investigating their impact on foaming, cellular structure, and various foam properties. Response surface methodology assessed the influence of polyol/isocyanate ratios and WTR content on thermal, physical, and mechanical responses. Results indicated significant effects of polyol/isocyanate ratios on thermal and density properties, while WTR content exhibited an opposite trend. Mechanical behavior showed a distinct pattern compared to thermal and physical aspects, suggesting no conclusive correlation between compressive stress variability and polyol/ isocyanate ratio or WTR content. Consequently, the application of these foams depends on specific property requirements, highlighting the potential of sustainable bio-polyols and recycled WTR in replacing conventional petroleum-based counterparts in polyurethane foam production. Highlights * Development of rigid polyurethane-polyisocyanurate foams based on castor oil. * Polyurethane-polyisocyanurate foams modified with waste tire rubber. * Increased isocyanate index impacts thermal stability and density. * Response surface methodology showed variability in compressive stress behavior and the polyol/isocyanate ratio. * For application of polyurethane-polyisocyanurate foams will depend on the desired properties. KEYWORDS castor oil, response surface methodology, rigid polyurethane-polyisocyanurate foams, tire rubber waste, 1 | INTRODUCTION Improper disposal of solid waste is one of the main environmental problems currently faced. (1) With the increase in population and consumption, the amount of waste generated [...]
- Published
- 2024
- Full Text
- View/download PDF
29. Biodegradable hydroxylase polyols production from epoxidized palm oleic acid.
- Author
-
Azmi, Intan Suhada, Jalil, Mohd Jumain, and Hadi, Abdul
- Abstract
Recently, the trend of using renewable sources has great attention in the production of polyol chemicals via the epoxidation method. Palm-based polyols produced from the epoxidation and hydroxylation methods usually have low hydroxyl values (below 200 mg KOH/g). This study aimed to synthesize the hydroxylase polyols with a higher hydroxyl value from the renewable source palm oil. The epoxidized palm oleic acid was synthesized using the in situ performic acid, which is obtained from the reaction of formic acid and hydrogen peroxide. The Taguchi method was executed to optimize the epoxidation process for the maximum production of epoxidized oleic acid. Then, optimized epoxidized palm oleic acid was hydroxylated to produce polyols. In addition, the effect of process parameters on the polyol yields was also studied. At the optimum process parameters, the response of relative conversion to oxirane (RCO) with the determination of oxirane oxygen content (OOC) was found at the maximum value of 82%. According to the results, the maximum hydroxyl value produced was 339 mg KOH/g. A kinetic study revealed that the oxirane cleavage by methanol is a second-order reaction whereas the formation of epoxidized palm oleic acid is a first-order reaction. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
30. Monitoring Trends in Packaged Food Supply for Added Sugar and Sweeteners: Are We Jumping out of the Frying Pan into the Fire?
- Author
-
Murat Gürbüz, Selinay Demirel, Miray Nur Aykut, Esma Nur Erdoğan, Beyza Balcı, and Gözde Özaslan
- Subjects
food additives ,added sugar ,intense sweeteners ,non-nutritive sweeteners ,polyols ,Agriculture ,Agriculture (General) ,S1-972 - Abstract
Excessive sugar intake can lead to poor health outcomes. The use of sweeteners is considered as a strategy to reduce added sugar consumption. The presence of sweeteners in food products has increased significantly in many countries. Therefore, the aim of this study was to identify the added sugars and sweeteners in packaged products. 1550 (57.9%) out of 2676 food products contained at least one added sugar. Confectionery and desserts (35.38±24.82 g/100 g), and snack foods (20.70±16.20 g/100 g) were the main categories containing the highest amount of added sugar. 229 (8.6%) out of 2676 food products contained various types of sweeteners. The most popular added sugar was sucrose (62.9%), while the most popular sweetener was sorbitol (28.2%). This is the most comprehensive study in the city center of Edirne province in Türkiye reporting on the types and frequency of added sugars and sweeteners in packaged products. This study offers monitoring to improve the legislation of Türkiye on added sugars and sweeteners used in the food supply.
- Published
- 2024
- Full Text
- View/download PDF
31. Diffusion in biological media: a comprehensive numerical-analytical study via surface analysis and diffusivities calculation
- Author
-
Juan Ignacio González Pacheco and Mariela Beatriz Maldonado
- Subjects
Mathematical modelling ,Mass transfer phenomena ,Polyols ,Plant-based dyes ,Diffusion coefficients ,Natural food production ,Medicine ,Science - Abstract
Abstract The study of diffusion in biological materials is crucial for fields like food science, engineering, and pharmaceuticals. Research that combines numerical and analytical methods is needed to better understand diffusive phenomena across various dimensions and under variable boundary conditions within food matrices. This study aims to bridge this gap by examining the diffusion of substances through biological materials analytically and numerically, calculating diffusivity and conducting surface analysis. The research proposes a process for sweetening Bing-type cherries (Prunus avium) using sucrose/xylitol solutions and a staining technique utilising erythrosine and red gardenia at varying concentrations (119, 238 and 357 ppm) and temperatures (40, 50 and 60 °C). Given the fruit's epidermis resistance, the effective diffusivities of skin were inferior to those in flesh. Temperature and concentration synergise in enhancing diffusion coefficients and dye penetration within the food matrix (357 ppm and 60 °C). Red gardenia displayed significant temperature-dependent variation (p = 0.001), whereas erythrosine dye remained stable by temperature changes (p > 0.05). Gardenia's effective diffusivities in cherry flesh and skin, at 357 ppm and 60 °C, 3.89E−08 and 6.61E−09 m2/s, respectively, significantly differed from those obtained at lower temperatures and concentrations. The results highlight the temperature-concentration impacts on mass transfer calculations for food colouring processes and preservation methodologies.
- Published
- 2024
- Full Text
- View/download PDF
32. INOSITOLS: BIOLOGICAL ROLE AND APPLICATION, METHODS OF EXTRACTION FROM PLANT RAW MATERIALS AND DETERMINATION, BIOTECHNOLOGICAL SYNTHESIS
- Author
-
V. A. RAKS, O. A. VASYLCHENKO, O. V. MYRONIUK, A. O. BILOUSOVA, О. M. LYSENKO, and N. V. KURDIL
- Subjects
polyols ,inositols ,extraction ,chromatography ,nmr spectroscopy ,Biotechnology ,TP248.13-248.65 - Abstract
The aim of the work was to review modern extraction, detection and quantification analytical methods of inositols and their derivatives. Methods. Inositols are extracted from vegetable raw materials by methods of liquid extraction, under pressure, microwave extraction and supercritical fluid extraction. Quantitatively analyzed by methods of gas and liquid chromatography with preliminary derivatization. The structure of inositols can be determined by the NMR spectroscopy. Results. Inositols and their derivatives are biologically active compounds, wich are involved in the egulation of the intracellular calcium level, the transmission of hormonal signals, the breakdown of fats and the reduction of cholesterol in the blood, the modulation of the neurotransmitters activity, etc. Inositols are used in the production of vitamin preparations. The main source for inositols extraction is vegetable raw material, namely alfalfa, as well as wheat sprouts, grapefruit, hazelnuts and others. In the paper, the methods of inositols extraction with organic and inorganic solvents, including the use of a Soxhlet apparatus, liquid extraction under pressure, microwave extraction and supercritical fluid extraction are considered. The procedure of preliminary sample preparation and polyols derivatization for their further separation and quantitative determination is described. Modern chromatographic methods of polyols identification and quantitative determination are analyzed. The possibility of using 1H, 13C and 31P NMR spectroscopy to identify the structure of inositols and their derivatives is described. Conclusions. Inositols are biologically active compounds of a wide spectrum of action, therefore there is an urgent need to develop biotechnological processes for their production and extraction from plant raw materials and microorganisms.
- Published
- 2024
- Full Text
- View/download PDF
33. Exploration of Trichoderma reesei as an alternative host for erythritol production
- Author
-
Audrey Masi, Georg Stark, Johanna Pfnier, Robert L. Mach, and Astrid R. Mach-Aigner
- Subjects
Erythritol ,Trichoderma reesei ,Polyols ,Design of experiments ,Biotechnology ,TP248.13-248.65 ,Fuel ,TP315-360 - Abstract
Abstract Background Erythritol, a natural polyol, is a low-calorie sweetener synthesized by a number of microorganisms, such as Moniliella pollinis. Yet, a widespread use of erythritol is limited by high production costs due to the need for cultivation on glucose-rich substrates. This study explores the potential of using Trichoderma reesei as an alternative host for erythritol production, as this saprotrophic fungus can be cultivated on lignocellulosic biomass residues. The objective of this study was to evaluate whether such an alternative host would lead to a more sustainable and economically viable production of erythritol by identifying suitable carbon sources for erythritol biosynthesis, the main parameters influencing erythritol biosynthesis and evaluating the feasibility of scaling up the defined process. Results Our investigation revealed that T. reesei can synthesize erythritol from glucose but not from other carbon sources like xylose and lactose. T. reesei is able to consume erythritol, but it does not in the presence of glucose. Among nitrogen sources, urea and yeast extract were more effective than ammonium and nitrate. A significant impact on erythritol synthesis was observed with variations in pH and temperature. Despite successful shake flask experiments, the transition to bioreactors faced challenges, indicating a need for further scale-up optimization. Conclusions While T. reesei shows potential for erythritol production, reaching a maximum concentration of 1 g/L over an extended period, its productivity could be improved by optimizing the parameters that affect erythritol production. In any case, this research contributes valuable insights into the polyol metabolism of T. reesei, offering potential implications for future research on glycerol or mannitol production. Moreover, it suggests a potential metabolic association between erythritol production and glycolysis over the pentose phosphate pathway.
- Published
- 2024
- Full Text
- View/download PDF
34. Contents list.
- Subjects
- *
INORGANIC chemistry , *COMPUTATIONAL chemistry , *SANDWICH construction (Materials) , *ORGANIC acids , *BIOCHEMISTRY , *METAL complexes , *TRANSITION metal complexes , *POLYOLS , *PROPELLANTS - Abstract
The document is a contents list of the journal "Dalton Transactions: An International Journal of Inorganic Chemistry," which covers various topics related to inorganic chemistry. It includes articles on metal complexes, electrocatalysts, nanocrystals, and organic synthesis. The journal aims to provide original research and perspectives to contribute to scientific progress in the field of chemistry. One article discussed in the document is about the synthesis and characterization of copper complexes that can be used in the degradation of organic dyes using visible light. Another article focuses on the synthesis and characterization of palladium complexes for use in focused electron beam induced deposition. [Extracted from the article]
- Published
- 2024
- Full Text
- View/download PDF
35. Colloidal synthesis of two-dimensional nanocrystals by the polyol route.
- Author
-
Kimberly, Tanner Q., Frasch, Michelle H., and Kauzlarich, Susan M.
- Subjects
- *
BINDING agents , *REDUCING agents , *NANOSTRUCTURED materials , *NANOCRYSTALS , *SURFACE active agents , *POLYOLS - Abstract
The field of 2D nanomaterials is ever-growing with a myriad of synthetic advancements that have been used to obtain such materials. There are top-down, as well as bottom-up, fabrication methods for obtaining 2D nanomaterials; however, synthesis of 2D nanomaterials from solution offers a simple scalable way to control size, shape, and surface. This review outlines the recent advances in colloidal polyol synthesis of 2D nanomaterials and provides perspectives on the similarities and differences in various syntheses. Various materials classes are presented and discussed, including metals, oxides, chalcogenides, and halides, that can be synthesized as 2D nanomaterials via a polyol process. Throughout the literature, polyol media is demonstrated to be versatile not only as a solvent and reducing agent for metal precursors but also as a binding and shape-directing agent for many 2D nanomaterials. Polyols also offer the ability to dissolve various surfactants and additives that can further control the morphology and composition of various nanomaterials. In this review, we outline the various 2D materials that have been realized via the solution polyol route. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. Contents list.
- Subjects
- *
SUSTAINABLE chemistry , *SUSTAINABILITY , *OXYGEN evolution reactions , *SCANDIUM catalysts , *OPEN access publishing , *CONJUGATED polymers , *POLYOLS , *RING-opening reactions - Abstract
The document is a contents list for the journal "Green Chemistry," published by The Royal Society of Chemistry. It highlights the articles and papers featured in the current issue, covering a range of topics related to sustainable chemistry and green technologies. The articles include research on bio-based polymers, nitrogen fixation strategies, carbon aerogels for energy storage, and the use of ionic liquids in new energy and biotechnologies. The journal aims to provide cutting-edge research for a greener and more sustainable future. [Extracted from the article]
- Published
- 2024
- Full Text
- View/download PDF
37. A new scandium based catalyst for the green synthesis of polyols-polyesters starting from waste raw materials.
- Author
-
Losito, Onofrio, Veronico, Lorenzo, De Cataldo, Alessia, Casiello, Michele, Fusco, Caterina, Gentile, Luigi, Mesto, Ernesto, Schingaro, Emanuela, and D'Accolti, Lucia
- Subjects
- *
SCANDIUM catalysts , *MOLECULAR weights , *HETEROGENEOUS catalysts , *3-D printers , *INDUSTRIAL capacity , *POLYOLS - Abstract
Following our previous studies aimed at the valorization of cellulose waste and glycerol, biobased polyols-polyesters were synthesized using both a "green approach" and a novel heterogeneous catalyst based on scandium silicate thortveitite. The latter showed an enhanced linear selectivity compared with most of the analogous catalysts reported in recent studies. Polymers obtained were tested in two important reactions with potential industrial applications: as co-monomers for the synthesis of polyurethanes and as binders for 3D printers. The polyols-polyesters were obtained, with the average molecular weight ranging from 440 to 1050 Da. It is worth noting that the typical polyol polyester used in coatings is branched and has an average molecular weight of 2000–4000 Da. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Cellulose nanocrystal‐modified bio‐based aqueous polyurethane coating agent for kraft paper packaging.
- Author
-
Chen, Xin, Feng, Jianyan, Han, Shuaishuai, Bai, Yang, Wang, Peng, Liu, Haoqiang, Zhang, Peng, and Luo, Xiaomin
- Subjects
KRAFT paper ,POLYOLS ,POLYURETHANES ,CELLULOSE nanocrystals ,CONTACT angle ,FOOD packaging ,CELLULOSE - Abstract
With the implementation of the "plastic restriction order" and the demand for sustainable society development, biodegradable coatings derived from biomass materials have garnered significant interest. This study presents the synthesis of a double‐salt bio‐based waterborne polyurethane (PLA‐WPU) by utilizing poly(lactic acid) polyol (PLA) and isophorone diisocyanate (IPDI) as the main raw materials, along with 2,2‐dihydroxymethylpropionic acid (DMPA) and sodium ethylenediamine ethanesulfonate (A‐95) as a hydrophilic chain extender. Synergistic reinforcement of PLA‐WPU using hydrophobically modified cellulose nanocrystals (M‐CNC) and polycarbonate diimide (PDCDA). At an M‐CNC content of 3% relative to the effective mass of PLA‐WPU, the tensile strength reached 36.12 MPa. After 8 days a lipase PBS solution, the degradation rate reached 54%. Excellent waterproof performance was observed, exhibiting a contact angle of 143.5°. When applied as a surface coating on kraft paper, the Cobb 60 value decreased from 74.0 to 28.6 g/m2, while increasing the tensile strength by 451.3%. Importantly, the kraft paper maintained excellent waterproofing, mechanical strength, and high barrier properties even after repeated folding, high and low‐temperature conditions, and exposure to varying pH solutions. It proved to be both degradable and recyclable, making it a promising alternative to liner paper or plastic membrane, especially in food packaging. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Current Progress in Research into Environmentally Friendly Rigid Polyurethane Foams.
- Author
-
Makowska, Sylwia, Szymborski, Dawid, Sienkiewicz, Natalia, and Kairytė, Agnė
- Subjects
- *
URETHANE foam , *WASTE paper , *THERMAL insulation , *INSULATING materials , *HYDROGEN atom , *ISOCYANATES - Abstract
Polyurethane foams are materials characterized by low density and thermal conductivity and can therefore be used as thermal insulation materials. They are synthesized from toxic and environmentally unfriendly petrochemicals called isocyanates and polyols, which react with each other to form a urethane group via the displacement of the movable hydrogen atom of the −OH group of the alcohol to the nitrogen atom of the isocyanate group. The following work describes the synthesis of polyurethane foams, focusing on using environmentally friendly materials, such as polyols derived from plant sources or modifiers, to strengthen the foam interface derived from plant precipitation containing cellulose derived from paper waste. The polyurethane foam industry is looking for new sources of materials to replace the currently used petrochemical products. The solutions described are proving to be an innovative and promising area capable of changing the face of current PU foam synthesis. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Rational design of deep eutectic solvents for the stabilization of dehydrogenases: an artificial neural network prediction approach.
- Author
-
Radović, Mia, Tušek, Ana Jurinjak, Reiter, Tamara, Kroutil, Wolfgang, Bubalo, Marina Cvjetko, Redovniković1, Ivana Radojčić, Lozano, Pedro, and Álvarez, María Salomé
- Subjects
- *
ARTIFICIAL neural networks , *BIOCATALYSIS , *DEHYDROGENASES , *ENZYME inactivation , *EUTECTICS , *BACILLUS megaterium , *STRUCTURE-activity relationships , *VASOPRESSIN , *POLYOLS - Abstract
Stabilized enzymes are crucial for the industrial application of biocatalysis due to their enhanced operational stability, which leads to prolonged enzyme activity, cost-efficiency and consequently scalability of biocatalytic processes. Over the past decade, numerous studies have demonstrated that deep eutectic solvents (DES) are excellent enzyme stabilizers. However, the search for an optimal DES has primarily relied on trial-and-error methods, lacking systematic exploration of DES structure-activity relationships. Therefore, this study aims to rationally design DES to stabilize various dehydrogenases through extensive experimental screening, followed by the development of a straightforward and reliable mathematical model to predict the efficacy of DES in enzyme stabilization. A total of 28 DES were tested for their ability to stabilize three dehydrogenases at 30°C: (S)-alcohol dehydrogenase from Rhodococcus ruber (ADH-A), (R)-alcohol dehydrogenase from Lactobacillus kefir (Lk-ADH) and glucose dehydrogenase from Bacillus megaterium (GDH). The residual activity of these enzymes in the presence of DES was quantified using first-order kinetic models. The screening revealed that DES based on polyols serve as promising stabilizing environments for the three tested dehydrogenases, particularly for the enzymes Lk-ADH and GDH, which are intrinsically unstable in aqueous environments. In glycerol-based DES, increases in enzyme half-life of up to 175-fold for Lk-ADH and 60-fold for GDH were observed compared to reference buffers. Furthermore, to establish the relationship between the enzyme inactivation rate constants and DES descriptors generated by the Conductor-like Screening Model for Real Solvents, artificial neural network models were developed. The models for ADH-A and GDH showed high efficiency and reliability (R² > 0.75) for in silico screening of the enzyme inactivation rate constants based on DES descriptors. In conclusion, these results highlight the significant potential of the integrated experimental and in silico approach for the rational design of DES tailored to stabilize enzymes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Eco-friendly polyurethane composites with rice husk ash residue to remove petroleum hydrocarbons from aqueous media.
- Author
-
Pereira, Marcos Vinicius Vieira, Nunes, Eduardo Henrique Martins, Couto, Carmen, Ayres, Eliane, Oréfice, Rodrigo Lambert, Libânio, Marcelo, and Almeida, Marys Lene Braga
- Subjects
- *
RICE hulls , *DIESEL fuels , *POLYOLS , *URETHANE foam , *CONTACT angle , *POLYURETHANES - Abstract
Bio-based polyurethane foam sorbents were developed, incorporating different amounts of rice husk ash, 2, 8 and 20 wt% relative to the total mass of the polyols for the adsorption of diesel oil in single-phase and two-phase systems. The composites were characterized using scanning electron microscopy, microtomography, X-ray diffraction, infrared spectroscopy, thermogravimetry analysis and contact angle. In single-phase diesel oil systems, higher levels of ash incorporation (8 and 20%) increased the hydrocarbon removal capacity by up to 43% compared to pure polyurethane foam. Removals of up to 5.348 mg g−1 were found for the composite with 8% ash and 5.518 mg g−1 for the composite with 20%. In two-phase systems, varying the concentration of diesel oil from 10 g L−1 to 150 g L−1, there is a possibility that the lower contact angle of the composites may interfere with adsorption, as the composite with 2% ash tended to have a higher diesel oil sorption capacity. Sorption kinetics showed a high rate at contact times of around 8 min. The non-linear pseudo-second-order models fitted the observed sorption phenomena satisfactorily, with coefficients of determination greater than 0.90. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Adhesion and Cohesion Performance of Polyurethane Made of Bio‐Polyol Derived from Modified Waste Cooking Oil for Exterior Grade Plywood.
- Author
-
Maulana, Sena, Setiawan, Ika Putri, Pusbanarum, Dyah, Antov, Petar, Iswanto, Apri Heri, Kristak, Lubos, Lee, Seng Hua, and Lubis, Muhammad Adly Rahandi
- Subjects
- *
EDIBLE fats & oils , *METHYLENE diphenyl diisocyanate , *HEAT treatment , *SUSTAINABILITY , *PLYWOOD , *POLYOLS - Abstract
This study explored the feasibility of Waste Cooking Oil (WCO)‐based Bio‐Polyurethane (Bio‐PU) as an eco‐friendly alternative to petroleum‐derived polyols in plywood adhesives. The objective is to evaluate the impact of varied WCO concentrations and methylene diphenyl diisocyanate (MDI) levels on Bio‐PU and plywood performance. The Bio‐PU's characteristics, rheology, and functional groups are studied. Plywood made from three layers of 100 mm x 100 mm × 2 mm rubberwood (
Hevea brasiliensis ) veneer is bonded with Bio‐PU using a dual spread approach at 180 g.m−2, hot pressed at 120 °C and 1 MPa for 4 min. The laboratory‐fabricated plywood is tested for physical, mechanical, and adhesive properties. Results showed that Bio‐PU exhibited unique adhesive characteristics, with excellent adhesive strength, despite a slight decrease with higher WCO concentrations. WCO insertion do not compromise delamination resistance. FTIR analysis confirmed successful polyurethane chain synthesis. This research highlighted the potential of WCO‐based Bio‐PU's as a sustainable, high‐performance plywood adhesive. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
43. Digital Light Processing to Afford High Resolution and Degradable CO2‐Derived Copolymer Elastomers.
- Author
-
Poon, Kam C., Segal, Maddison, Bahnick, Alexander J., Chan, Yin Mei, Gao, Chang, Becker, Matthew L., and Williams, Charlotte K.
- Subjects
- *
SUSTAINABILITY , *THREE-dimensional printing , *ETHYLENE glycol , *MOLAR mass , *CARBON dioxide , *POLYOLS - Abstract
Vat photopolymerization 3D printing has proven very successful for the rapid additive manufacturing (AM) of polymeric parts at high resolution. However, the range of materials that can be printed and their resulting properties remains narrow. Herein, we report the successful AM of a series of poly(carbonate‐b‐ester‐b‐carbonate) elastomers, derived from carbon dioxide and bio‐derived ϵ‐decalactone. By employing a highly active and selective Co(II)Mg(II) polymerization catalyst, an ABA triblock copolymer (Mn=6.3 kg mol−1, ÐM=1.26) was synthesized, formulated into resins which were 3D printed using digital light processing (DLP) and a thiol‐ene‐based crosslinking system. A series of elastomeric and degradable thermosets were produced, with varying thiol cross‐linker length and poly(ethylene glycol) content, to produce complex triply periodic geometries at high resolution. Thermomechanical characterization of the materials reveals printing‐induced microphase separation and tunable hydrophilicity. These findings highlight how utilizing DLP can produce sustainable materials from low molar mass polyols quickly and at high resolution. The 3D printing of these functional materials may help to expedite the production of sustainable plastics and elastomers with potential to replace conventional petrochemical‐based options. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. Research progress of flame retarding modification of bio-based polyurethane.
- Author
-
DU Zedong, WU Lini, and YANG Guochao
- Subjects
- *
FIREPROOFING , *POLYURETHANES , *ENVIRONMENTAL protection , *RAW materials , *POLYOLS , *FIREPROOFING agents - Abstract
The research progress, existing problems and future development of flame retarding modification of bio-based polyurethane are summarized. The work summarized the research status of commonly used methods for preparing bio-based polyurethane, including basic characteristics, application effect and development prospect of various flame retardant agent. At present, vegetable oil-based polyols can effectively replace traditional industrial synthetic petroleum-based polyols as raw materials for the synthesis of bio-based polyurethane. However, there are still some shortcomings in this area that have not been addressed. The defects of polyurethane, such as flammability and smokiness, need to be improved. The practical application conversion rate of research results was not high. The environmental protection and safety performance of bio-based polyurethane can be further improved and enriched. Therefore, more efforts should be put into the above questions, which were all of great significance to the development of polyurethane. The research on retarding modification of polyurethane will have great development space and application value in the future. [ABSTRACT FROM AUTHOR]
- Published
- 2024
45. A diet low in fermentable oligo‐, di‐, monosaccharides and polyols improves abdominal and overall symptoms in persons with all subtypes of irritable bowel syndrome.
- Author
-
Dean, Gregory, Chey, Samuel W., Singh, Prashant, and Chey, William D.
- Subjects
- *
IRRITABLE colon , *MONOSACCHARIDES , *POLYOLS , *SYMPTOMS , *DIET , *NUTRITIONISTS , *LOW-FODMAP diet - Abstract
Background: A diet low in fermentable oligo‐, di‐, monosaccharides and polyols (LFD) improves symptoms in patients with irritable bowel syndrome (IBS). Previous studies have focused on patients with IBS and diarrhea (IBS‐D). It is unclear whether LFD is effective for IBS with constipation (IBS‐C) or IBS with mixed bowel habits (IBS‐M). This open‐label, real‐world study evaluates the relative effectiveness of the LFD among IBS subtypes. Methods: This study analyzes data from a service that provides low‐FODMAP meals to individuals with IBS. Participants met with a registered dietitian and completed the IBS symptom severity survey (IBS‐SSS) before and after undergoing a 2–4‐week period of FODMAP restriction. The primary endpoint was the proportion of participants with ≥50‐point decrease in IBS‐SSS between the three IBS subtypes. Key Results: After FODMAP restriction, 90% of participants with IBS‐D, 75% with IBS‐C, and 84% with IBS‐M met the primary endpoint (p = 0.045). Similar improvement was seen for a 100‐point decrease, but the difference between IBS subtypes was not significant (p = 0.46). After FODMAP restriction, all groups had statistically significant improvement in total IBS‐SSS as well as individual symptom categories. Improvement in IBS‐SSS subcategories was similar among the groups except for the categories of bloating severity (IBS‐M had greatest improvement) and bowel movement satisfaction (IBS‐C had less improvement). Conclusion & Inferences: Though the proportion of responders was highest for IBS‐D and lowest for IBS‐C, the LFD led to robust improvement in overall symptoms in all IBS subtypes. Key individual symptoms also showed significant improvements in all IBS subtypes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. FTIR Monitoring of Polyurethane Foams Derived from Acid-Liquefied and Base-Liquefied Polyols.
- Author
-
Dulyanska, Yuliya, Cruz-Lopes, Luísa, Esteves, Bruno, Guiné, Raquel, and Domingos, Idalina
- Subjects
- *
ACID-base catalysis , *URETHANE foam , *COMPRESSIVE strength , *ABSORPTION spectra , *DIBUTYLTIN , *POLYOLS , *FOAM - Abstract
Polyalcohol liquefaction can be performed by acid or base catalysis, producing polyols with different properties. This study compared the mechanical properties of foams produced using polyols from liquefied Cytisus scoparius obtained by acid and base catalysis and using two different foam catalysts. The differences were monitored using FTIR analysis. Acid-catalyzed liquefaction yielded 95.1%, with the resultant polyol having an OH index of 1081 mg KOH/g, while base catalysis yielded 82.5%, with a similar OH index of 1070 mg KOH/g. Generally, compressive strength with dibutyltin dilaurate (DBTDL) ranged from 16 to 31 kPa (acid-liquefied polyol) and 12 to 21 kPa (base-liquefied polyol), while with stannous octoate (TIN), it ranged from 17 to 42 kPa (acid) and 29 to 68 kPa (base). Increasing water content generally decreased the compressive modulus and strength of the foams. Higher water content led to a higher absorption at 1670 cm−1 in the FTIR spectrum due to the formation of urea. Higher isocyanate indices generally improved compressive strength, but high amounts led to unreacted isocyanate that could be seen by a higher absorption at 2265 cm−1 and 3290 cm−1. DBTL was shown to be the best foam catalyst due to higher trimer conversion seen in the spectra by a higher absorption at 1410 cm−1. Acid- and base-derived polyols lead to different polyurethane foams with different FTIR spectra, particularly with a higher absorption at 1670 cm−1 for foams from acid-derived liquefaction. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Harnessing leather waste in polymer matrix for sustainable smart shape‐stable phase change materials.
- Author
-
Sarkar, Jit, Samanta, Debasis, Chaudhuri, Saikat, Angeline, J., Kumari, K. G. Akshaya, and Jaisankar, Sellamuthu N.
- Subjects
PHASE change materials ,CASTOR oil ,SHAPE memory polymers ,POLYOLS ,GLYCIDYL methacrylate ,WASTE recycling ,POLYMERS ,LEATHER - Abstract
The utilization of leather waste (LW) in a polyurethane (PU) matrix makes a smart and novel shape stable phase change material (SSPCM). This is essential for sustainability as it reduces landfill waste after use. The PU is synthesized in bulk with a 90% yield, using biodegradable polycaprolactone diol and bio‐based polyol (castor oil), along with tolylene‐2,4‐diisocyanate. PL and PLG composites are prepared by blending of constituent components PU (P), LW (L), and poly(glycidyl methacrylate) (PGMA, G), as specified by their code names. Role of LW (hydrogen bonding and chemical crosslinking) and morphology are elucidated by FTIR and SEM, respectively. Self‐healing time (2 h), shape fixity ratios (Rf) (PL: 60–80% and PLG: 60–70%) and shape recovery ratios (Rr) (100% for both) are determined at 60°C. PLG displays faster shape recovery in water (<30 s) compared to air (>300 s). Shape stability and thermal properties of the SSPCM are examined using the temperature responsive leakage study, TGA, and DSC. This research introduces a new approach for using leather waste (LW) in SSPCM, with self‐healing and 100% Rr. This material may find application where SSPCM with high durability and flexibility is essential such as textile and footwear materials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Synthesis and properties of waterborne polyurethane acrylate emulsions with high bio‐based content.
- Author
-
Zhuang, Yu, Luo, Jiangyu, Duan, Xiaojun, Zhu, Yanan, and Qu, Jinqing
- Subjects
ACRYLATES ,POLYOLS ,POLYURETHANES ,EMULSIONS ,CASTOR oil ,DIFFERENTIAL scanning calorimetry ,CONTACT angle - Abstract
The bio‐based hydrophilic monoglycerol succinate was synthesized and reacted with bio‐based raw materials including polyols, pentamethylene diisocyanate, 1,4‐butanediol, to prepare the waterborne polyurethane acrylate (Bio‐WPUA) emulsions with high bio‐based content. The effect of bio‐based polyol categories including poly(trimethylene ether glycol), poly(tetrahydrofuran), and castor oil on the properties of Bio‐WPUA and its films were studied. The structure, thermal stability, crystallinity, contact angle, and mechanical properties of Bio‐WPUA film were characterized with fourier infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, X‐ray diffraction, contact angle analyzer, and mechanical tensile testing. It was found that Bio‐WPUA film containing poly(trimethylene ether glycol) as the soft‐segmented display good tensile stress, thermal stability, and water resistance with 1.38% of the water absorption rate, while Bio‐WPUA containing castor oil polyol as the soft‐segmented had good tensile strain and low‐temperature film‐forming properties with excellent film properties. The bio‐carbon content of Bio‐WPUA was high up to 40% according to ASTM D6866‐22, and possesses good physical mechanical and chemical resistance performance. The results provide theoretical guidance for the synthesis of polyurethane emulsions with bio‐based materials instead of petroleum‐based materials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Open-cell bio-based polyurethane foams modified with biopolyols from non-edible oilseed radish oil.
- Author
-
Malewska, Elżbieta, Kirpluks, Mikelis, Słota, Jagoda, Banaś, Joanna, and Kurańska, Maria
- Subjects
DIETHYLENE glycol ,POLYPROPYLENE oxide ,THERMOPHYSICAL properties ,RAW materials ,URETHANE foam ,POLYOLS - Abstract
Intensive research is currently being carried out worldwide to replace fossil raw materials with renewable ones or waste based on chemical synthesis. However, it is important that the newly developed raw materials do not conflict with global food production and recommend the use of non-edible or waste raw materials. Therefore, modified non-edible oilseed radish oil was used in the synthesis of polymeric materials. The functionalization of the oil was achieved through one-step, solvent-free transesterification process with triethanolamine, diethylene glycol, polypropylene glycol, ethylene glycol and propylene glycol. Biopolyols with hydroxyl numbers in the range of 237–346 mg KOH/g and different chemical structures were obtained. Open-cell polyurethane foams were produced by replacing 100% of the original petrochemical polyol with the biopolyols. The influence of the chemical structures of the biopolyols on the properties of the thermal insulation materials was analysed. The foams were characterised by low apparent densities of about 16 kg/m
3 . The type of biopolyol did not have a significant influence on the mechanical strength of the foams. A thermal analysis of the polyurethane biofoams was also carried out. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
50. Current Trends in the Use of Biomass in the Manufacture of Rigid Polyurethane Foams: A Review.
- Author
-
Dukarska, Dorota and Mirski, Radosław
- Subjects
URETHANE foam ,BIOMASS ,FILLER materials ,POLYOLS ,RAW materials ,BIOMASS production - Abstract
This paper discusses methods of using biomass from the agriculture, forestry, food and aquaculture industries as potential raw materials for bio-polyols and as fillers in the production of rigid polyurethane (RPUR) foams. Various aspects of obtaining bio-polyols are discussed, as well as the impact of replacing petrochemical polyols with bio-polyols on the properties of foams. Special attention is paid to the conversion of vegetable oils and lignin. Another important aspect of the research is the use of biomass as foam fillers. Chemical and physical modifications are discussed, and important factors, such as the type and origin of biomass, particle size and amount, affecting the foaming process, microstructure and properties of RPUR foams are identified. The advantages and disadvantages of using biomass in foam production are described. It is found that bio-polyols can replace (at least partially) petrochemical polyols while maintaining the high insulation and strength of foams. In the case of the use of biomass as fillers, it is found that the shaping of their properties is largely dependent on the specific characteristics of the filler particles. This requires further research into process optimization but allows for the fine-tuning of RPUR foam properties to meet specific requirements. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.