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Lignin can be used as a sustainable alternative to bisphenol A (BPA) to prepared lignin-based epoxy resins. Lignin effects including molecular weight, phenolic content, G/S unit ratio and flexible/rigid linkage ratio on epoxy synthesis and performance were summarized comprehensively. The incorporation of lignin with a higher molecular weight would lead to the higher rigidity of epoxy crosslinking network. Higher contents of ether bonds in lignin would provide higher structural flexibility of lignin incorporated epoxy thermosets. Lignin with higher contents of phenolic hydroxyls was more beneficial for improving the reactivity of its epoxy products after glycidylation. Due to the excellent charring capacity of lignin, higher contents of residue char can be produced at higher additions of lignin at high temperatures, while the loss of crosslinking density caused by the increasing lignin addition (especially for the macromolecular lignin) would deteriorate the thermal stability of their thermosets. Several applications of lignin-based epoxy resins were also mentioned based on their mechanical, thermal and chemical properties, such as coatings (with anticorrosion and UV-blocking), adhesives (with highly crosslinking network, excellent mechanical, and thermal properties) and flame retardants (with high charring capability). [Display omitted] [ABSTRACT FROM AUTHOR]

The dissolution behaviour of three corn starches, including corn starch (CS), high amylose corn starch (HACS) and waxy corn starch (WCS) with different amylose content in 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) were studied by comparing their dissolution state in ionic liquids (ILs). Further, the structural and thermal properties of the regenerated starch were analyzed. WCS with the lowest amylose content had the fastest dissolution rate, the most extensive structural damage, and the lowest solubility and required the maximum energy for dissolution. In the process of dissolution-regeneration, the A-type crystalline structure of WCS and CS was completely destroyed and transformed into an amorphous structure, while the B-type crystalline structure of HACS transformed into an ordered V -shaped structure. And the thermal stability of starch was improved after dissolution-regeneration in ILs. Among the two kinds of ILs, [AMIM] Cl had a better ability to dissolve starch, causing minor damage to the starch. [Display omitted] [ABSTRACT FROM AUTHOR]

Timoho fiber (TF) is a biodegradable bio-fiber rich in cellulose and a renewable agro textile fiber rich in cellulose polysaccharides. Isolation of micro cellulose from TF is an alternative reinforcement approach in a bio-composite application. This study characterized TF obtained from isolation employing FTIR, XRD, SEM-EDS, and TGA using hydrolysis. Pretreatment was done using alkaline, bleaching, and hydrolysis. FTIR confirmed that the maximum amount of noncellulosic materials had been removed from TF. The XRD result showed that hydrolysis treatment increased the crystal size and crystallinity index of the TF (88.68 %). TGA also revealed that the highest thermal stability had been found in the hydrolyzed TF. The micro cellulose TF represented an interesting source of cellulose reinforcing materials, and it might be continued in the form of nano cellulose. [ABSTRACT FROM AUTHOR]

Red grape pomace was used as a source for poly(3-hydroxybutyrate) (PHB) production, which was then subject to a range of purification processes. The different PHB biopolymers were characterized for chemical structure, crystallinity, thermal properties, colour, release of compounds into different food simulants and antioxidant inhibition, and comparisons were made with a commercially available PHB. An increase in purification steps did not have a significant effect on the high thermal stability of the extracted biopolymer, but it decreased the degree of crystallinity and the presence of amino acids and aromatic compounds. With additional purification, the PHB powders also whitened and the number of components released from the biopolymer into food simulants decreased. The released compounds presented antioxidant inhibition, which has not been previously reported in the literature or with commercially available polyhydroxyalkanoates. This is of great interest for food packaging and biomedical industries where the addition of antioxidant additives to improve PHB functional properties may not be necessary and could be avoided. [Display omitted] • Red grape pomace was used as a source for poly(3-hydroxybutyrate) (PHB) production. • The extracted PHB was then subject to a range of purification processes. • Crystallinity reduction was observed with further purification steps. • Aromatic impurities found in PHB migrated into hydrophilic food simulants. • The migrated impurities showed antioxidant activity. [ABSTRACT FROM AUTHOR]

The effects of gelatinization at three selected temperatures (DSC characteristic peaks temperature: T O , T P , and T C) and subsequent cold storage (CS) treatment on structural characteristics, pasting, and rheological properties of maize starch (MS) were investigated. The pasting, rheological properties of MS was changed with the increase of gelatinization temperature from T O to T C , but were not further significantly changed if the gelatinization temperature was higher than T C. Pasting and thermal properties analysis suggested that gelatinization at T C (TC treatment) significantly increased the gelatinization and pasting temperature of MS. Moreover, TC treatment decreased breakdown viscosity by 8.49 times and setback viscosity by 2.53 times. Dynamic rheological measurements revealed that the TC treatment caused the lower G' and G" of MS, and decreased the thickening coefficient by 55.17 %. These results indicated that TC treatment could enhance the thermal stability properties of MS, inhibiting the shear and short-term retrogradation, the shear-thinning behavior of MS. Interestingly, the CS treatment further inhibited the shear and short-term retrogradation and the shear-thinning behavior of MS. The leaked starch molecules aggregate to form a harder structure after gelatinization and starch molecules were further aggregated after CS treatment, these all were hypothesized to be responsible for these results. • Gelatinizations significantly changed the properties of maize starch. • Gelatinization at T C more effectively improved thermal and rheological properties. • Gelatinizations and cold storage inhibited shear and short-retrogradation. • Gelatinizations caused the starch leakage and aggregate to form a harder structure. [ABSTRACT FROM AUTHOR]

This study presents the preparation of cellulose micro-nanofibrils (CMNFs) from Enteromorpha (EP) and the application in PVA/acetylated distarch phosphate (ADSP)/CMNFs composite films. The Micro-nano scale, hydrophilicity, and strong hydrogen bond characteristics of CMNFs prepared form EP by acid hydrolysis were confirmed through the granular statistics, XRD analysis and chemical structure analysis. With the addition of CMNFs, the ultimate tensile strength and elongation at break of composite films are increased by 42.4 % and 90.3 %. An original Weibull statistical analysis shows the impact of CMNFs' added amount on strength distribution and ultimate stress. SEM and polarizing microscope images show the CMNFs' dispersion state in that films is optimal, when their addition was to be 2 %–3 % of total dry weight of PVA/ADSP matrix， which is consistent with the results of Weibull modulus analysis. The main thermal weight-loss process of the composite film is divided into four stages, CMNFs can significantly increase the thermostability at 280 °C to 400 °C. The experiment of water contact angle and water vapor transmission rate of the composite films confirmed that CMNFs can improve films' hydrophilicity. This study provides basis for the preparation of hydrophilic CMNFs and mechanism of modification study PVA-based composites. • High hydrophilic cellulose micro-nanofibrils prepared from Enteromorpha seaweed • The PVA based composite films modified by those fibrils have excellent performance. • Excellent hydrophilicity, mechanical properties, and improved thermal stability • Combining scanning electron and polarizing microscope to judge the morphology [ABSTRACT FROM AUTHOR]

Obtaining lignin-based graphite-like microcrystallites at a relatively low carbonization temperature is still very challenging. In this work, we report a new method based on condensed structures, for regulating graphite-like microcrystalline structures via the incorporation of 4,4′-diphenylmethane diisocyanate (MDI) into the main structure of lignin. The effects of MDI on the thermal properties of lignin and the graphite-like microcrystalline structure of lignin-based ultrafine carbon fibers were extensively studied and investigated. The incorporation of MDI decreased the thermal stability of lignin, increased the carbon yield and enhanced the formation of graphite-like microcrystallites, which are beneficial for reducing energy consumption during the preparation of lignin-based carbon fibers. The modified lignin-based ultrafine carbon fibers (M-LCFs) demonstrated satisfactory electrochemical performance, including high specific capacitance, low charge transfer resistance, and good cycle performance. The M-LCFs-3/2 electrode had a specific capacitance of 241.3 F g−1 at a current density of 0.5 A g−1, and a residual ratio of 90.2 % after 2000 charge and discharge cycles. This study provides a new approach to control the graphite-like microcrystalline structure and electrochemical performance while also optimizing the temperature. • Lignin-based carbon fiber with graphite structure was prepared at a low temperature. • Condensed structure facilitate the formation of graphite-like structure. • MDI decreased the thermal stability of lignin and energy consumption of carbon fiber. • MDI-modified lignin shows fascinating application in supercapacitor. [ABSTRACT FROM AUTHOR]

A self-assembled soluble nanoparticle, composed of common food biopolymers (carbohydrate, protein) and lipid, was previously reported by our laboratory. Although carrying capacity of valuable small molecules was demonstrated, physical functional properties are also important. Given the stabilization or destabilization characteristics of Hofmeister anion on macromolecular structures, mainly on proteins, here, we investigated the effects of different sodium salts composed of different Hofmeister anions on the structural and thermal properties of these self-assembled nanoparticles for improved functionalities. The salts were added into the mixture that was prepared in a diluted system during nanoparticle formation. Increased concentration of kosmotropic anions, in contrast to the chaotropic anion tested, resulted in nanoparticles with higher molar mass, hydrodynamic radius, and molecular density with more compact arrangement. The nanoparticles produced in presence of kosmotropic anions dissociated at higher temperatures and required higher enthalpies compared to the control sample. Spherical nanoparticles were formed for the kosmotropes with shear thinning behavior, contrary to rod-like nanoparticles for the chaotrope with near-Newtonian behavior. These findings help to gain an understanding of the effect of altering environmental conditions on the nanoparticles with an aim of producing desired structures for applications. • Effects of Hofmeister anions on a three-component nanoparticle were evaluated. • Anions affected the nanoparticle depending on their position in the Hofmeister series. • Kosmotropic anions significantly increased hydrodynamic radius of the nanoparticles. • Kosmotropic and chaotropic anions lead to different shapes (spherical vs rod). • Particles with kosmotrophs had higher thermal stability and shear-thinning behavior. [ABSTRACT FROM AUTHOR]

• PNS is a sustainable filler to develop cost-effective PLA biocomposites. • PNS enhanced PLA thermal stability, viscoelastic response, and crystallinity. • High filler loading did not cause significant decay in mechanical properties. • Ball milling of PNS further improved PLA thermal properties and melt fluidity. • Thermal annealing enhanced HDT, stiffness and strength of biocomposites. Biodegradable polymer composites reinforced with agri-food lignocellulosic biowaste represent cost-effective and sustainable materials potentially able to replace traditional composites for structural, household, and packaging applications. Herein, the preparation of polylactic acid (PLA)/pecan (Carya illinoinensis) nutshell (PNS) biocomposites at high filler loading (50 wt%) is reported, alongside the effect of two environmentally friendly physical treatments, namely ball-milling of the filler and thermal annealing on biocomposites. PNS enhanced the thermal stability, the viscoelastic response, and the crystallinity of the polymer. Furthermore, filler ball-milling also increased the melt fluidity of the biocomposites, potentially improving melt processing. Finally, the presence of PNS remarkably enhanced the effect of thermal annealing in the compounds. In particular, heat deflection temperature of the biocomposites dramatically increased, up to 60 °C with respect to the non-annealed samples. Overall, these results emphasize the potential of combining natural fillers and environmentally benign physical treatments to tailor the properties of PLA biocomposites, especially for those applications which require a stiff and lightweight material with low deformability. [ABSTRACT FROM AUTHOR]

Crowded environments, commonly found in the food system, are utilized to enhance the properties of soybean proteins. Despite their widespread application, little information exists regarding the impact of crowded environments on the denaturation behaviors of soybean proteins. In this study, we investigated how crowding agents with varying molecular weights, functional groups, and topology affect the denaturation behavior of glycinin under crowded conditions. The results reveal that thermal stability in PEG crowded environments is mainly influenced by both preferential hydration and binding. The stabilization is primarily enthalpy-driven, with aggregation contributing additional entropic stabilization. Specifically, ethylene glycol and diethylene glycol exhibit temperature-dependent, bilateral effects on glycinin stability. At the denaturation temperature, hydrophobic interactions play a predominant role, decreasing glycinin's thermal stability. However, at a molecular weight of 200 g/mol, there is a delicate balance between destabilizing and stabilizing effects, leading to no significant change in thermal stability. With the addition of PEG 400, 1000, and 2000, besides preferential hydration, additional hard-core repulsions between glycinin molecules enhance thermal stability. Methylation modification experiments demonstrated that 2-methoxyethyl ether exerted a more pronounced denaturing effect. Additionally, the cyclization of PEG 1000 decreased its stabilizing effect. [ABSTRACT FROM AUTHOR]

Micro-to-nano transformation can make a material unique. This research uses jute microfiber to extract Holo and Alpha forms of cellulose, which are later attempted to electrospun into superfine nanofibers (NFs). Initial investigation of morphological, physicochemical, crystallographic, and thermal properties confirmed successful synthesis of Holo and Alpha-cellulose (H/A-cellulose). Afterwards, the electrospinnable concentration of H/A-cellulose was optimized and their bead-free ultrafine NFs in the range of 109–145 nm were fabricated. FTIR analysis confirmed the source composition in Holo and Alpha CNF with the partial formation of trifluoroacetyl esters. Alpha CNF exhibited better structural integrity despite the crystallinity and thermal stability deteriorated in both Holo and Alpha CNF. Both Holo and Alpha CNF exhibited adequate mechanical performance and liquid uptake properties. Alpha CNF showed better morphological stability in organic solvents and slower biodegradation than Holo CNF. Subsequent investigation revealed that both Holo and Alpha CNF didn't exhibit cytotoxic effects on COS-7 cells and above 90 % of cells were viable in contact with both CNF. Significant proliferation and attachment of COS-7 cells were noticed within 7 days of incubation with the prepared CNF. Our findings revealed that jute-extracted cellulose can be a viable and potential source for constructing cellulose-based advanced nano-biomaterials. Graphical representation of the scaffold fabrication. [Display omitted] • Extraction of Holo and Alpha-cellulose from jute fiber • Fabrication of Holo and Alpha CNF via electrospinning • Alpha CNF was more structurally stable than Holo CNF. • Holo CNF and Alpha CNF have adequate surface-wetting and liquid uptake properties. • Both Holo CNF and Alpha CNF were non-toxic against COS-7 cells and favored excellent cell proliferation and attachment. [ABSTRACT FROM AUTHOR]

Having poor interfacial compatibility between biochar microsphere (BM) and polylactic acid (PLA) should be responsible for the unbalance of composite film strength and toughness. Elucidating the effect of polydopamine (PDA) on BM and BM/PLA composite films is the ultimate goal of this study based on the mussel bionic principle. It was found that the strong adhesion of PDA on the BM surface was achieved, which improved the surface roughness and thermal stability. Also, PDA modification can facilitate crystallization, increase thermal properties, improve interfacial compatibility, and enhance the tensile properties of BM/PLA composite films. Silane-based PDA modified BM/PLA composite film exhibited the best tensile strength, tensile modulus, and elongation at break with 77.95 MPa, 1.87 GPa, and 7.30%. These noteworthy findings, achieving a simultaneous improvement in PLA strength and toughness, hold promising implications for its sustainability. [Display omitted] [ABSTRACT FROM AUTHOR]

Applications for polylactic acid (PLA) are significantly impacted by its poor mechanical properties and lack of thermal stability. The goal of this work is to bridge the gap of poor compatibility among the components and enhance their interface interlocking capability to improve the toughness and thermal stability. Ultrafine bamboo charcoal (UFBC) was treated through deep eutectic solvent (DES) method to deposit sodium lignosulfonate (LS) on its surface. LS was used with PLA as a bio-coupling agent to create an eco-friendly PLA composite film with a wide range of characteristics. Benefiting from the penetration of PLA to the internal pores in UFBC, the resultant L-UFBC/PLA film has a good mechanical interlocking structure. Ls can increase the compatibility and strengthen the interface interlocking capability through DES method, which greatly improves the mechanical properties of the system. In comparison to pure PLA one, the elongation at break was 136.24 % greater, and the crystallinity (Xc) increased from 1.09 % to 3.33 %. Furthermore, the thermal stability of the system was also improved, and the residual at 600 °C rose by 4.83 %. These characteristics offer the prepared L-UFBC/PLA film a wide range of potential applications in the packaging, medical, agricultural, and other sectors. [ABSTRACT FROM AUTHOR]

Cardanol (CD) is used as a reactive compatibilizer, and blended with polylactic acid (PLA) and polypropylene carbonate (PPC) resin (70/30(w/w)) to obtain a series of PLA/PPC/CD blends. The systematic study was conducted on the thermal properties, optical properties, rheological properties, mechanical properties, and microscopic morphology of the blend, by varying amounts of CD added to the blends. A detailed explanation and comprehensive analysis of the reaction mechanism between CD and PLA/PPC have been made. The study found that CD acts as a "bridge" between the PLA and PPC, forming the structure of a block copolymer (PLA-b-CD-b-PPC), and the copolymer can greatly improve the compatibility of PLA and PPC. When the amount of CD reaches 8 wt%, only one T g is observed in the blend, simultaneously, PLA/PPC has already transitioned from a partially compatible system to a completely compatible system. At the same time, the addition of CD does not have any negative impact on the thermal stability of the PLA/PPC blend under processing temperature conditions, and the thermal stability of the PLA/PPC/CD blends can even be improved under extreme conditions. In addition, the addition of CD allows the PLA/PPC/CD blends to maintain a high light transmittance while reducing the opacity of the blend (the light transmittance remains above 92 %, and the opacity is reduced from 37 % to about 24 %), demonstrating excellent optical properties. Moreover, the elongation at break and impact strength of the PLA/PPC/CD blend both show a trend of first increasing and then decreasing with the increase of CD amount. When the CD amount varies within the range of 6– 8 wt%, the blends undergoes a brittle-ductile transition, and its toughness is greatly improved while the rigidity can also meet practical needs. When the amount of CD in the system increases to 12 wt%, the toughness of the blend reaches its peak, and its elongation at break and impact strength reach 513.24 % and 9211.5 J/m2 respectively (increased to 2442.84 % and 270.73 % of the PLA/PPC blend). Concurrently, the fracture surface of the blend exhibits large-scale plastic flow in the direction of the applied force, with marked shear yield phenomena, showing obvious characteristics of tough fracture. [Display omitted] [ABSTRACT FROM AUTHOR]

The aim of this study was to produce new nanocomposites with antimicrobial, antioxidant and anticancer properties that can be used in biomedical research based on carboxymethyl cellulose (NaCMC) biopolymer. First, poly(2-oxo-2-(pentafluorophenoxy)ethyl-2-methylprop-2-enoate) (PPFMA) was synthesized and characterized by FTIR and NMR techniques. It was then blended with NaCMC by in situ/hydrothermal method to produce a semi-synthetic functional material. Changes in the FTIR data of the blend and the single Tg value from DSC confirmed the compatibility of the blend. To enhance the thermal and biological properties of the NaCMC-PPFMA blend, biosynthesized Ag-ZnONPs were hydrothermally incorporated into the blend at different weight ratios. The prepared materials were characterized by SEM, EDX, TEM, XRD and FTIR. The thermal stability of the materials was determined by thermogravimetric analysis (TGA), and glass transition temperatures (Tg) was determined by differential scanning calorimeter (DSC). The oxidant, antioxidant, antimicrobial, and cytotoxic properties of PPFMA, Ag-ZnONPs, PPFMA-NaCMC blend, and nanocomposites were investigated in detail. The total oxidant state (TOS) value of the NaCMC-PPFMA blend, which was 0.72 μmol equivalent H 2 O 2 /L, increased to 7.2–10.4 μmol equivalent H 2 O 2 /L with the addition of Ag-ZnONPs. Ag-ZnONPs decreased total antioxidant state (TAS) levels of the nanocomposites while increasing their oxidant activity. Therefore, an increase in the antimicrobial activity of the nanocomposites was observed. Adding Ag-ZnONPs to the NaCMC-PPFMA blend increased the thermal stability by 22 °C and the Tg value by 9 °C. Finally, the potential of Ag-ZnONPs containing nanocomposites in wound healing therapies was examined. The findings suggest that nanocomposites prepared by incorporating Ag-ZnONPs into the semi-synthetic NaCMC-PPFMA blend can be a source of bio-safe raw materials and can be used as potential wound healers. [ABSTRACT FROM AUTHOR]

Biocomposites are materials that are easy to manufacture and environmentally friendly. Sugar palm fibre (SPF) is considered to be an emerging reinforcement candidate that could provide improved mechanical stiffness and strength to the biocomposites. Numerous studies have been recently conducted on sugar palm biocomposites to evaluate their physical, mechanical and thermal properties in various conditions. Sugar palm biocomposites are currently limited to the applications of traditional household products despite their good thermal stability as a prospective substitute candidate for synthetic fibres. Thus, thermal analysis methods such as TGA and DTG are functioned to determine the thermal properties of single fibre sugar palm composites (SPCs) in thermoset and thermoplastic matrix as well as hybrid SPCs. The biocomposites showed a remarkable change considering thermal stability by varying the individual fibre compositions and surface treatments and adding fillers and coupling agents. However, literature that summarises the thermal properties of sugar palm biocomposites is unavailable. Particularly, this comprehensive review paper aims to guide all composite engineers, designers, manufacturers and users on the selection of suitable biopolymers for sugar palm biocomposites for thermal applications, such as heat shields and engine components. [ABSTRACT FROM AUTHOR]

The present study investigated the effect of alkali treatment on the enhancement of Physico-chemical, tensile, thermal and surface properties of Symphirema involucratum stem fiber (SISF). The investigation of chemical constituents of optimally alkalized SISF revealed that ideal increment of cellulose content (68.69 wt%) and desired modification of other chemical components was accomplished through 60 min immersion period. An increase in the crystallinity index to 33.33% and small crystallite size to 3.21 nm was noted by X-ray diffraction analysis. Moreover, the treated fiber was found suitable for light-weight applications since physical analysis acknowledges that the density of the fiber augmented to 1424 kg/m3after surface treatment that reduces total weight percentage. The enhancements in tensile strength (471.2 ± 19.8 MPa), tensile modulus (5.82 ± 0.77 GPa) and thermal stability (371 °C) were noted that ensures the treated fiber has good mechanical and thermal properties required for composite preparation. These findings validated that the optimally surface-modified SISF is a suitable material for lightweight composite structures, for the time being. [ABSTRACT FROM AUTHOR]

In the frame of developing sustainable, eco-friendly and high performance materials, microcrystalline cellulose modified through silane coupling agent (MCC Si) is used as a reinforcing agent of benzoxazine resin to manufacture composites at different loadings of 5, 10, 15, 20 wt%. The structural, morphological and crystallinity characterizations of the modified MCC were initially performed to scrutinize the changes and confirm the modification. Then, an investigation on the crosslinking process of the prepared composites was held through curing kinetic study employing isoconversional methods. The kinetic data revealed a decrease in the average values of activation energy and the pre-exponential factor, particularly for composite supplemented with 10% MCC Si, whereas all samples disclosed a tendency of an autocatalytic curing mechanism. Furthermore, the study of the dynamic mechanical properties and degradation features of the cured specimens, respectively, indicated a superior stiffness attributable to the good interaction between BA-a and MCC Si, and enhanced thermal stability for the composites compared to pristine resin. • Microcrystalline cellulose was functionalized using silane coupling agent. • The structural, thermal and morphological occurring changes on MCC were investigated. • Effect of MCCSi on the curing kinetic, dynamic-mechanical properties and thermal stability of benzoxazine is studied. [ABSTRACT FROM AUTHOR]

Natural polysaccharides are concerned for their high biological activity and low toxicity. Two kinds of polysaccharides were extracted from Hippophae rhamnoide L. by microwave-assisted aqueous two-phase system. Under the optimal conditions predicted by RSM model (K 2 HPO 4 /ethanol (18.93 %/28.29 %), liquid to material ratio 77 mL/g, power 625 W and temperature 61 °C), the yield of total polysaccharides reached 35.91 ± 0.76 %. Moreover, the polysaccharides extraction was well fitted to the Weibull model. After purification by Sepharose-6B, the polysaccharides from top phase (PHTP, purity of 81.44 ± 1.25 %) and bottom phase (PHBP, purity of 88.85 ± 1.40 %) were obtained. GC, FT-IR, methylation and NMR analyses confirmed the backbone of PHTP was composed of a repeated unit →4)- β -D-Glc p -(1 → 2)- α -L-Rha p -(1 → 4)- β -D-Gal p -(1 → 4)- α -D-GalA p -(1 → 3)- α -L-Ara f -(1 → 3)- α -D-Man p -(1→, while the repeated unit in PHBP was →3)- α -L-Ara f -(1 → 2)- α -L-Rha p -(1 → 4)- β -D-Glc p -(1 → 3)- α -D-Man p -(1 → 4)- β -D-Gal p -(1 → 4)- α -D-GalA p -(1→. Compared with PHTP (6.46 × 106 g/mol), PHBP with relatively low molecular weight (8.2 × 105 g/mol) exhibited the smaller particle size, better water-solubility, thermal and rheological property, stronger anti-glycosylation and α -amylase inhibitory effects. Moreover, PHTP and PHBP displayed a reversible inhibition on α -amylase in a competitive manner. This study provides a high-efficient and eco-friendly method for polysaccharides extraction, and lays a foundation for sea buckthorn polysaccharides as potential therapeutic agents in preventing and ameliorating diabetes. [Display omitted] • MA-ATPE of two polysaccharides from sea buckthorn fruits was optimized by RSM model. • There were different repeated units in the backbone structures of PHTP and PHBP. • PHBP exhibited better physical and thermal stability, rheological property than PHTP. • PHTP and PHBP were novel natural agents for preventing and ameliorating diabetes. [ABSTRACT FROM AUTHOR]

Selective formation of stereocomplex (sc) crystallization in enantiomeric poly(L-lactic acid)/poly(D-lactic acid) (PLLA/PDLA) blends is considered as one of the most effective and promising way to improve the mechanical and thermal properties of polylactide (PLA) materials. However, homocrystallization (hc) prevails over sc crystallization in high-molecular-weight (HMW) PLLA/PDLA blends. Herein, we propose a simple and straightforward approach for fabricating sc crystallization and suppress hc crystallization for HMW PLLA/PDLA blends through the addition of C 70 as a nucleator. Non-isothermal crystallization and wide-angel X-ray diffraction studies demonstrate that, the incorporation of 1 wt% C 70 overwhelmingly leads to the formation of sc crystallites, while preventing the formation of hc crystallites. Isothermal crystallization experiments at 140 °C reveal a significant reduction in the half-crystallization period of the PLLA/PDLA blend upon the addition of C 70. Fourier-transformed infrared spectroscopy suggests that, the improved intermolecular interactions between PLLA and PDLA chains, as well as the inhibition of molecular chain diffusion and mobility, contribute to the accelerated formation of sc facilitated by C 70. The enhanced sc crystallization results in a 15.5 °C higher thermal stability in the as-prepared PLLA/PDLA blend with 1 wt% C 70 compared to the neat counterpart. • Sc crystallization for HMW PLLA/PDLA blends was exclusively promoted by a novel nucleator. • The nucleator not only selectively induced formation of sc crystallites, but also accelerated the crystallization rate. • The underlying nucleation mechanism of C 70 -promoted PLLA/PDLA blends was proposed. • The thermal stability of PLLA/PDLA blends was enhanced with addition of the nuclear agent. [ABSTRACT FROM AUTHOR]

This study evaluated the feasibility of using cactus mucilage (CM) to elaborate biobased composite films blended with styrene-butadiene rubber latex (SBL). The CM was extracted and precipitated with ethanol (CMET) and isopropanol (CMIS). Mucilage-based films were formulated using three levels of mucilage (4, 6, and 8 wt%). The microstructure, thickness, moisture content, density, water contact angle, water vapor permeability, film solubility, thermal stability, and toughness of mucilage films blended with SBL (SBL/CMET and SBL/CMIS) were measured. The properties of mucilage-based films varied systematically, depending on the concentration of mucilage. The addition of SBL to CM film produces compatible, hydrophobic, flexible, and stiffer films with low moisture contents and good barrier properties. The mucilage film incorporated with 6 wt% CMET and CMIS reached the highest Young's modulus of 1512 ± 21 and 1988 ± 55 MPa, respectively. The DSC of produced films reveals that the Tg of SBL/CMIS is lower than that of SBL/CMIS. The synthesized films were structurally stable at high temperatures. The biodegradability of the composite films buried in the ground shows that the produced films are 100 % biodegradable after 40 days. Thus, CM blended with SBL can benefit specific applications, especially food packaging. [ABSTRACT FROM AUTHOR]

The carboxymethylated (1 → 6)-α-dextran (CM-dex) was synthesized by introducing carboxymethyl groups at different degrees of substitution (DS). The resulting dex1-1, dex2-1, dex3-1, and dex4-1 products had degrees of substitution of 0.57, 0.78, 1.13, and 1.25, respectively. The dex3-1 showed the highest glass transition temperature (T g) of 215.96 °C, whereas T g of pure dextran was 149.83 °C. TGA results indicated that the residual loss was reduced along with the increase of DS in the high-temperature region (450–600 °C). Besides, the CM-dex had stronger scavenging capacity against OH radicals but lower scavenging capacity for DPPH (1,1-diphenyl-2-picrylhydrazyl) radicals compared to that of pure dextran. The carboxymethylation of (1 → 6)-α-dextran will extend the applications for modified dextran. • The (1 → 6)-α-dextran is carboxymethylated with chloroacetic acid. • Carboxymethylation improved the thermal stability of dextran. • Dex3–1 had the highest T g of 215.96 °C. • The OH radical scavenging ability of dextran increased with degree of substitution. [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils (CNFs) with cellulose I and II allomorphs were efficiently prepared by sulfuric acid hydrolysis of eucalyptus cellulose under three different conditions followed by mechanical treatments: (i) classical sulfuric acid hydrolysis of cellulose I (CNF-I), (ii) sulfuric acid hydrolysis of mercerized cellulose II (MNF-II), and (iii) solubilization and hydrolysis of cellulose I by concentrated sulfuric acid and subsequent recrystallization in water (RNF-II). Crystal structure, surface chemistry, morphology and thermal properties of three CNFs were investigated and compared. Three CNFs of 2–10 wt% were mixed with PVA to prepare biodegradable composite films. CNF allomorph had significant impact on crystal structure, mechanical and thermal properties of the PVA composites. The maximum Young's modulus of CNF-I/PVA, RNF-II/PVA and MNF-II/PVA were increased by 62, 32 and 44%, respectively. Addition of CNFs raised onset degradation temperature (T onset) and thermal decomposition temperature (T max) of PVA nanocomposite, while decreased the melting temperature (T m). Temperature window (T onset − T m) for the melt processing of nanocomposites (10 wt% CNF loading) were increased 2.8, 3.2 and 2.5 times for CNF-I/PVA, RNF-II/PVA and MNF-II/PVA, respectively. All composite films remained excellent transparency with addition of CNFs. This comparative study provided important knowledge of selecting CNF allomorph for fabrication of high-performance CNF/PVA composites. Unlabelled Image • Three CNFs with cellulose I or II allomorph were efficiently prepared from eucalyptus. • CNF allomorphs exhibited different enhanced performances on PVA composite films. • PVA composite films had wider temperature window (T onset − T m) for melt processing. • PVA composite films enhanced with CNF-I (II) exhibited excellent transparency. [ABSTRACT FROM AUTHOR]

A major challenge in the chronic wound healing is a self-care wound dressing. The problem in chronic wounds is the lack of functional extracellular matrix to stimulate healing. The extracellular matrix is a network of proteins and polysaccharides that serves as physical framework and provides regulatory signals. The primary goal is to mimic the property of the extracellular matrix with Silk Fibroin and Paramylon to produce a novel bioactive film. Silk fibroin is a fibrous protein having unique mechanical properties and tunable biodegradability that makes it favourable for tailoring to specific applications. Paramylon is a β-glucan that possess a broad spectrum of biological activity that enhances the immune response. Silk fibroin/paramylon blend films have been prepared by solution casting and were examined for structural, thermal, mechanical and other physical properties for knowing its transformation for chronic wound healing. It was observed that the fibroin films shows high thermal stability, high hydrophobicity, high stiffness value whereas the paramylon film show good water absorption property and both fibroin and paramylon shows good blood compatibility and was non-toxic as well. It also confirms that the blended films showed a combination of fibroin and paramylon property at different concentrations without any chemical interaction. [ABSTRACT FROM AUTHOR]

In this study, gelatin (GE) was composited with chitosan films (CH) and chitosan films incorporated with curcumin nanoemulsion (CH-CNE) through blending and layer-by-layer (LbL) assembly in order to overcome the physical limitations of the chitosan and its incorporated films. Furthermore, the distinctive effects of blending and LbL assembly on the physicochemical parameters of the composite films were assessed. The composite LbL films incorporated with GE exhibited improvement of water vapor barrier, tensile strength, solubility, which contributed to the enhanced antioxidant activity from the single components. By contrast, the composite films of the blending method exhibited greater elongation at break and increased swelling degree. Additionally, the films containing the nanoemulsion exhibited reduced light transmission and increased opacity. The thermal properties indicating the thermal stability and compatibility interactions of the composite films were examined by the glass transition temperature (T g). Results revealed that the distinctive behavior of the T g was affected by the compositing method. The LbL films exhibited substantially increased T g , indicating enhanced thermal stability. The results indicated that the composited films formed via the LbL assembly attained better physicochemical properties and thermal stability, implying higher compatible film than the blending. • Limitations of chitosan film (CH) were improved by compositing with gelatin. • Antioxidant activities were improved by incorporating curcumin nanoemulsion (CurNE). • Blended films exhibited increased elongation values and swelling degree. • LbL films exhibited a higher water vapor barrier, tensile strength, and solubility. • LbL method increased the antioxidant activity of chitosan incorporated with CurNE. [ABSTRACT FROM AUTHOR]

To investigate the effect of heat-moisture treatment (HMT) on the physiochemical properties and in vitro digestibility of corn starch, the pasting behavior, viscoelasticity, thermal properties, long/short range structure, morphology and in vitro digestion of corn starch treated with different HMT conditions (HMT-20, 25, 30, 35 and 40 %) were characterized. Results indicated that after HMT, the pasting and disintegration behaviors of corn starch were affected and correlated with the moisture content. The dynamic viscoelasticity of corn starch was changed, and when glassy conditions were reached, the elastic properties decreased with increasing moisture while the viscous properties increased, especially for the HMT-40 %. The thermal stability of starch was improved by HMT, although the enthalpy of pasting (ΔH) was reduced. Additionally, the HMT processing also promoted the conversion of RDS to SDS and/or RS (SDS and RS increased to 39.80 % and 31.68 % for HMT-40 %, respectively), which might attribute to the rearrangement of free starch molecules. The present work provides a potential approach to make functional starches with healthy properties. [Display omitted] • Gelatinization behavior of starch was changed by heat-moisture treatment. • Heat-moisture treatment promoted the heat resistance of corn starch. • The in vitro digestion of corn starch was reduced by heat-moisture treatment. [ABSTRACT FROM AUTHOR]

Organic onium hydroxide aqueous solutions (OHAS) are demonstrated to be potential solvents for the dissolution of lignin and its epoxidation. A series of OHAS has been assessed in terms of the solubility of soda lignin (SL) and Klason lignin (KL), which are moderately and rarely soluble in NaOH aq. soln., respectively. Tetrabutylphosphonium hydroxide ([P 4444 ]OH) aqueous solution was found to exhibit a highest solubility, specifically 40 wt% of SL and 3.0 wt% of KL. The superior solubility of OHAS is comprehended to be due to weak interactions between OH anions and phosphonium cations, and hence OH anions interact effectively with lignin. Epoxidation of SL was achieved by simply adding epichlorohydrin to [P 4444 ]OH aq. dissolving SL. Films of epoxidized SL were prepared by thermal curing with the aid of a crosslinking agent, and the films were found to possess high thermal stability of >250 °C and excellent ductility. The thermal and mechanical properties were controllable by the concentration of [P 4444 ]Cl as an additive. [ABSTRACT FROM AUTHOR]

In this study, poly(2-(3,5-dichloroanilino)-2-oxoethyl 2-methylprop-2-enoate) (PDCOEMA), a new synthetic polymer based on methacrylate, was synthesized and characterized. The blend of PDCOEMA with chitosan (CS) was prepared by the hydrothermal method and the DSC technique confirmed its formation. It was observed that PDCOEMA increased the thermal stability and glass transition temperature (Tg) of CS. The Tg value of the PDCOEMA-CS blend was increased at about 7 °C with the highest ZnO NPs contribution rate. PDCOEMA-CS/ZnO nanocomposites were prepared by adding ZnO NPs produced by biosynthesis at different weight ratios to the PDCOEMA-CS blend by hydrothermal method. When the thermal stability of nanocomposites determined by TGA was examined, it was observed that it increased significantly compared to CS. While the initial decomposition temperature of CS was 270 °C, this value increased to 293 °C after blending with DCOEMA, and to 317 °C with the addition of 7 % ZnO NPs. Antimicrobial, anticancer, cytotoxic, antioxidant, and wound healing properties of PDCOEMA, CS, PDCOEMA-CS blend, and nanocomposites were determined. According to the obtained results, it was observed that nanocomposites containing 5 % and 7 % ZnO NPs showed good anticancer activity against A549 cells at a dose of 10 μg/mL. The results show that the produced nanocomposites can contribute to developing CS-based materials. [ABSTRACT FROM AUTHOR]

Soil burial degradation was confirmed to be an efficient waste disposal method for the biodegradable materials with short service life, such as starch/poly (lactic acid) (PLA) composite. The biodegradation behavior about chemical and thermal properties of starch/PLA composite was analyzed by using X-ray photoelectron spectroscopy (XPS), infrared microscopy (IRM), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). XPS and IRM results indicated that the biodegradation of PLA occurred at the ester groups in PLA chains. XPS demonstrated the cleavage of C O linkages between glucose rings in starch. DSC and TGA results showed that the starch/PLA composite degraded faster than the pure PLA. During the soil burial degradation, the glass transition temperature of starch/PLA composite exhibited an obviously decrease while it had a slight variation for PLA. The thermal stability of starch/PLA composite shifted towards to that of PLA when they were subjected to soil burial for the same time. It is established that the starch can accelerate the degradation of PLA-based materials, which will enlarge the markets of biodegradable PLA materials used for short service life products. [ABSTRACT FROM AUTHOR]

Pectinase produced by a honey derived from the fungus Aspergillus awamori KX943614 was covalently immobilized onto gel beads made of alginate and agar. Polyethyleneimine, glutaraldehyde, loading time and enzyme's units were optimized by 2 4 full factorial central composite design (CCD). The immobilization process increased the optimal working pH for the free pectinase from 5 to a broader range of pH 4.5–5.5 and the optimum operational temperature from 55 °C to a higher temperature, of 60 °C, which is favored to reduce the enzyme's microbial contamination. The thermodynamics studies showed a thermal stability enhancement against high temperature for the immobilized formula. Moreover, an increase in half-lives and D-values was achieved. The thermodynamic studies proved that immobilization of pectinase made a remarkable increase in enthalpy and free energy because of enzyme stability enhancement. The reusability test revealed that 60% of pectinase's original activity was retained after 8 successive cycles. This gel formula may be convenient for immobilization of other industrial enzymes. [ABSTRACT FROM AUTHOR]

To obtain a safe and biodegradable material for food packaging, this study developed a facile and green process of anchoring nisin onto oxidized cellulose through a simple Schiff base reaction for long-term antimicrobial active food packaging. To the best of our knowledge, this is the first report of such a packaging. The grafting reaction between the amino groups of nisin and the aldehyde groups of oxidized cellulose films was successfully established to obtained a nisin anchored cellulose films (NC) membrane; the structure was characterized with Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The NCs membrane had an outstanding transparent property of above 90% transmittance through 300 nm to 800 nm; while, the barrier properties against oxygen remain excellent. The thermal stability of the NCs membrane remained excellent and enabled an easier degradation than the original cellulose membrane. The NCs membrane displayed good antimicrobial activity against Alicyclobacillus acidoterrestris DSM 3922T in a long-term way, thus demonstrating good potential as food packaging material. The obtained results are promising and confirm the development of NCs membranes as green materials for food packaging. [ABSTRACT FROM AUTHOR]

In this work, chitin-curcumin based polyurethane elastomers (PUEs) were prepared by step growth polymerization technique using hydroxy terminated polybutadiene (HTPB), hexamethylene diisocyanate (HDI), chitin and curcumin. The molecular characterization was done by using FTIR and SS 1 HNMR techniques. The surface morphology and thermal stability was studied by scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA), respectively. Degree of absorption and swelling characters were also determined in water as well as in DMSO. The crystalline behavior of prepared elastomers was checked by using X-ray diffraction (XRD) and differential scanning calorimeter (DSC). Results presented that crystallinity of elastomers increased by increasing the content of chitin due to formation of more ordered structure. [ABSTRACT FROM AUTHOR]

The structure and thermal properties of pulsed electric field (PEF) assisted sodium hypochlorite oxidized starch were investigated. The carboxyl content of the oxidized starch was increased by 25 % when compared with the traditional oxidation method. Dents and cracks were evident on the surface of the PEF-pretreated starch. Compared with native starch, the peak gelatinization temperature (T p) of PEF-assisted oxidized starch (POS) was reduced by 10.3 °C, while that of the oxidized starch without PEF treatment (NOS) was only reduced by 7.4 °C. In addition, PEF treatment further reduces the viscosity and improve the thermal stability of the starch slurry. Therefore, PEF treatment combined with hypochlorite oxidation is an effective method to prepare oxidized starch. PEF showed great potential in expanding starch modification, to promote a wider application of oxidized starch in the paper, the textile and the food industry. • The carboxyl content of POS was increased by 25 % when compared with the NOS. • Some dents and cracks appeared on the surface of PEF-pretreated starch. • Gelatinization temperature of the POS reduced drastically after dual modification. • POS can reduce the peak viscosity and improve the thermal stability of starch slurry. [ABSTRACT FROM AUTHOR]

Cress seed gum (CSG) was fractionated using stepwise extraction with water, yielding three fractions (F1, F2, F3) whose average molecular weights ranged from 863 to 1080 kDa. The chemical composition (monosaccharide, ash, moisture, CHN and uronic acid contents) and molecular weight of the fractions varied significantly. Generally, the major identical peaks of FT-IR spectra for three fractions and whole cress seed gum were similar. The results of DSC and TGA indicated that F3 had the highest thermal stability and considering the initial decomposition temperature, the decreasing order of thermal stability was F3 > F2 > F1. Cress seed gum and its fractions exhibited non-Newtonian shear thinning behavior which the Herschel-Bulkley model was successfully described the steady shear flow behavior of samples, and apparent viscosity followed the order of F3 > F2 > F1. F3 exhibited the best surface tension reducing ability compared to other fractions and CSG. All the samples had good emulsifying capability (>97%) and stability (>96%). The emulsion capacity increased slightly along the series of F1, F2 and F3, whereas, emulsion stability decreased along the same series. CSG and F3 showed the highest and the lowest foaming capacity and stability, respectively. [ABSTRACT FROM AUTHOR]

A blend of poly( l -lactide) (PLLA) with star-shaped poly(ɛ-caprolactone-co- l -lactide) (s-PCLA) at different contents (PLLA/s-PCLA = 100/0, 90/10, 80/20, and 70/30, w/w) were prepared by torque rheometer. Thermal and functional properties of the blends were investigated by FTIR, SEM, DSC, TGA, DMA, tensile, optical, and water vapor permeability tests. FTIR results showed that intermolecular hydrogen bonds existed between two components in the blends. SEM indicated that PLLA and s-PCLA showed limited miscibility. DSC showed that T g occurred at lower temperatures in the PLLA/s-PCLA blends than in neat PLLA, and the crystallinity of PLLA phase increased by the presence of s-PCLA in the PLLA/s-PCLA blends. TGA indicated that s-PCLA improved the thermal stability of the PLLA/s-PCLA blends. DMA results revealed that the storage modulus of the composites decreased with respect to the pure polymer. The result of tensile tests suggested that the PLLA/s-PCLA blends showed better elongation at break than neat PLLA. The effect of s-PCLA on the color and opacity of films could be considered as negligible. The WVP of PLLA/s-PCLA blend films increased with the increase in s-PCLA, and they were still lower than that of commercial LDPE films. [ABSTRACT FROM AUTHOR]

Abstract: Cellulose acetate (CA) was modified using N-(phenyl amino) maleimides (R-APhM) where, R H or 4-NO2. The structure of the modified polymer was characterized by 13C-NMR. The chemical modification is based on the reaction between the acetyl group of the glucopyranose ring in cellulose acetate and the proton of the amino group in N-(phenyl amino) maleimide molecule. The thermal gravimetry (TGA) was used to investigate the thermal stability of the modified polymeric samples. The modified cellulose acetate by 4-nitro (phenyl amino) maleimide (CA/4-NO2APhM) exhibits the highest thermal stability as compared to the N-(phenyl amino) maleimide (CA/APhM) and the unmodified CA. The crystallinity and morphology of the modified polymeric samples were investigated using X-ray diffraction (XRD) and emission scanning electron microscope (ESEM), respectively. The presence of N-(phenyl amino) maleimide moieties in the cellulose acetate matrix improved its mechanical property. Also, the organic nature of (R-APhM) moieties inside CA matrix reduced its wettability. [Copyright &y& Elsevier]