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[Display omitted] • Two biobased low viscosity photoactive benzoxazine monomers are synthesized. • DLP 3D printing can be conducted without adding diluent. • The 3D printing benzoxazine thermosets show high heat resistance. Preparing biobased benzoxazine resin through vat photopolymerization 3D printing is of great significance for its sustainable development and application in cutting-edge fields. In this work, biobased guaiacol and eugenol are used as phenol sources, while 2-(2-aminoethoxy) ethanol with flexible ether bonds is used as an amine source to create photoactive benzoxazine monomers, Eu-BzMA and Gu-BzMA. The viscosity of both monomers at room temperature is lower than 150 mPa·s, which can satisfy the requirements of digital light processing (DLP) 3D printing without adding diluents. The thermal and mechanical properties of the 3D printing benzoxazine resins are studied and the relationship between structure and properties is discussed by comparing the two molecules. Eu-BzMA resin has higher thermal decomposition temperature (T 5 = 343 °C), higher hardness (0.70 GPa), higher flexural stress (43.5 MPa) and flexural moduli (2.71 GPa); while, Gu-BzMA resin has higher glass transition temperature (176 °C). This is because Eu-BzMA resin shows higher cross-linking density, but contains more flexible structures formed by allyl crosslinking. In this article, a preparation strategy of low viscosity biobased photoactive benzoxazine is proposed and successfully applied to vat photopolymerization 3D printing. [ABSTRACT FROM AUTHOR]

[Display omitted] • A self-healing and reprocessable biobased NIPU elastomer was designed and synthesized. • The elastomer showed high healing efficiency of 97.5 % after healing at room temperature for 24 h. • The tensile strength of the elastomer after three reprocessing cycles reached 136.1% of the original one. • The elastomer-based flexible strain sensor was successfully applied for human motion detection. Owing to the nontoxicity of monomers, non-isocyanate polyurethane elastomers have attracted considerable attention, yet the synthesis and functionalization are still challenging. Herein, self-healing and reprocessable biobased non-isocyanate polyurethane (NIPU) elastomers with dual dynamic covalent adaptive network (DDCAN) by disulfide bonds and dynamic imine bonds were synthesized as substrate for the construction of flexible strain sensor with MXene as conductive substance. The tensile strength and elongation at break of the NIPU elastomer were 3.22 MPa and 234 %, respectively. Thanks to the formation of DDCAN, the NIPU elastomer showed high healing efficiency of 97.5 % after healing at room temperature for 24 h. Interestingly, the NIPU elastomer possessed superior reprocessing capability and the tensile strength after three reprocessing cycles reached 136.1 % of the original one, which was attributed to the increase of crosslinking points caused by topological rearrangement. In addition, the NIPU elastomer-based flexible strain sensor exhibited fast response (response time = 60 ms) and excellent repeatability (1000 bending-releasing cycles) and was successfully applied for human motion detection and speech recognition. The findings in this work conceivably stand out as a new methodology for the preparation of biobased and functional elastomers, which will greatly promote the sustainable development and application of flexible electronics. [ABSTRACT FROM AUTHOR]

Earlier studies of β-Myrcene (Myr)/ β-ketoester functional (acetoacetoxy)ethyl methacrylate (AAEMA) copolymers exhibited compositional drift, leading to ambiguity in microstructure/thermomechanical property correlations while shape memory recovery times were excessively long ~1 h. The terpene-based 1,3-diene Myr and AAEMA were copolymerized via nitroxide-mediated polymerization (NMP) with an initial Myr molar feed ratio ranging from 0.1 to 0.9. Reactivity ratios estimated by the Meyer-Lowry method were r Myr = 0.20 and r AAEMA = 0.22 with respective 95% confidence intervals of [0.13, 0.37] and [0.15, 0.23], suggesting alternating copolymerization. Bulk terpolymerization with styrene (Sty) afforded linear poly(Myr- stat -Sty- stat -AAEMA) prepolymers designed to modulate glass transition temperature T g and stiffness. Subsequent cross-linking with isophorone diamine (IPDA) formed catalyst-free vinylogous urethane dynamic linkages. ATR-FTIR, dynamic mechanical analysis (DMA), and tensile measurements confirmed the recyclability of vitrimers through hot pressing at 110 °C, demonstrating minimal changes in rheological and mechanical properties even after four cycles. By heating the vitrimers to above their T g (to ~45 °C), they exhibited a shape memory effect with high shape fixity and fast shape recovery (< 1 min). The vitrimers could undergo permanent shape reprogramming through reconfiguration of dynamic bonds at ~110 °C. This work shows the adaptability of Myr-based rubbers by vitrification and appropriate copolymerization for the synthesis of more sustainable elastomers with stimuli responsive properties. [Display omitted] • Myrcene/AAEMA copolymers have alternating microstructure (r Myr = 0.20 and r AAEMA = 0.22) with respective 95% confidence intervals of [0.13, 0.37] and [0.15, 0.23]. • Catalyst-free vinylogous urethane vitrimeric rubber poly(Myrcene- stat -Styrene- stat -AAEMA) vitrimeric rubbers with isophorone diamine made • Vitrimer was recycled up to 4 times without deterioration of rheological, tensile, and thermomechanical properties • Vitrimers exhibited reprogrammable shape memory effect with good shape fixity and rapid shape recovery. [ABSTRACT FROM AUTHOR]

The design of polymer-based composites possessing good mechanical and self-healing properties remains a challenge in the development of high-performance self-healing materials. In this study, we used two-dimensional polyamide (2DPA), biomass rosin ester, and a dynamic crosslinking agent poly (urethane-urea) as raw materials, and prepared biomass rosin-based composites via in situ polymerization. The composites with 1 wt% 2DPA exhibited excellent self-healing properties (self-healing efficiency of 94 % after 24 h at 80 °C) and mechanical properties (tensile strength = 7.8 MPa). Moreover, the composites were applied to anticorrosion and antimicrobial coatings, which possessed excellent anticorrosion and antimicrobial properties. This study provides a new strategy for developing high-performance bio-based self-healing composites. [Display omitted] • Rosin-based self-healing functionalized composites prepared by compositing two-dimensional polymers with biobased materials. • Introducing two-dimensional polymers into composites can effectively balance their self-healing and mechanical properties. • Composites have excellent anticorrosion and antimicrobial properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • Biobased thermoset from soybean oil and cinnamon derivates showed enhanced flexural strength at optimal curing temperatures. • Materials demonstrated increased flexural strength up to 6.4 MPa at optimized curing temperatures of 130 °C. • Thermal stability improved significantly, achieving a glass transition temperature from –32 °C up to 10 °C. • Allyl cinnamate act as a reactive diluent reduced viscosity facilitating improved fiber impregnation. The study successfully developed thermoset materials utilizing acrylate epoxidized soybean oil (AESO) and allyl cinnamate (ACIN) with tert -butyl peroxybenzoate (TBPB) as the initiator. Isothermal curing at temperatures between 110 °C to 140 °C of the developed formulations, showed that higher temperatures accelerated the conversion process. The higher curing temperature increased the degree of conversion, leading to obtain the best flexural strength for samples cured at 130 °C. However, samples cured at 120 °C exhibited better impact properties due to a lower degree of conversion, which allows for a more mobile reticular network. In addition, morphological observations confirmed these mechanical property trends. Dynamic thermal characterization revealed changes in glass transition temperature and exothermic reactions due to unreacted products appeared for materials cured at low temperature. Increasing curing temperature allowed to enhance thermal stability by increasing molecular weight. Finally, thermomechanical analysis confirmed stiffness and glass transition temperature increases observed during flexural tests and thermal characterization. [ABSTRACT FROM AUTHOR]

Carbon–carbon backbone polymers are non-biodegradable, persistent plastics that have accumulated on land and oceans due to human activities. They degrade and fragment into microplastics and smaller particle sizes but do not biodegrade at an acceptable and practical rate. Their continual buildup in the natural environment precipitates serious detrimental impacts on human health and the environment, as extensively documented in the literature and media. Nearly 77% of global plastics produced are carbon–carbon backbone polymers. More importantly, 90% of packaging plastics (153.8 million metric tons) are non-biodegradable, persistent carbon–carbon backbone polymers. The recycling rate of these non-durable packaging plastics ranges from 0 to 4%. Re-designing carbon–carbon backbone polymers to labile ester backbone biodegradable–compostable polymers and treating them along with biodegradable organic waste (such as food, paper, and organic wastes) in managed industrial composting is environmentally responsible. Diverting 1 million metric tons of biodegradable organic wastes in MSW bound for landfills and open dumps to industrial composting results in 0.95 million metric tons CO2 equivalents of GHG emissions reduction. This perspective paper discusses strategies and rationales regarding the redesign of carbon–carbon backbone polymer molecules. It describes the carbon footprint reductions achievable by replacing petro-fossil carbon with plant biomass carbon. Biodegradability and compostability are frequently used but misunderstood and misused terms, leading to misleading claims in the marketplace. This paper presents the fundamentals of biodegradability and compostability of plastics and the requirements to be met according to ASTM/ISO international standards.

Foams produced with biobased materials, such as poly(lactic acid) (PLA), cellulose, starch, and plant oil-based polyurethanes, have become more and more important in the circular economy. However, there are still significant challenges, including inferior performance and higher cost. The use of low-cost filler material has the potential to reduce the cost and alter the composite properties of biobased foams. By selecting biofillers derived from plant material, we can reduce the cost without sacrificing the compostability. This study explored the impact of landfill-diverted biofiller material, ground coffee chaff and rice hulls on the physical properties of biobased foams. Both biofillers were extrusion compounded with PLA, then extruded into rigid foams using a physical blowing agent. A filler concentration up to 10 weight % rice hull or 5 weight % coffee chaff could be incorporated without a significant increase in density, in comparison to the regular PLA foam. The thermal conductivity was similarly unaffected by biofiller loading, with values ranging between 71.5 and 76.2 mW/m-K. Surprisingly, the filler composite foams possessed impressive mechanical properties with all compressive moduli above 300 MPa. Only 5 weight % loading resulted in the doubling of compressive modulus, compared to the regular PLA foam. These results indicate that landfill-diverted fillers can strengthen foam mechanical properties without impacting thermal insulation performance, by forming reinforcing networks within the cell walls. [ABSTRACT FROM AUTHOR]

In this study, nineteen unmodified lignins from various sources (hardwood, softwood, wheat straw, and corn stover) and isolation processes (kraft, soda, organosolv, sulfite, and enzymatic hydrolysis) were used to replace 30 wt.% of petroleum-based polyol in rigid polyurethane/polyisocyanurate (PUR/PIR) foam formulations. Lignin samples were characterized by measuring their ash content, hydroxyl content (Phosphorus Nuclear Magnetic Resonance Spectroscopy), impurities (Inductively Coupled Plasma), and pH. After foam formulation, properties of lignin-based foams were evaluated and compared with a control foam (with no lignin) via cell morphology, closed-cell content, compression strength, apparent density, thermal conductivity, and color analysis. Lignin-based foams passed all measured standard specifications required by ASTM International C1029-15 for type 1 rigid insulation foams, except for three foams. These three foams had poor compressive strengths, significantly larger cell sizes, darker color, lower closed-cell contents, and slower foaming times. The foam made with corn stover enzymatic hydrolysis lignin showed no significant difference from the control foam in terms of compressive strength and outperformed all other lignin-based foams due to its higher aliphatic and p-hydroxyphenyl hydroxyl contents. Lignin-based foams that passed all required performance testing were made with lignins having higher pH, potassium, sodium, calcium, magnesium, and aliphatic/p-hydroxyphenyl hydroxyl group contents than those that failed. [ABSTRACT FROM AUTHOR]

This work reviews the use of carbohydrates and their derivatives as renewable raw materials in the production of surfactants. Methods to attain state‐of‐the‐art carbohydrate‐derived surfactants are described. This includes surfactants widely used nowadays and others that have not yet transcended beyond the academic field. Given the abundance of hydroxyl groups in carbohydrates and the considerable quantity of different surfactant structures that can be generated during their synthesis, selectively obtaining a target product represents a challenge. Therefore, this work focuses on the platform chemicals available to synthesize biobased surfactants. The first part of the review comprises a brief introduction of simple and complex carbohydrates to better understand their chemistry. Then, a description of the processes to obtain biobased building blocks derived from carbohydrates according to the National Renewable Energy Laboratory (NREL, USA), and their usefulness in synthesizing surfactants is presented. This provides an organized inventory of the knowledge around the synthesis–production of surfactants from carbohydrate derivatives, emphasizing raw materials that could be inserted into the circular bioeconomy concept. Finally, the current industry trends and the potential role of biobased surfactants around new dioxane regulations are discussed. [ABSTRACT FROM AUTHOR]

Limiting global warming to 1.5°C requires immediate and drastic reductions in greenhouse gas (GHG) emissions. A significant contributor to anthropogenic global GHG emissions is the production of building materials. Biobased materials offer the potential to reduce such emissions and could be deployed in the short term. Timber construction has received the main attention from policy and industry. However, the implementation of timber construction at the global scale is constrained by the availability of sustainably managed forest supplies. A viable alternative is fast-growing plants and the use of agricultural waste products. These can be deployed faster and are better aligned to local supplies of biomass and demands from the building sector. Fast-growing materials are generally able to achieve net-cooling impacts much faster due to their short rotation periods. The GHG emissions due to the production of biogenic building material can be compensated by regrowth of the new (replacement) plant and, overall, this will absorb CO2 from the atmosphere. A range of biogenic materials can be promoted and used as insulation materials and structural materials. [ABSTRACT FROM AUTHOR]

Surfactants are important chemical products, serving as emulsifiers and interfacial modifiers in the household detergents, personal care products, paints and coatings, foods, cosmetics, and pharmaceuticals industries. This review focuses upon recent advances in research and development to improve the ecological sustainability of surfactants throughout their life cycle, including derivation from renewable resources,production using green manufacturing principles, and improved biocompatibility and biodegradability during their consumer use and disposal stages. Biobased surfactants, derived from vegetable oils, polysaccharides,proteins, phospholipids, and other renewable resources, currently comprise approximately 24% of the surfactant market, and this percentage is expected to increase, especially in Asia. The use of renewables is attractive to consumers because of reduced production of CO2, a greenhouse gas associated with climate change. Enzymes can greatly increase process sustainability, through reduced use of organic solvent, water,and energy, and reduced formation of by-products and waste products. Among the enzymes being investigated for surfactant synthesis, lipases are the most robust, due to their relatively high biocatalytic activity, operational stability and their ability to form or cleave ester, amide, and thioester bonds. For enzymes to be robust catalysts of surfactants, further research and development is needed to improve catalytic productivity, stability and reduce their purchase cost.

This article reports the electrospinning technique for the manufacturing of multilayered scaffolds for bile duct tissue engineering based on an inner layer of polycaprolactone (PCL) and an outer layer either of a copolymer of D,L-lactide and glycolide (PLGA) or a copolymer of L-lactide and ε-caprolactone (PLCL). A study of the degradation properties of separate polymers showed that flat PCL samples exhibited the highest resistance to hydrolysis in comparison with PLGA and PLCL. Irrespective of the liquid-phase nature, no significant mass loss of PCL samples was found in 140 days of incubation. The PLCL- and PLGA-based flat samples were more prone to hydrolysis within the same period of time, which was confirmed by the increased loss of mass and a significant reduction of weight-average molecular mass. The study of the mechanical properties of developed multi-layered tubular scaffolds revealed that their strength in the longitudinal and transverse directions was comparable with the values measured for a decellularized bile duct. The strength of three-layered scaffolds declined significantly because of the active degradation of the outer layer made of PLGA. The strength of scaffolds with the PLCL outer layer deteriorated much less with time, both in the axial (p-value = 0.0016) and radial (p-value = 0.0022) directions. A novel method for assessment of the physiological relevance of synthetic scaffolds was developed and named the phase space approach for assessment of physiological relevance. Two-dimensional phase space (elongation modulus and tensile strength) was used for the assessment and visualization of the physiological relevance of scaffolds for bile duct bioengineering. In conclusion, the design of scaffolds for the creation of physiologically relevant tissue-engineered bile ducts should be based not only on biodegradation properties but also on the biomechanical time-related behavior of various compositions of polymers and copolymers.

A transformation towards a bioeconomy is needed to reduce the environmental impacts and resource requirements of different industries. However, considering the finiteness of land and biomass, such a transition requires strategizing resource and land allocation towards activities that yield maximum environmental benefit. This paper aims to develop a resource-based comparative indicator between economic sectors to enable optimal use of biobased resources. A new methodology is proposed to analyze the climate effectiveness of using straw in the agricultural, energy and construction sectors. For this purpose, avoided and delayed emissions are analyzed for different use cases of straw and then compared. Considering only avoided emissions, the use of straw as a feedstock for bioelectricity has the highest climate effectiveness (930 kg CO _2 eq./t _straw ). Considering only temporal carbon storage, straw-based insulation in buildings has the highest climate effectiveness (881 kg CO _2 eq./t _straw ). Combining avoided and delayed emissions, the use of straw-based insulation has the highest climate effectiveness (1344 kg CO _2 eq./t _straw ). Today EU-Policies incentives the use of straw in the agricultural sector and the energy sector, neglecting the benefit from its use in the construction sector. The results can support policymakers’ trans-sectoral incentives, where agriculture by-products are diverted towards the use of biomass that most boost economic activities and trigger maximum environmental benefit, given the local circumstances.

Lignin is an abundant biobased feedstock, representing the first source of renewable aromatic structures. Thanks to its high functionality in aliphatic hydroxyls (Al-OH), phenolic hydroxyls (Ph-OH) and carboxylic acids (COOH), lignin is an attractive precursor to crosslinked polymer materials. Different biobased macromolecular architectures can be designed from lignins, whose end-of-life should also be considered in the context of a circular bioeconomy. To enhance the recyclability of crosslinked polymer networks, the introduction of dynamic linkages to design vitrimers is a promising strategy. In this study, Kraft lignin was chemically modified with succinic anhydride, to prepare a series of modified lignins with a controlled COOH/Ph-OH ratio, exploiting the difference in reactivity between Al-OH and Ph-OH groups. Upon crosslinking with a diepoxy, mixed vitrimer networks with variable ratios between dynamic ester bonds and non-dynamic ether bonds were synthesized. The analysis of their properties evidenced the impact of the non-dynamic linkages on the materials behaviors, including their dynamicity and reprocessing ability. Although the activation energy for bond exchange is increased, non-dynamic linkages do not hinder the reprocessability of these adaptable materials, and provide them high creep resistance. The controlled introduction of non-dynamic linkages appears as a promising strategy to enhance the properties of lignin-based vitrimers., (© 2024 The Authors. ChemSusChem published by Wiley-VCH GmbH.)

Classic approaches to integrate flexible capacitive sensor performance are to on-demand microstructuring dielectric layers and to adjust dielectric material compositions via the introduction of insoluble carbon additives (to increase sensitivity) or dynamic interactions (to achieve self-healing). However, the sensor's enhanced performances often come with increased material complexity, discouraging its circular economy. Herein, a new intrinsic self-healable, closed-loop recyclable dielectric layer material, a fully nature-derived dynamic covalent poly(disulfide) decorated with rich H bonding and metal-catechol complexations is introduced. The polymer network possesses a mechanically ductile character with an Arrhenius-type temperature-dependent viscoelasticity. The assembled capacitive pressure sensor is able to achieve a sensitivity of up to 9.26 kPa -1 , fast response/recovery time of 32/24 ms, and can deliver consistent signals of continuous consecutive cycles even after being self-healed or closed-loop recycled for real-time detection of human motions. This is expected to be of high interest for current capacitive sensing research to move toward a life-like, high performance, and circular economy direction., (© 2024 Wiley‐VCH GmbH.)

In order to increase their sustainability, antimicrobial renewable molecules are fundamental additions to consumer goods. Rosmarinic acid is extracted from several terrestrial plants and represents an effective anti-microbial agent. Ulvan, extracted from algae, is an anti-microbial polysaccharide. The present review is dedicated to discussing the sources and the extraction methodologies for obtaining rosmarinic acid and ulvan. Moreover, the preparation of bioanosystems, integrating the two molecules with organic or inorganic substrates, are reviewed as methodologies to increase their effectiveness and stability. Finally, the possibility of preparing functional biomaterials and anti-microbial final products is discussed, considering scientific literature. The performed analysis indicated that the production of both molecules is not yet performed with mature industrial technologies. Nevertheless, both molecules could potentially be used in the packaging, biomedical, pharmaceutical, cosmetic, sanitary and personal care sectors, despite some research being required for developing functional materials with specific properties to pave the way for many more applications. [ABSTRACT FROM AUTHOR]

Polyurethanes (PU) are an important class of materials used in various applications across industries. With increased global interest in sustainable and environmentally benign packaging, there is high demand to replace traditional petroleum-based materials with renewable, bio-derived sources. This research developed PU adhesives for multilayer flexible food packaging using Physaria fendleri oil (formerly Lesquerella fendleri) and Ricinus communis (Castor oil), each possessing naturally occurring hydroxyl functional groups. Physaria oil has, on average, hydroxyl functionality on two of the three fatty acids compared to all three for Castor oil; therefore systematically varying the concentration of each oil and maintaining a constant crosslink density for each adhesive facilitates an understanding of the effect of Physaria oil's unreacted hydrocarbon sidechain on physical properties in biobased adhesives. The results of this study determined that the peel resistance of polyethylene and polyethylene terephthalate substrates adhered with adhesives containing varying amounts of Physaria and castor oils possessed average peel strengths of 6–8 N relatively independent of composition. Furthermore, the glass transition temperatures were measured to be within the range of −25 to −44 °C with higher concentrations of the hydrocarbon sidechain resulting in lower Tgs. These physical properties indicate their use in multilayer food packaging adhesive applications where isocyanate PU adhesives are still commonplace. Understanding the PU adhesive network structure-property relationships will help develop the next generation of bio-derived PU adhesives with additional sources of renewable feedstocks for food packaging applications.

Single-use packaging is a major contributor to municipal solid waste and cause of plastic pollution worldwide, whereas the adoption of biodegradable alternatives is still hampered by significant challenges such as performance shortfalls and inadequate barrier properties. The present work utilizes compostable polymers, namely biobased poly(butylene succinate) (BioPBS) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), combined with hybrid natural fillers to achieve enhanced processability and barrier performances for substituting conventional plastic packaging. BioPBS reinforced with 20 wt.% talc showed improved barrier properties over the neat BioPBS, with both the oxygen and water vapor permeabilities improving by about 60%. With the blending of 20 wt.% PHBV, an overall further improvement of about 80% in both properties were achieved. The use of 1% maleic anhydride grafted BioPBS and BioPBS/PHBV-blend coupling agents enhanced the interfacial adhesion of the composites resulting in a consistent improvement of the tensile strength at yield and the oxygen barrier. The incorporation of 5% starch, which could potentially boost the biodegradability of the composites, helped in enhancing the toughness of the material at the expense of lowered barrier properties. Overall, the biocomposites demonstrated comparable mechanical properties to some commodity plastics such as polyolefins while having low oxygen and water permeability, showing great promise for applications in sustainable packaging.

[Display omitted] • Biobased PHFA and PHFSe of the similar composition were synthesized. • The toughness of both PHFA and PHFSe was greatly improved. • The average sequence length of HF was longer in PHFA than in PHFSe. • PHFA crystallized more easily and faster than PHFSe. Two biobased poly(hexamethylene 2,5-furandicarboxylate) (PHF) copolyesters, i.e., poly(hexamethylene 2,5-furandicarboxylate- co -adipate) (PHFA) and poly(hexamethylene 2,5-furandicarboxylate- co -sebacate) (PHFSe) were synthesized in this research by introducing adipic acid (AA) and sebacic acid (SeA) as the comonomers, respectively, with the hexamethylene adipate and hexamethylene sebacate unit contents being almost the same of about 15 mol%. The chemical structures of AA and SeA were similar with a slight difference only in the methylene number, i.e., 4 for AA and 8 for SeA. The influence of different comonomers on the chemical structure, average sequence length, thermal stability, crystal structure, basic thermal parameters, crystallization behavior, and mechanical property of PHF based copolyesters was extensively investigated with various techniques. The average sequence length of hexamethylene 2,5-furandicarboxylate was greater in PHFA than in PHFSe; as a result, PHFA crystallized more easily than PHFSe. The elongation at break of both PHFA and PHFSe were remarkably greater than that of PHF. From a structure and property relationship viewpoint, this study should be of great importance and interest for the research and development of sustainable biobased polymers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dimer acid (DA) prepolyamides (DAPAcs) were synthesized from a diamine and excess DA. • Crosslinked polyβ-hydroxyesters (cPHEs) were prepared from biobased raw materials. • cPHEs were prepared through a ROP polymerization of DAPAcs and a dicyclocarbonate. • The reaction between HOOC– and cyclocarbonate groups forms β-hydroxyester units. • The β-hydroxylester units provided good reprocessability of cPHEs. A new kind of biobased partially crosslinked polyβ-hydroxyesters (cPHEs) was synthesized through the ring-opening polymerization of a five-membered dicyclocarbonate and carboxyl-terminated dimer acid (DA) oligopolyamides (DAPAcs). The DAPAcs provided carboxyl groups and attacked the cyclocarbonate groups to form β-hydroxyester units, which was confirmed by a model reaction. DAPAcs were synthesized from hexamethylenediamine and excess DA. Their structure and properties were confirmed by FTIR, 1H NMR, and DSC. cPHEs exhibited semicrystalline characters with good thermal properties evidenced by wide-angle X-ray scattering, DSC, and TGA. Introducing DAPA sequences improved intermolecular interactions and tensile strength. The attack of pendent hydroxy groups to remaining cyclocarbonate groups led to crosslinked cPHEs. Dynamic β-hydroxylester segments impart the reprocessability of cPHEs, and stress relaxation experiments were conducted at different temperatures to evaluate the exchange kinetics. A new synthetic route different from normal epoxy-carboxyl route was established. This method broadens the research of polyβ-hydroxylesters and their application range. [ABSTRACT FROM AUTHOR]

Synthesized a novel bio-based polyester from 2,5-furandicarboxylic acid and citric acid with excellent mechanical and gas barrier properties. [Display omitted] • New bio-based polyesters from furandicarboxylic acid. • Excellent mechanical properties. • Good gas barrier properties. • Applied as packaging materials. Biobased feedstocks developed from renewable resources play a crucial role in polymers. Dimethyl octahydro-2,5-pentalenediol (MeOPD) with excellent thermal stability and rigidity is a biobased bicyclic diol derived from citric acid. In this work, MeOPD was first reacted with dimethyl carbonate (DMC) to form oligo (dimethyl octahydro-2,5-pentalenediol carbonate) (OMC). Subsequently, a series of poly(butylene-co-dimethyl octahydro-2,5-pentalenediol furanoate-co-carbonate) (PBMFC) polyesters with MeOPD units ranging from 5 to 31 mol% were synthesized via melt polycondensation from OMC, dimethyl furan-2,5-dicarboxylate (DMFD) and 1,4-butanediol (BDO). Due to the low reactivity of MeOPD, its actual content in copolymer is much lower than that in the feed, and as the MeOPD content rises, the number-average molecular weight of PBMFCs drops from 25,200 g/mol of PBMFC5 to 12,800 g/mol of PBMFC31. Despite the presence of MC units weakens thermal stability, PBMFCs still maintain good thermal stability, evidenced by T d,5% ranging from 294-325 °C in N 2 and from 295-339 °C in air. The mechanical properties are also satisfactory, exhibiting tensile modulus ≥ 500 MPa, tensile strength ≥ 23 MPa, and elongation at break ≥ 150 %. Compared to PET, PBMFCs demonstrate commendable gas barrier properties, with CO 2 and O 2 barrier capability being 4.7–11.0 times and 2.0–3.6 times that of PET, respectively. All results indicate that PBMFCs can serve as a renewable potential material for packaging application. [ABSTRACT FROM AUTHOR]

The inclusion of hazardous substances in the formulation of plastics raises significant concerns, particularly, if those substances are released as primary leachates during plastic degradation and/or fragmentation. In this sense, the production of degradable plastics holding deleterious additives can increase the release of harmful substances into the environment. Additionally, the effects of primary leachates of "eco-friendly" materials remain unexplored. To address this, we performed exposures to primary leachates of alternative polymers, and commercial bags to verify possible responses associated with endocrine disruption and/or activation of the detoxification pathway in larvae of the marine fish model Cyprinodon variegatus. The chemical characterization evidenced a great number of additives in the formulation of the materials analyzed in this study. Those include, except for the PLA sample, relevant levels of the hazardous phthalates DEHP and DiBP. Regarding the effects on marine fish larvae, exposure to leachates from alternative polymers (10 g/L) PHB and PHBV produced remarkable mortality (100%). While the exposure to bag leachates of all tested materials (1 and 10 g/L) produced alterations in biomarkers for steroidogenic and detoxification pathways. To a lesser extent (10 g/L), three materials produced significant alterations in estrogenic biomarkers (Home-compostable bag 1, LDPE and Recycled PE bags). Although the alterations in gene expression were not directly correlated to the amount of DEHP or DiBP, we can conclude that primary leachates of "eco-friendly" bags are harmful to marine vertebrates. [Display omitted] • Quantifiable levels of DEHP and DiBP can be found in resins, conventional and alternative bags. • Primary leachates of plastic bags modulate the expression of estrogenic and steroidogenic genes. • Alterations in gene expression are not proportionally linked to the quantity of DEHP or DiBP. • Commercial bags primary leachates promote the activation of detoxification pathway in fish larvae. [ABSTRACT FROM AUTHOR]

A novel phosphorous-containing acrylated epoxidized soybean oil-based (P-AESO) resin was developed via the ring-opening reaction of epoxidized soybean oil (ESO) with diphenylphosphinic chloride (DPPC), followed by acrylation of the resulting groups. The chemical structure was characterized by Fourier transform infrared spectroscopy (FT-IR), and 1H nuclear magnetic resonance (1H NMR). Subsequently, the viscosity and volumetric shrinkage of the obtained P-AESO resins were studied. Then the oligomer was formulated into UV-curable coatings, and the mechanical, thermal, and coating properties of the resulting UV-cured bioresins were studied by tensile testing, dynamic mechanical thermal analysis (DMA), thermogravimetric analysis (TGA) coupled with FT-IR spectroscopy (TGA-FT-IR), hardness, adhesion, pencil hardness and chemical resistance. Furthermore, the UV-curing behavior of the P-AESO resin was determined by real-time realtime infrared (RT-IR). Meanwhile, compared with coating from acrylated epoxidized soybean oil (AESO), the P-AESO system coatings showed better volumetric shrinkage, excellent adhesion, and enhanced thermal and glass transition temperature (Tg) while maintaining reasonably final C=C conversions and cross-link density. For instance, the obtained P-AESO/trimethylolpropanetriacrylate (TMPTA) 20 material possessed a volumetric shrinkage of 4.1%, Tg of 115.6°C, char yield of 9.47%, and final C=C conversions of 81.4% respectively, which exhibited superior values than that of the AESO/TMPTA20 material. The improvement of the P-AESO coating performances could contribute to the architectures that combined the structural features of phosphorous-containing rigid benzene. The developed P-AESO resin is promising for applications in the UV-curable coatings.

The increasing energy demand in conjunction with greater environmental concern has lifted the development of sustainable energy sources, including materials for energy storage. The use of phase change materials (PCM) for thermal energy storage (TES) has become one of the emerging research fields. Paraffins are currently the most studied organic PCMs for TES applications due to their favorable physical and thermal properties. However, they are produced from non-renewable sources and their carbon footprint and associated environmental impact cannot be overlooked. A green alternative are the biobased PCMs such as fatty acid esters andfatty acids. The present paper reviews the current research status of biobased PCMs with focus on various limitations and drawbacks, and on strategies adopted for improving their TES characteristics. The paper also discusses the use of waste biomaterials such as waste cooking oil and non-edible plant oils as potential alternatives to edible oil based PCMs. Novel strategies which could serve as a cornerstone for further research on new biobased PCMs for the future, are also discussed.

Food packaging has a crucial function in the modern food industry. New food packaging technologies seek to meet consumers and industrial's demands. Changes related to food production, sale practices and consumers' lifestyles, along with environmental awareness and the advance in new areas of knowledge (such as nanotechnology or biotechnology), act as driving forces to develop smart packages that can extend food shelf-life, keeping and supervising their innocuousness and quality and also taking care of the environment. This review describes the main concepts and types of active and intelligent food packaging, focusing on recent progress and new trends using biodegradable and biobased polymers. Numerous studies show the great possibilities of these materials. Future research needs to focus on some important aspects such as possibilities to scale-up, costs, regulatory aspects, and consumers' acceptance, to make these systems commercially viable.

A series of bio‐rubber (BR) tougheners for thermosetting epoxy resins was prepared by grafting renewable fatty acids with different chain lengths onto epoxidized soybean oil at varying molar ratios. BR‐toughened samples were prepared by blending BRs with diglycidyl ether of bisphenol A resins, Epon 828 and Epon 1001F, at different weight fractions and stoichiometrically cured using an amine curing agent, 4, 4′‐methylene biscyclohexanamine (PACM). Fracture toughness properties of the unmodified and BR toughened polymer samples—including critical strain energy release rate (GIc), and critical stress intensity factor (KIc)—were measured to investigate the toughening effect of prepared BRs. It was found that the degree of phase separation and toughening were more controllable relative to similar polymers cured using the aromatic curing agent Epikure W, and the use of higher molecular epoxy resins produces a synergistic effect increasing the toughness much more than similar polymers made with lower molecular weight epoxy resins. Average BR domain sizes ranging from 200 to 900 nm were observed, and formulations with GIc, values KIc as high as 1.0 kJ/m2 and 1.4 MPa m1/2 were attained respectively for epoxy systems with Tg greater than 130°C. [ABSTRACT FROM AUTHOR]

A series of bio‐rubber (BR) reactive tougheners for thermosetting epoxy resins was prepared by grafting renewable saturated fatty acids of different chain lengths (C6‐C14) onto epoxidized soybean oil (ESO) at varying molar ratios. The tunable nature of the BR systems derives from the architecture and functionality of naturally occurring molecules. Control of BR reactivity and molecular weight by varying the degree of grafting and the chain length of the fatty acid was demonstrated. The BR‐toughened samples were prepared by blending BRs with diglycidyl ether of bisphenol A (DGEBA), Epon 828, and stoichiometrically curing the mixture using an aromatic amine hardener, diethyl toluene diamine (Epikure W). Fracture surface morphology studies showed that tuning of phase separated particle sizes was possible depending on the BR type and weight fraction. The resulting toughening effect was evaluated by measuring the fracture toughness of control and toughened polymer samples. The use of BRs significantly improved the critical strain energy release rate and critical stress intensity factor values of thermosetting polymer samples without significantly reducing Tg and modulus. In addition to toughening and adding renewable content to petroleum‐based thermosetting epoxy systems these new tougheners have low viscosity compared to common alternatives and aid ease of processing. [ABSTRACT FROM AUTHOR]

A study was carried out to compare the epoxidation of unsaturated vegetable oils using dioxirane intermediates generated in situ using Oxone to that by the peracid/hydrogen peroxide method. Epoxidized oils are typically synthesized using hydrogen peroxide, as well as acetic or formic acid. This synthesis requires heating and catalysts and generates acidic waste. Recently, advances have been made in the process of using Oxone (potassium peroxymonosulfate) and ketones to generate in situ dioxiranes to epoxidize alkenes. The dioxirane method allows for room temperature reactions and eliminates the use of peroxides and acids. Epoxidation of soybean oil, hempseed oil and sucrose soyate using in situ generated dioxiranes was carried out and parameters such as molar ratios and addition rates were studied. The data show that optimum reaction conditions are reached when molar ratios of Oxone and unsaturation are 1.6:1 and the Oxone addition rate is 1 mL min–1. As a comparison, epoxidations using the acetic acid/hydrogen peroxide method were carried out and cured materials were prepared from the epoxidized compounds. Negligible differences were identified in the materials prepared from both synthetic pathways. An environmental sustainability assessment using green chemistry principles was also conducted for both methods to evaluate their safety and efficiency with respect to multiple criteria including minimizing waste generation and energy consumption. The analysis shows that, although the peracid method is atom economic and generates less waste, the dioxirane method offers better occupational safety and requires less energy, demonstrating the tradeoffs involved with either pathway if one is to be selected. © 2021 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

New semi‐aromatic bio‐based copolyamides PA 4T/4Y and PA 6T/6Y were successfully synthesized in bulk by direct solid‐state polycondensation in which hydrophobic bio‐based dicarboxylic acids sebacic acid, octadecanedioic or hydrogenated dimer fatty acid (Y = C10, C18 or C36) alternate with terephthalic acid T. The absence of a polymerization solvent and the possibility of performing the polymerization on the dicarboxylic acid make it an interesting route for future production of alternating copolyamides. A stepwise synthetic approach is taken where first terephthalic acid‐based diamide diamines of the linear C4 or C6 diamines 4T4 or 6T6 are prepared, followed by preparation of solid salts with the above aliphatic dicarboxylic acids and subjecting the salts to a solid‐state post‐condensation. The alternation is achieved by the interlocking of the 4T4 or 6T6 units in the salts with the bio‐based dicarboxylic acids and polymerizing these salts below the melt temperature of the terephthalamide‐based core. During the polycondensation, the transamidation reaction of the terephthalamide moiety is prevented and with that the randomization of the polyamide. Especially the diaminobutane‐based PA 4T/4Y copolyamides show strict alternation, leading to interesting properties like high crystallinity and high melting points of 250 to 318 °C supported by a randomness value of 2, determined using13C NMR spectroscopy. The special alternating feature becomes especially clear when heating the polymer in the melt state, when the transamidation of the terephthalamide moieties is no longer prevented by the interlocking principle, leading to lowering of the randomness value and therewith the melting point and crystallinity. © 2020 Society of Industrial Chemistry [ABSTRACT FROM AUTHOR]

Manufactured biobased mulch (biomulch) films and fabrics are useful non-chemical weed management tools, but are not typically used for high-density plantings of vegetables such as lettuce (Lactuca sativa L.) and carrot (Daucus carota L. subsp. sativus). However, it may be possible for crop roots to grow through a permeable biomulch membrane. Our objective was to demonstrate the potential for lettuce and carrot to germinate on and grow through biomulch, and assess changes in crop growth and yield. Biomulches included a 100% polylactic acid (PLA) biofabric and a PLA (37%) + soybean meal (63%) biofabric (PLA + SOY). Seeds were placed directly on biomulch and top-dressed with a soil mix or compost. Crop roots grew through the biomulch (despite visible constriction in carrot), and total yields were either the same or greater than those in the no-mulch control. PLA + SOY increased lettuce yield by 72% and also degraded faster than the PLA mulch. Results hold promise for improving weed control and reducing labor in high-density vegetable plantings. [ABSTRACT FROM AUTHOR]

In this study, nineteen unmodified lignins from various sources (hardwood, softwood, wheat straw, and corn stover) and isolation processes (kraft, soda, organosolv, sulfite, and enzymatic hydrolysis) were used to replace 30 wt.% of petroleum-based polyol in rigid polyurethane/polyisocyanurate (PUR/PIR) foam formulations. Lignin samples were characterized by measuring their ash content, hydroxyl content (Phosphorus Nuclear Magnetic Resonance Spectroscopy), impurities (Inductively Coupled Plasma), and pH. After foam formulation, properties of lignin-based foams were evaluated and compared with a control foam (with no lignin) via cell morphology, closed-cell content, compression strength, apparent density, thermal conductivity, and color analysis. Lignin-based foams passed all measured standard specifications required by ASTM International C1029-15 for type 1 rigid insulation foams, except for three foams. These three foams had poor compressive strengths, significantly larger cell sizes, darker color, lower closed-cell contents, and slower foaming times. The foam made with corn stover enzymatic hydrolysis lignin showed no significant difference from the control foam in terms of compressive strength and outperformed all other lignin-based foams due to its higher aliphatic and p-hydroxyphenyl hydroxyl contents. Lignin-based foams that passed all required performance testing were made with lignins having higher pH, potassium, sodium, calcium, magnesium, and aliphatic/p-hydroxyphenyl hydroxyl group contents than those that failed.

Generally, the coating properties of polymeric compounds are enhanced by using nanomaterials as fillers which are non-biobased. In this project, the hydroxyapatite (HAP) was obtained from waste fish scales and the biobased hyperbranched polyol (HyBP) was synthesized from castor oil. The series of nanocomposites were prepared by adding various amounts of HAP (0.5% wt, 1% wt, and 2% wt) in HyBP along with isophorone diisocyanate (IPDI) (maintaining the NCO:OH, ratio at 1.2:1). These mixtures were coated on mild steel panels and glass plates. The synthesized HyBP was characterized by FTIR, 1HNMR, and 13CNMR techniques. The HAP was characterized by FTIR, FESEM, and XRD techniques. The surface morphology of prepared nanocomposites was studied by FESEM, XRD, and AFM techniques. The nanoparticle size was determined by TEM technique. The thermal behavior of nanocomposites was studied by TGA technique. The coating properties were determined by impact strength, crosscut adhesion, and flexibility test. The corrosion properties of the coatings were determined by the immersion test as well as electrochemical test. [ABSTRACT FROM AUTHOR]

A simple and green method was established to prepare self‐healing cross‐linked nonisocyanate polyurethanes (SH‐cNIPUs) from biobased diglycerol bis(cyclic carbonate) (DGDC). Two nonisocyanate polyurethane prepolymers with furan terminal groups (tFU‐NIPUs) were synthesized through a ring‐opening reaction of DGDC with furan methylamine and trimethylolpropane tris(poly[propylene glycol], amine terminated) ether, or tris(2‐aminoethyl) amine under mild conditions. The SH‐cNIPUs were prepared via a Diels–Alder reaction between tFU‐NIPUs and a bismaleimide. SH‐cNIPUs were characterized by ATI‐FTIR, 1H NMR, differential scanning calorimetry, polarized optical microscope, and tensile strength after being damaged and healed. SH‐cNIPUs with glass transition temperature from 8 to 49°C, tensile strength up to 21 MPa, and self‐healing efficiency from 67 to 80% were successfully synthesized. [ABSTRACT FROM AUTHOR]

By the end of 1980s, for the first time polyhydroxyalkanoate (PHA) copolymers with incorporated 4-hydroxybutyrate (4HB) units were produced in the bacterium Cupriavidus necator (formally Ralstonia eutropha) from structurally related carbon sources. After that, production of PHA copolymers composed of 3-hydroxybutyrate (3HB) and 4HB [P(3HB-co-4HB)] was demonstrated in diverse wild-type bacteria. The P4HB homopolymer, however, was hardly synthesized because existing bacterial metabolism on 4HB precursors also generate and incorporate 3HB. The resulting material assumes the properties of thermoplastics and elastomers depending on the 4HB fraction in the copolyester. Given the fact that P4HB is biodegradable and yield 4HB, which is a normal compound in the human body and proven to be biocompatible, P4HB has become a prospective material for medical applications, which is the only FDA approved PHA for medical applications since 2007. Different from other materials used in similar applications, high molecular weight P4HB cannot be produced via chemical synthesis. Thus, aiming at the commercial production of this type of PHA, genetic engineering was extensively applied resulting in various production strains, with the ability to convert unrelated carbon sources (e.g., sugars) to 4HB, and capable of producing homopolymeric P4HB. In 2001, Metabolix Inc. filed a patent concerning genetically modified and stable organisms, e.g., Escherichia coli, producing P4HB and copolymers from inexpensive carbon sources. The patent is currently hold by Tepha Inc., the only worldwide producer of commercial P4HB. To date, numerous patents on various applications of P4HB in the medical field have been filed. This review will comprehensively cover the historical evolution and the most recent publications on P4HB biosynthesis, material properties, and industrial and medical applications. Finally, perspectives for the research and commercialization of P4HB will be presented.

Surfactants are crystallizing a certain focus for consumer interest, and their market is still expected to grow by 4 to 5% each year. Most of the time these surfactants are of petroleum origin and are not often biodegradable. Cashew Nut Shell Liquid (CNSL) is a promising non-edible renewable resource, directly extracted from the shell of the cashew nut. The interesting structure of CNSL and its components (cardanol, anacardic acid and cardol) lead to the synthesis of biobased surfactants. Indeed, non-ionic, anionic, cationic and zwitterionic surfactants based on CNSL have been reported in the literature. Even now, CNSL is absent or barely mentioned in specialized review or chapters talking about synthetic biobased surfactants. Thus, this review focuses on CNSL as a building block for the synthesis of surfactants. In the first part, it describes and criticizes the synthesis of molecules and in the second part, it compares the efficiency and the properties (CMC, surface tension, kraft temperature, biodegradability) of the obtained products with each other and with commercial ones.

This review deals with the evolution of bio-based packaging and the emergence of various nanotechnologies for primary food packaging. The end-of life issues of packaging is discussed and particularly the environmental problems associated with microplastics in the marine environment, which serve as a vector for the assimilation of persistent organic pollutants in the oceans and are transported into the food chain via marine and wild life. The use of biodegradable polymers has been a primary route to alleviate these environmental problems, but for various reasons the market has not developed at a sufficient pace that would cope with the mentioned environmental issues. Currently, the biodegradable plastics only constitute a small fraction of the fossil-based plastic market. Fossil-based plastics are, however, indispensable for food safety and minimization of food waste, and are not only cheap, but has generally more suitable mechanical and barrier properties compared to biodegradable polymers. More recently, various nanotechnologies such as the use of nanoclays, nanocellulose, layer-by-layer technologies and polyelectrolyte complexes have emerged as viable technologies to make oxygen and water vapor barriers suitable for food packaging. These technological developments are highlighted as well as issues like biodegradation, recycling, legislation issues and safety and toxicity of these nanotechnologies. [ABSTRACT FROM AUTHOR]

The use of sustainable hybrid components is an important topic in lightweight automotive applications. Wood being a renewable material, when used in combination with other materials such as technical polymers, offers a high potential for producing hybrid components and the implementation of innovative lightweight automotive materials. The feasibility of wood-based hybrid automotive components strongly depends on the properties of the interface between wood, lignin as a renewable coupling agent, and technical polymers. This paper investigates the macromolecular reactions and the bonding area in biobased epoxy adhesives for a specific influence on the performance of structural automotive wood components. Therefore, a typical bisphenol A diglycidyl ether epoxy adhesive was modified with lignosulphonate to increase the penetration depth. The composites were characterized by thermogravimetric analysis coupled with Fourier-transform infrared spectroscopy to validate the crosslinking of the macromolecules and the thermal stability of the adhesive. In the next step, a layer-by-layer composite was built up with the biobased adhesive and 1 mm beech veneer. The bonding area was characterized by scanning electron microscopy and compression tests. [ABSTRACT FROM AUTHOR]

The transition towards a biobased economy requires innovations. In addition to the usual challenges of innovation trajectories, the characteristics of biobased innovations cause extra difficulties. To lower the failure rate of innovation trajectories in general, companies tend to form R&D collaborations. Choices made during the formation of such R&D collaborations play a key role in the project's success. Here, one may benefit from the social sciences. This paper presents a perspective on what the social sciences may bring to analyze and improve the formation process of biobased R&D collaborations. The paper also provides an overview of relevant innovation and transition models, and lists the dominant variables in such formation processes (biobased characteristics and general determinants), and the guidelines that seem useful. Although each model has its advantages, none of the innovation and transition models studied addresses both the phases of a formation process of a biobased R&D collaboration and the variables involved in each phase. Concerning the formation process of biobased R&D collaborations, the literature addresses social, organizational, technological, economic, and environmental variables. The key determinants of multi‐partner R&D collaborations are partner properties, motives to join a consortium, appropriability of a firm, and project properties. The descriptions of their influence on an R&D collaboration presented here can be used as guidelines, as recommendations, in processes for the formation of relatively less complex R&D collaborations. The influence of biobased characteristics – such as type of innovation (drop‐ins versus novel materials), biorefinery, biomass supply and technological challenges – on R&D collaboration have not been studied systematically as yet. © 2020 The Authors. Biofuels, Bioproducts, and Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Novel malonate-functional polyesters from biobased and potentially biobased monomers were developed and cured through the base-catalyzed carbon-Michael addition reaction with acryloyl-functional oligomers. Both drop-in monomers, such as fully biobased diethyl malonate, and alternative raw materials, such as isosorbide and vegetable oil, were introduced. Isosorbide-based polyesters show improved performance to humidity in terms of adhesion on epoxy-amine primer, while vegetable oil-containing resins lead to improved coating appearance due to better flow and levelling. This study demonstrates that biobased malonate resins, having renewable contents up to 53%, offer attractive performance benefits in 2K RMA paints. It is anticipated that, with the development of additional fully biobased polyols, renewable contents in excess of 80% can be achieved. [ABSTRACT FROM AUTHOR]

In this work three biobased epoxy monomers derived from nopol were successfully prepared. Different strategies were employed to synthesize the monomers, such as alkylation of nopol with epichlorohydrin, nucleophilic aromatic substitution using the alkoxide of nopol and cyanuric chloride, and acetalization of nopol with 3-cyclohexene 1-carboxyaldehyde. All unsaturated intermediates were subsequently epoxidized using dimethyl dioxirane as the oxidizing agent. The kinetics of photopolymerization demonstrated that the three synthesized epoxy monomers exhibited high reactivity due to the highly strained epoxy group situated in the already highly strained bicyclic structure of nopol. The glass transition temperatures determined by Differential Scanning Calorimetry (DSC) were 66 °C and 60 °C for the trifunctional monomers 2, 4, 6-tris (2-(7, 7-dimethyl-3-oxatricyclo [4.1.1.0 2,4] octan-2-yl) ethoxy)- 1, 3, 5-triazine (N2) and 2,2′-(((7-oxabicyclo [4.1.0] heptan-3-yl methylene) bis (oxy)) bis (ethane-2,1-diyl)) bis (7, 7-dimethyl-3-oxatricyclo [4.1.1.02,4] octane) (N3) respectively, and of 12 °C for bifunctional monomer 7, 7-dimethyl-2- (2-(oxiran-2-yl-methoxy) ethyl)-3-oxatricyclo [4.1.1.0 2,4] octane (N1). The aromatic triazine epoxy monomer N2 displayed the highest thermal stability in comparison with the other two monomers, with an onset of degradation of 302 °C as determined by the Thermogravimetric Analysis (TGA). [ABSTRACT FROM AUTHOR]

A series of environmentally friendly polyamides (PA69, PA109 and PA129) have been synthesized by carrying out step-melting polycondensation reactions of bioderived monomers: 1,9-azelaic acid with different chain length diamines, respectively. Their molecular structure and chemical composition have been characterized using elemental analysis (EA), Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy. Their crystal structures, mechanical properties, thermal behaviors and moisture absorption properties have also been investigated. The number-average molecular weights of PA69, PA109 and PA129 were 51,300, 38,900 and 38,500, respectively, and the main crystal structures of them were α-crystalline and γ-crystalline form. As the length of diamine increased, the melting temperatures of them were from 214 to 203 to 195 °C, respectively, and the crystallization temperatures of them were from 176 to 166 to 161 °C, respectively. The bending strengths of them were determined to be 102.58 MPa, 84.11 MPa, 65.91 MPa, respectively, and the izod impact strengths of them were 9.24 kJ/m2, 8.82 kJ/m2, 8.54 kJ/m2, respectively. They were also found to absorb less moisture than PA6 and PA66. [ABSTRACT FROM AUTHOR]