Search

In order to compare the effect of the monophenyl ring terephthalic acid (TPA) and biphenyl rings 4,4′‐oxybisbenzoic acid (OBBA) with ether bond on poly(butylene adipate) (PBA)‐based copolyesters properties, two copolyester series poly(butylene adipate‐co‐butylene terephthalate)s (PBATs) and poly(butylene adipate‐co‐butylene oxybisbenzoate)s (PBAOs) were synthesized, and comparatively investigated. All the synthesized copolyesters had satisfactory number‐average molecular weights in the range of 26,500–73,000 g/mol. For PBATs copolyesters, the crystalline structure gradually transitioned from the monoclinic crystal structure of poly(butylene adipate) to poly(butylene terephthalate) (PBT) with increasing TPA because of the crystalline segments transformation from butylene adipate to butylene terephthalate, while PBAO copolyesters progressively shifted from the crystalline structure of PBA to the amorphous structure of poly(butylene oxybisbenzoate) (PBO) as increasing content of OBBA. The incorporation of either TPA or OBBA comonomers with rigid cyclic structure into PBA chain noticeably increased the glass transition temperature (Tg). With the same monomer molar ratio, PBAOs because of incorporation of the bicyclic comonomers presented higher Tg (range from −24.2 to 49.5°C) than that of PBATs (range from −56.5 to 22.4°C). It was found that copolyesters with bicyclic and ether bond OBBA comonomers exhibited a better flexibility in property than that with monocyclic TPA comonomers. [ABSTRACT FROM AUTHOR]

Poly(butylene succinate) (PBS)/poly(ethylene brassylate) (PEB) biodegradable polyester blends were prepared at different PEB contents (5 to 30 wt%) to study the influence of the addition of PEB on the rheological behavior, morphology, thermal and mechanical properties of the blends. A gradual decrease in the shear viscosities and a greater shear thinning behavior were observed with increasing PEB content due to its low molecular weight, which acted as a lubricant or plasticizer, favoring the disentanglement of PBS chains. The blends with higher PEB content (25 and 30 wt%) had higher activation energy values and were more sensitive to temperature variations. The morphology showed good dispersion of PEB in the PBS matrix. Still, increased PEB content led to larger droplets, indicating immiscibility and poor adhesion between phases. PEB influenced both nucleation density and spherulite size of PBS/PEB blends, denoted by an increasing degree of crystallinity, a shift to low crystallization temperatures, and an improvement in the decomposition temperature according to their thermal properties. Low PEB contents (5 and 10%) increased PBS toughness due to the higher crystalline fraction and smaller crystal size of these blends. [ABSTRACT FROM AUTHOR]

The effect of incorporating different percentages of hydrophobic and hydrophilic nanosilica (HPB and HPL NS) particles and chain extender (CE) on the mechanical behavior of poly(lactic acid)/poly(butylene adipate‐co‐terephthalate) (PLA/PBAT) blends was evaluated. The mechanical behavior of the samples was explained using different theoretical models. Microscopic studies showed that adding both types of NS particles and CE led to more uneven surfaces for blends. Also, no obvious aggregations were observed in both blend nanocomposites, and both kinds of NS particles were mainly present in the PBAT phase. Except for the blend containing 1 phr HPB NS particles, which revealed a continuous morphology, all the PLA/PBAT blends containing both types of NS particles indicated a droplet‐matrix morphology. The more the NS content, the more uniform the PBAT distribution. Adding CE in the blends improved Young's modulus, yield strength, and elongation‐at‐break to a particular loading of CE (2 phr), while these properties were diminished after introducing more CE. Also, the most improvements in the yield strength (45%) and Young's modulus (35%) were seen for the PLA/PBAT (75/25 w/w) containing 2 phr CE and 5 phr HPL NS particles. Besides, a good agreement was observed for experimental values and theoretical models for all samples. [ABSTRACT FROM AUTHOR]

Poly(lactide)/poly(butylene adipate‐co‐terephthalate) (PLA/PBAT) blends containing different amounts of polyethylene wax (PEW) were fabricated via melt‐blending, and the effects of PEW on the interfacial morphological evolution and properties of the PLA/PBAT blends were investigated. Scanning electron microscopy (SEM) micrographs show that the compatibility between PLA and PBAT is obviously improved by addition of low contents of PEW. Differential scanning calorimeter (DSC) results indicate that PEW can simultaneously enhance the crystallization ability of PLA and PBAT. Rheological behavior of the blends indicates that PEW has a significant plasticizing effect and can promote the mobility of polymer chains in the blends. More importantly, it is revealed that PEW can effectively improve the mechanical and barrier properties of the blends. Even with a PEW content of only 1 wt%, the elongation at break and notched impact strength of the blend reach 344.1% and 12.55 kJ/m2, respectively, which are 54% and 140% higher than the blend without PEW. Meanwhile, the water vapor transmission rate (WVTR) and oxygen transmission rate (OTR) of the films containing 1 wt% PEW are decreased from 87.34 to 67.40 g m−2·24 h−1 and from 118.26 to 80.94 cm3 m−2·24 h−1, respectively, which are 22.8% and 31.5% lower than those of the PLA/PBAT film. [ABSTRACT FROM AUTHOR]

The Lewis acidic framework Ti sites in Ti-Beta and Si-Beta catalysts were compared by FT-IR and NMR characterization methods before they were applied to the conversion of four butenes. The results showed that Si-Beta has fewer Lewis acid sites and abundant weak Brønsted acidic silanol nests, which play an important role in conversions between n-butene, cis-2-butene, and trans-2-butene. The conversions for these butenes over Si-Beta were always higher than those over a series of Ti-Beta catalysts with gradient-varied Lewis acidic framework Ti sites and silanols. This is because isobutene can only oligomerize, which requires stronger acidity, so its conversion over Si-Beta was lower than those over Ti-Beta zeolites. For a series of Ti-Beta catalysts with different abundances of Lewis acidic Ti sites, the more Lewis acid sites it had, the higher the conversions for the four butenes. [ABSTRACT FROM AUTHOR]

In order to overcome the drawback of poor mechanical and rheological properties and potentially extend the poly(butylene adipate-co-butylene terephthalate) (PBAT) application market, in this work, we developed PBAT blend with excellent comprehensive performance through blending with biodegradable poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA). Two-step melt blending and constant polylactide (PLA) content were devised to prepared PBAT blend. The effect of PDLA on the crystallization properties, rheological properties, miscibility, morphological structure, and mechanical properties of blend was investigated. According to torque-time curve and DSC results, PLA stereocomplex (SC-PLA) crystallites were formed in blend system. DMA results confirmed that the compatibility between PBAT and PLLA was not changed when PDLA was introduced. SEM results showed that the phase morphology of PBAT/20PLLA/0PDLA blend displayed typical sea-island structure and the particle size of dispersed phase decreased accompanying by agglomeration when PDLA was added. Rheological results showed that percolation SC-PLA network structure had formed and a much denser crystallite network could be formed with high PDLA content, which significantly enhanced rheological properties of blend. The mechanical results demonstrated that the addition of PDLA could significantly enhance mechanical properties. The blend with 6 wt% PDLA presented yield strength, elongation at break, and modulus about 13.3 MPa, 307%, and 221.2 MPa, respectively, the yield strength and modulus increased by 141.7% and 54.7% compared with the pure PBAT. [ABSTRACT FROM AUTHOR]

Poly(butylene succinate) (PBS), a biodegradable material, has excellent mechanical properties and processing properties. Brassylic acid (BA) is a kind of diacid with long chains derived from biomass. In this study, poly(butylene succinate-co-butylene brassylate) is synthesized to investigate the effects of BA on the structure and properties of PBS. The relationship between the melting temperature of copolyesters and the content of butylene brassylate units is V-shaped, which is typical of isodimorphic random copolyesters. Due to the introduction of BA, the density of unstable ester bonds in copolyesters gradually decreases and the initial thermal decomposition temperature of copolyesters gradually increases with the increase of BA. The dynamic mechanical analysis showed that the glass transition temperature of PBS was reduced by the introduction of BA. When the BA content is 25%, the copolyesters and PBS have the same crystal structure. When the BA content is 50–100%, the copolyesters and poly(butylene brassylate) have the same crystal structure, which indicates that the butylene brassylate units are easier to crystallize than the butylene succinate units. The ductility of copolyesters increases with the addition of BA. When the BA content is 50%, the elongation at break reaches the maximum (> 2000%). The copolyesters are suited for films due to high elongation at break. [ABSTRACT FROM AUTHOR]

With the issue of plastic waste persisting and the need for more sustainable solutions to the ever‐increasing demand for lightweight and durable plastic products, this review has become imminent and compelling. Poly (butylene adipate‐co‐terephthalate) (PBAT) is a biodegradable polymer with exceptional film‐forming ability resembling those of low‐density polyethylene. PBAT has a huge advantage for packaging applications due to its remarkably high elongation at break, giving it a good processing window for its application in packaging. However, certain defiant intrinsic properties stand in the way of its full commercialization. The development of blends and biocomposites of PBAT has, therefore, become imperative for complementing its properties and producing a superior material. This paper focuses on the recent developments in preparing PBAT‐based blends and biocomposites with superior mechanical, barrier, and antimicrobial properties and, most importantly, has also investigated how the development of these blends and biocomposites impacts the biodegradation rate of PBAT. It also highlights the possible synthesis of bio‐based PBAT and the commercialization, market trends, and prospects of PBAT‐based materials for flexible, rigid packaging, and other industrial applications compared with biodegradable alternatives. [ABSTRACT FROM AUTHOR]

The application range of biodegradable Poly(butylene succinate) (PBS) is highly dependent on its mechanical properties, which can be improved by the annealing process. In this study, the mechanical properties and microstructure of PBS films with oriented lamellar structures annealed at different temperatures were characterized. It was found that the annealing process effectively improves the elastic modulus and yield strength of the oriented PBS film with the increase of annealing temperature, which is completely different from the previous results of other oriented semicrystalline polymers such as PP, PMP, PE, and PVDF. The long periods, lateral dimensions and orientation of the lamellae of the oriented PBS film increase with the increasing annealing temperature. Meanwhile, the low‐temperature endothermic plateau in the DSC curve and the g1,r/Q in the SAXS experiment decrease with annealing temperature, indicating that increasing annealing temperature would reduce the thin and metastable lamellae in the PBS films. Compared the annealing results of oriented PBS films and that of other‐oriented semicrystalline polymers, we suggested the annealing process for the oriented PBS films would reduce the thin lamellae and form thicker lamellae, resulting in an increase in the elastic modulus and yield strength of the annealed PBS films. This study clarifies how the annealing temperature affects the microstructure and mechanical properties of the oriented semicrystalline films. [ABSTRACT FROM AUTHOR]

Mesoporous HZSM-5 zeolites with nanocrystal stacking morphology were directly synthesized via hydrothermal methods without mesoporous templates. The synthesized mesoporous HZSM-5 was subjected to hydrothermal–citric acid washing treatment. The structural and acidic properties of the samples before and after modification were characterized using various techniques. The catalytic performance for butene conversion to propylene was investigated under atmospheric pressure, 500 °C, and a butene weight hourly space velocity (WHSV) of 10 h−1 in a continuous-flow micro-fixed bed reactor. The results show that propylene selectivity increased significantly from 24.7% before modification to 44%, and propylene yield increased from 22% to 38%. After 2 h of hydrothermal–citric acid washing modification, the catalyst maintained a butene conversion rate of 76% and a selectivity of 47% at 525 °C and a WHSV of 10 h−1 after 130 h of continuous reaction, with a propylene yield of 37%. The results indicate that moderate hydrothermal–citric acid washing modification leads to the removal of aluminum from the zeolite framework, reducing the amount and strength of acid but increasing the mesopore quantity. This helps control the reaction pathways and diffusion of intermediate products, suppresses some side reactions, and improves the selectivity and yield of the desired product, propylene, while significantly enhancing catalytic stability. [ABSTRACT FROM AUTHOR]

Poly(butylene succinate) (PBS) exhibits many advantages, such as renewability, biodegradability, and impressive thermal and mechanical properties, but is limited by the low melt viscosity and strength resulted from the linear structure. To address this, vitrimeric network was introduced to synthesize PBS vitrimers (PBSVs) based on dynamic imine bonds through melt polymerization of hydroxyl-terminated PBS with vanillin derived imine containing compound and hexamethylene diisocyanate using trimethylolpropane as a crosslinking monomer. PBSVs with different crosslinking degrees were synthesized through changing the content of the crosslinking monomer. The effect of crosslinking degree on the thermal, theological, mechanical properties, and stress relaxation behavior of the PBSVs was studied in detail. The results demonstrated that the melt viscosity, melt strength, and heat resistance were enhanced substantially without obvious depression in crystallizability, thermal stability, and mechanical properties through increasing crosslinking degree. In addition, the PBSVs exhibit thermal reprocessability with mechanical properties recovered by more than 90% even after processing for three times. Furthermore, PBSV with improved melt properties shows significantly improved foamability compared to commercial PBS. This research contributes to the advancement of polymer technology by successfully developing PBS vitrimers with improved properties, showcasing their potential applications in sustainable and biodegradable materials. [ABSTRACT FROM AUTHOR]

Poly (butylene succinate) PBS is considered one of the most interesting biodegradable polymers because of the good compromise of mechanical strength, ductility, toughness, and impact resistance. To change the properties of PBS, modified poly (butylene succinate-co-butylene adipate-co-ethylene succinate-co-ethylene adipate) (PBEAS) was developed. Meanwhile, polylactide (PLA) is one of the commercially used eco-friendly polymers but is limited for commercial applications due to its brittleness and relatively slow hydrolysis. In this study, we explore potential synergistic effects of blending PLA with PBS and PLA with PBEAS, and their properties before and after hydrolytic degradations were investigated as a function of degradation time. [ABSTRACT FROM AUTHOR]

Two copolymer polyethylenes of raised temperature resistance (PE-RT) were used to analyze their basic properties and molecular structure, including their basic physical properties, molecular weight and distribution, molecular chain structure, and aggregation structure of the product; the crystallization kinetics and other properties differences are also discussed. The results showed that the basic physical properties of the two resins were similar, but there were still some differences in molecular structure. The molecular weight of PE-RT-1 was slightly lower in the range of 500,000–1,000,000 molecular weight, and slightly higher in the range of <500,000 molecular weight than PE-RT-2. The crystallization capacity of the crystallizable part of PE-RT-2 was slightly better than that of PE-RT-1. The comonomer (1-butene) content and polymer branching degree of PE-RT-2 were higher than those of PE-RT-1. The crystallinity of PE-RT-1 products was higher than that of PE-RT-2, and the lattice structure of PE-RT-1 was more complete and had good heat resistance. In addition, the butene content of PE-RT-2 with high molecular weight was higher than those of PE-RT-1, which was more conducive to the generation of tie molecules. [ABSTRACT FROM AUTHOR]

Poly(butylene succinate-co-furandicarboxylate) (PBSF) and poly(butylene adipate-co-furandicarboxylate) (PBAF) are novel furandicarboxylic acid-based biodegradable copolyesters with great potential to replace fossil-derived terephthalic acid-based copolyesters such as poly(butylene succinate-co-terephthalate) (PBST) and poly(butylene adipate-co-terephthalate) (PBAT). In this study, quantum chemistry techniques after molecular dynamics simulations are employed to investigate the degradation mechanism of PBSF and PBAF catalyzed by Candida antarctica lipase B (CALB). Computational analysis indicates that the catalytic reaction follows a four-step mechanism resembling the ping-pong bibi mechanism, with the initial two steps being acylation reactions and the subsequent two being hydrolysis reactions. Notably, the first step of the hydrolysis is identified as the rate-determining step. Moreover, by introducing single-point mutations to expand the substrate entrance tunnel, the catalytic distance of the first acylation step decreases. Additionally, energy barrier of the rate-determining step is decreased in the PBSF system by site-directed mutations on key residues increasing hydrophobicity of the enzyme's active site. This study unprecedently show the substrate binding pocket and hydrophobicity of the enzyme's active site have the potential to be engineered to enhance the degradation of copolyesters catalyzed by CALB. [ABSTRACT FROM AUTHOR]

Highlights This paper reports on preparing two types of graphene oxide‐zinc oxide (GO‐ZnO) nano‐hybrids and their effect on the performance of polybutylene succinate (PBS) matrix. This view synthesized GO, ZnO, and GO‐ZnO nano‐hybrids at 1:1 and 1:2 weight ratios. Subsequently, various spectroscopy and microscopy analyses (FTIR, UV, Raman, AFM, and TEM) were employed to characterize the structure of synthesized nanomaterials. The obtained results revealed that the hybridization was successfully occurred and microstructure of two types of prepared nano‐hybrids are basically different depending on the preparation procedure. Following this, PBS nanocomposites with 0.5, 1, and 1.5 wt% of GO‐ZnO nano‐hybrids (NPs) were produced via the solvent‐blending method. The mechanical, microstructural, rheological, biodegradability and UV‐shielding properties of the fabricated films were then investigated. Mechanical properties showed that addition of 0.5 wt% ZnO‐GO nanohybrids improved elongation at break from 21.6% to 28.7% and increased tensile strength by 20%. However, rheological assessments showed a one‐order‐of‐magnitude decrease in viscosity with the addition of only 0.5 wt%. In degradation analysis, 100 percent of mass loss was observed during 5 weeks for PBS with 1.5 wt% of GO‐ZnO. PBS/GO‐ZnO nanocomposites indicated tailored mechanical properties, biodegradability, suggesting a promising potential in packaging applications. GO‐ZnO nanohybrids were successfully synthesized. Incorporating GO‐ZnO into PBS improved its hydrolytic degradation The thermal decomposition of PBS was accelerated by the addition of GO‐ZnO. Adding GO‐ZnO nanohybrids to PBS resulted in a drop in viscosity. Nanohybrids with higher ZnO content exhibited greater hydrolytic and thermal degradation. [ABSTRACT FROM AUTHOR]

Highlights Poly(butylene adipate‐co‐terephthalate) with or without thermoplastic starch is often used as a biodegradable matrix in composites reinforced with 5 and 10 wt% of either microfibrillated cellulose or cellulose nanocrystals. If dispersion of the fillers is well studied, their orientation in melt blended composites requires further understanding. In this study, the effect of a controlled shear rate on the orientation of the filler was investigated to understand how shear rate affects orientation and how orientation affects mechanical properties of the composites. To this end, composites prepared by melt mixing and then compressed were taken as a reference state of low orientation. On the contrary, to orient the fillers, extrusion through a slit die with a determined shear rate was carried out. Results of tensile tests, microscopic observations, atomic force microscopy and dynamic mechanical analysis in the melt showed that orientation of fillers in the flow axis was possible for shear rates higher than 13 s−1. The orientated samples presented enhanced mechanical properties in the elastic domain as opposed to unoriented samples. In general, orientation of fillers leads to uniaxial stiffness at lower filler content with much better ductility. However, this was observed only on samples for which the percolation of the filler was not obtained in the unoriented state, otherwise, orientation proved to be detrimental to the elastic mechanical properties because of the rupture in the formed network. Orientation can be controlled during processing. Sufficient shear rate is required. Orientation improves mechanical properties. Orientation might have a negative effect on rigidity in case of existing network. [ABSTRACT FROM AUTHOR]

As an important biodegradable and partially biobased copolyester, poly(butylene succinate-co-terephthalate) (PBST) possesses comparable thermal and mechanical properties and superior gas barrier performance when compared with poly(butylene adipate-co-terephthalate) (PBAT), but it was found to display poorer melt processability during pelletizing and injection molding. To make clear its melt crystallization behavior under rapid cooling, PBST48 and PBST44 were synthesized, and their melt crystallization was investigated comparatively with PBAT48. PBST48 showed a PBAT48-comparable melt crystallization performance at a cooling rate of 10 °C/min or at isothermal conditions, but it showed a melt crystallization ability at a cooling rate of 40 °C/min which was clearly poorer. PBST44, which has the same mass composition as PBAT48, completely lost its melt crystallization ability under the rapid cooling. The weaker chain mobility of PBST, resulting from its shorter succinate moiety, is responsible for its inferior melt crystallization ability and processability. In comparison with PBAT48, PBST48 displayed higher tensile modulus, and both PBST48 and PBST44 showed higher light transmittance. The findings in this study deepen the understanding of PBST's properties and will be of guiding significance for improving PBST's processability and application development. [ABSTRACT FROM AUTHOR]

This study focused on the development and optimization of thermoplastic starch (TPS) and poly(butylene adipate‐co‐terephthalate) (PBAT) biobased active packaging films by incorporation with grape seed oil, alpha‐tocopherol, and rice husk. In the compound and film production step during extrusion for biobased active packaging film two variables, the antioxidant substance concentration (Grape seed oil, 0.5–4%; alpha‐tocopherol, 0.5–4%; rice husk, 1–5%), TPS concentration (60–90%) were optimized through response surface methodology (RSM) for highest tensile strength (MPa) and antioxidant activity (%) as responses. Among the resulting films, samples containing grape seed oil in particular exhibited an optimal balance, showcasing robust mechanical properties alongside potent antioxidant characteristics. Comprehensive analyses encompassing thickness, density, color, opacity, FTIR spectroscopy, total phenolic content, and energy consumption were conducted to assess the films' viability for potential deployment within the food industry. Based on the findings, it was determined that these biobased active packaging films made of TPS/PBAT held promise in safeguarding food products. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the advancement of society, the issue of oil pollution is escalating, therefore we propose a straightforward and efficient approach for fabricating fully biodegradable poly (lactic acid) (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) foams with exceptional selective oil-absorption capabilities through the integration of melt blending and supercritical CO2 (scCO2) foaming techniques. The PLA90 foams, activated at 11 MPa and temperatures ranging from 105 ℃ to 110 ℃, exhibit an expansion ratio of 44 and a highly interconnected open-cell structure with an open-cell content exceeding 80%, effectively mitigating cell shrinkage occurrences. The 105 ℃-triggered PLA90 foam displays pronounced lipophilicity/hydrophobicity, accelerated oil-absorption kinetics, and elevated oil-absorption capacity. Specifically, the equilibrium absorption capacities for cyclohexane and silicone are 12.8 g/g and 20.1 g/g, respectively. Moreover, the maximum absorption capacity decline rate for silicone oil stands at a mere 13.4% over 10 absorption–desorption cycles. The findings presented in this study establish a theoretical framework and offer empirical evidence to support the development of fully biodegradable, high-performance, and reusable oil-absorption materials. [ABSTRACT FROM AUTHOR]

Poly(butylene adipate‐co‐terephthalate) (PBAT) is an important biodegradable copolymer, but its crystallization rate is slow. Herein, the effect of self‐nucleation on the crystallization behavior of PBAT with initially different crystalline modifications (melt‐crystallized specimens and as‐received pellets) was investigated. The melt‐crystallized and as‐received PBAT specimens are confirmed as the α‐ and β‐form, respectively. It is found that the self‐nucleation domains of β‐form PBAT are almost the same as those of α‐form one. After self‐nucleation, the maximum shift of the crystallization peak toward higher temperature is around 60 °C upon the followed cooling process, suggesting that self‐nucleation remarkably promotes PBAT crystallization. The self‐nucleation temperature span of self‐nucleation domain is about 10 °C, which provides substantial benefits to industrial processing. Moreover, for both the initial α‐ and β‐form PBAT, the final crystal is α‐form after self‐nucleation treatment. This work demonstrates that self‐nucleation is highly effective in enhancing PBAT crystallization. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) grafted glycidyl neodecanoate (GND) with a single epoxy group (PLA‐GND) is prepared in this paper by solid phase grafting, and the effects of different reaction conditions on the grafting percentage of PLA‐GND are investigated. Furthermore, PLA‐GND is used as a nonreactive compatibilizer to prepare PLA‐GND/PLA/poly(butylene adipate‐co‐terephthalate) (PBAT) composite by melt blending. The results show that PLA‐GND has the highest grafting percentage of 2.15% when the feed weight ratio of GND to PLA is 0.2, the feed weight ratio of triphenylphosphine to PLA is 0.02, the additive amount of xylene is 1 mL, the reaction temperature is 120°C, and the reaction time is 115 min. The GND segments of PLA‐GND and PBAT segments could form a physical entanglement microdomain because of the similar aliphatic chain of GND and PBAT, which would improve the compatibility of PLA and PBAT. PLA‐GND/PLA/PBAT composite has the highest tensile strength, elongation at break, impact strength, crystallinity, heat deformation temperature, and melt flow rate at a PLA‐GND content of 5%, which are 38.54 MPa, 118.65%, 15.83 kJ/m2, 5.71%, 65.3°C, and 36.3 g/10 min, 14.53%, 390.90%, 68.94%, 224.43%, 16.19%, and 224.40% higher than those of PLA/PBAT composite, respectively. Highlights: PLA grafted GND with a single epoxy group is prepared by solid phase grafting.PLA‐GND as a non‐reactive compatibilizer compatibilizes PLA/PBAT composite.The similar chain of GND and PBAT is helpful to form the physical entanglement.The physical entanglement is essential to improve compatibility of PLA and PBAT.PLA/PBAT composite has excellent overall performance at a PLA‐GND content of 5 wt%. [ABSTRACT FROM AUTHOR]

Poly(butylene 2,5‐thiophenedicarboxylate) (PBTh) is a novel biobased semicrystalline polyester with superior thermal, mechanical, and gas barrier properties; however, the crystallization kinetics and melting behavior of PBTh have not been studied in detail so far. The crystallization kinetics of PBTh was first studied in this research. The Ozawa equation failed to describe the nonisothermal melt crystallization kinetics of PBTh due to the secondary crystallization. The crystallization activation energy value was calculated by the Friedman method, which was negative and exhibited the conversion dependence. The isothermal melt crystallization kinetics of PBTh was well described by the Avrami equation in a wide range of crystallization temperature from 84 to 120 °C. PBTh showed the fastest crystallization rate at 104 °C; moreover, the Avrami exponent value slightly varied between 2.2 and 2.7, suggesting the same crystallization mechanism within the investigated temperature range. PBTh displayed one or two melting endotherms depending on crystallization temperature, which was well explained by the melting, recrystallization, and remelting mechanism. In addition, the equilibrium melting point of PBTh was estimated to be 163.1 °C with the Hoffmann−Weeks equation. [ABSTRACT FROM AUTHOR]

Two biodegradable polyesters, poly(butylene succinate) (PBS) and poly(butylene succinate‐co‐adipate) (PBSA), were artificially aged in a UV irradiation test chamber, and their photodegradation behaviors investigated. The attenuated total reflection (ATR) infrared (IR) spectra of the initial and UV‐aged samples revealed conformational changes in the tetramethylene sequences of the photoaged PBS and PBSA. The one‐dimensional wide‐angle X‐ray scattering (WAXS) profiles showed that the (110) d‐spacing of the α‐form crystal progressively decreased during UV aging, suggesting that the crystalline polymer chains became arranged more closely along the fiber axis. Accordingly, we conclude that PBS and PBSA transform from their TGTGT to nearly TTTTT conformations upon photoaging. The observed WAXS, small‐angle X‐ray scattering, and IR spectral data suggest that photodegradation preferentially occurs in the amorphous phase of each polymer. The less crystallizable butylene adipate co‐unit enhances the degradability of PBSA, with prolonged photooxidation leading to partial degradation of the crystalline region of the copolymer. This finding is consistent with and may be linked to the higher biodegradability of PBSA compared to PBS. [ABSTRACT FROM AUTHOR]

Ethylene dimerization is an efficient industrial chemical process to produce 1‐butene, with demanding selectivity and activity requirements on new catalytic systems. Herein, a series of monodentate phosphinoamine‐nickel complexes immobilized on UiO‐66 are described for ethylene dimerization. These catalysts display extensive molecular tunability of the ligand similar to organometallic catalysis, while maintaining the high stability attributed to the metal–organic framework (MOF) scaffold. The highly flexible postsynthetic modification method enables this study to prepare MOFs functionalized with five different substituted phosphines and 3 N‐containing ligands and identify the optimal catalyst UiO‐66‐L5‐NiCl2 with isopropyl substituted nickel mono‐phosphinoamine complex. This catalyst shows a remarkable activity and selectivity with a TOF of 29 000 (molethyl/molNi/h) and 99% selectivity for 1‐butene under ethylene pressure of 15 bar. The catalyst is also applicable for continuous production in the packed column micro‐reactor with a TON of 72 000 (molethyl/molNi). The mechanistic insight for the ethylene oligomerization has been examined by density functional theory (DFT) calculations. The calculated energy profiles for homogeneous complexes and truncated MOF models reveal varying rate‐determining step as β‐hydrogen elimination and migratory insertion, respectively. The activation barrier of UiO‐66‐L5‐NiCl2 is lower than other systems, possibly due to the restriction effect caused by clusters and ligands. A comprehensive analysis of the structural parameters of catalysts shows that the cone angle as steric descriptor and butene desorption energy as thermodynamic descriptor can be applied to estimate the reactivity turnover frequency (TOF) with the optimum for UiO‐66‐L5‐NiCl2. This work represents the systematic optimization of ligand effect through combination of experimental and theoretical data and presents a proof‐of‐concept for ethylene dimerization catalyst through simple heterogenization of organometallic catalyst on MOF. [ABSTRACT FROM AUTHOR]

A low-temperature melt blending method was adopted to prepare ternary blends of poly(L-lactide) (PLLA), poly(butylene carbonate) (PBC), and poly(D-lactide) (PDLA), aiming to obtain fully biodegradable blends with well-balanced properties. The in situ formation of stereocomplex polylactide (SC-PLA) crystals was confirmed by torque changes, differential scanning calorimetry results, and wide-angle X-ray diffraction measurements. At a PDLA concentration of 5 mass%, SC-PLA crystals formed a percolating network structure, and the rheological behavior of the blend melts transformed from liquid-like to solid-like. The viscosity ratio between PLLA and PBC melts increased due to the presence of SC-PLA crystals, resulting in an enlargement of the PBC domain size. SC-PLA crystals exhibited an excellent nucleation effect, significantly accelerating the crystallization rate of PLLA. Compared to neat PLLA with elongation at break of 5.2%, PLLA/PBC/PDLA ternary blends containing 2 mass% PDLA with elongation at break of 247.2% presented excellent toughness. This work provided a facile method to prepare PLLA-based material with outstanding crystallization ability and tailored rheological behavior as well as mechanical properties, which had the potential to replace conventional plastic products. [ABSTRACT FROM AUTHOR]

In this study, a series of biodegradable poly(butylene alkylene carboxylate‐co‐terephthalate) copolymers with varying methylene numbers in the alkylene units (0, 2, 4, and 8) are synthesized. These copolymers, namely, poly(butylene oxalate‐co‐terephthalate) (PBOT), poly(butylene succinate‐co‐terephthalate) (PBST), poly(butylene adipate‐co‐terephthalate) (PBAT), and poly(butylene sebacate‐co‐terephthalate) (PBSeT), are prepared with nearly identical structural and molar compositions. The objective of this study is to comprehensively examine the impact of alkylene unit length on the barrier properties of the materials, delving into aspects such as crystallinity, free volume, molecular chain mobility, as well as adsorption and diffusion of gases within the materials. The findings indicate a decrease in crystallinity from 17.2% for PBOT to 10.2% for PBSeT as the alkylene chain length increases, while maintaining the same chemical composition. Concurrently, the fractional free volume increases from 0.9% to 2.6%, and the melt flow activation energy decreases from 106.6 to 52.1 kJ mol−1. Importantly, theoretical calculations are performed, demonstrating that the predominant site for gas adsorption and diffusion is within the material's free volume. These combined observations indicate a gradual decrease in barrier properties as the number of methylene groups increases. [ABSTRACT FROM AUTHOR]

Since monomers in backbone of poly(butylene succinate-co-adipate) (PBSA) are not entirely derived from bio-based sources, limiting its application in the face of increasingly stringent environmental policies. In this study, a novel full bio-based biodegradable random copolyester poly(butylene succinate-co-sebacicate-co-salicylicate) was successfully synthesized. Detailed investigations were conducted on the structural, mechanical, and degradation characteristics resulting from the introduction of salicylicate and sebacicate units. Introduction of salicylicate units effectively enhanced the mechanical performance. In comparison to PBSA, the tensile modulus of copolymer increased by 20.2% with 10% salicylic acid. Introduction of sebacicate units significantly altered the crystalline structure of copolymer and promote the degradation efficiency. Considering both mechanical strength and degradation efficiency, the copolyester with 2% salicylic acid and 20% sebacic acid was found to meet practical application requirements. Relative to PBSA, this copolymer demonstrated a 13.7% increase in tensile modulus and a remarkable 143.1% improvement in degradation efficiency. Importantly, this study focused on the effect of the bio-based rigid monomer salicylic acid and the soft monomer sebacic acid on the degradability of biodegradable polymers. The insights gained provide valuable guidance for tailoring the synthesis of degradable plastics to meet diverse degradation cycle requirements. [ABSTRACT FROM AUTHOR]

Poly (butylene terephthalate) (PBT)/poly (ethylene glycol‐co‐cyclohexane‐1, 4‐dimethanolterephthalate) (PETG) blends were prepared by melt blending using a twin screw extruder. The non‐isothermal crystallization behaviors of PBT/PETG blends were investigated using differential scanning calorimetry (DSC). The results showed that the crystallization peaks of the PBT/PETG blends moved gradually toward lower temperature and the crystallinity decreased with the increase of PETG content. The PBT/PETG blends all show double melting peaks, which the low‐melting peak temperature Tm1 becomes lower as the cooling rate increases, but the high‐melting peak temperature Tm2 is not related to the cooling rate. The Jeziorny's method showed that the faster the cooling rate is, the shorter the crystallization time is required for the PBT/PETG blends. The Mo's method showed that the crystallization rate of the blends initially decreased and then increased with the addition of more PETG. The activation energy of non‐isothermal crystallization calculated by the Kissinger method is similar to that of the Takhor method. Highlights: The efficient blending of PBT and PETG was realized by twin screw extruder, which opened up a new way for the preparation of polymer materials.The crystallization behavior of PBT/PETG blends was successfully regulated, and the effect of PETG content on the crystallization peak temperature and crystallinity was revealed.The crystallization characteristics and kinetic behavior of the blends were comprehensively evaluated by DSC, Jeziorny method, Mo Zhishen method, and Kissinger method. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) is a kind of polyester from biomass. To increase the ductility of PLA, melt blending was used to prepare the polylactic acid/poly(butylene diglycolate) blends in this study. The effect of poly(butylene diglycolate) (PBD) on the thermal, crystallization, tensile, and dynamic mechanical properties of PLA was investigated. The blend containing 30 wt% PBD has a substantially improved elongation at break (79%) due to the lower glass transition temperature of PBD compared to PLA. The results indicated that PLA and PBD exhibited partial compatibility, which was confirmed by dynamic mechanical analysis (DMA) and scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FTIR) analysis showed there is the interaction between PLA and PBD. In summary, the incorporation of PBD resulted in improved mechanical properties, indicating potential for applications requiring enhanced ductility. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA), which is widely used in degradable packaging and medicine, has attracted much attention in recent years. However, PLA's ductility and processability still need to be improved. Previous literature indicated that poly(butylene diglycolate-co-butylene terephthalate) (PBDT) had good ductility, and degradability due to the introduction of diglycolic acid's ether group. Based on the above advantages of PBDT, the PLA/PBDT blends were prepared to improve the ductility of PLA. The blends' thermal, crystallinity, mechanical, and rheological properties and compatibility were characterized. The blends all showed greater elongation at break compared to PLA. The WAXD results showed that the tensile specimens of PBDT were semi-crystalline, and the tensile specimens of PLA and the blends were almost amorphous. The incorporation of PBDT caused the fracture behaviour of the blends to change from brittle to ductile behaviour. It is concluded that PBDT can effectively improve the ductility of PLA and the blend with 20 wt.% PBDT has high elongation at break (135%). [ABSTRACT FROM AUTHOR]

Efforts to develop and implement an increasing number of biodegradable polymers continue to grow worldwide; nevertheless, substantial obstacles must undoubtedly be surmounted in order to produce biodegradable polymers that exhibit exceptional properties and high performance. With the objective of enhancing the compatibility between the two intrinsically immiscible polymers, polybutylene adipate-co-terephthalate (PBAT) and poly(butylene adipate) (PLA), we employed epoxidized polyhedral oligomeric silsesquioxanes (epoxy-POSS) nanoparticles. A solution-casting method was employed to fabricate nanocomposites comprising a nanoparticle and two biocompatible polymers. This process proved to be highly effective. The distinctive morphology, high strength, toughness, and thermal stability of these nanocomposites were demonstrated by a variety of experiments at 1 wt% nanoparticle. The opposite effect was observed when nanoparticles were added exceeding 1 wt%; consequently, the degree of compatibility between the polymer phases diminished. The impact strength and elongation-at-break of the composite samples were significantly altered at 1% nanoparticle application, going from 57.04 MPa and 520% to about 400% and 62.4 MPa, respectively, as compared to pristine PLA. Microscopic observations showed that the dispersion of nanoparticles in all three phases was dispersed, continuous, and the interface was uniform, and the presence of nanoparticles prevented the melt crystallization of PLA. [ABSTRACT FROM AUTHOR]

Polybutylene terephthalate (PBT) nanocomposites were melt-blended with two types of Turkish halloysite nanotubes (HN). Naturally occurring HN samples were used to produce PBT-based composites at the HN compositions of 1%, 3%, 5%, and 10%. Findings of neat and silane-coated HN-containing composite samples were compared to investigate the interfacial adhesion between polymer matrix and reinforcement material. According to test results, a 1% amount of HN was found to be the most suitable option in the case of mechanical and thermal properties of composites. Additionally, silane-modified grade displayed highly indicative improvements compared to pristine HN clay due to better interfacial adhesion of halloysite nanotubes to the PBT matrix was accomplished. Property enhancements achieved for composite samples containing low contents of HN were confirmed by morphological examinations. As a result, the PBT/ 1% HN-S composite sample was bookmarked as the most suitable option to fabricate HN-reinforced PBT-based nanocomposites in terms of mechanical, thermo-mechanical, morphological, thermal, and physical performances based on the findings in this study. Silane-modified halloysite grades exhibited better results, and they were found to be more suitable in the case of applications of PBT. [ABSTRACT FROM AUTHOR]

The application of polymer composites is one of the most effective methods for preventing lubrication failure in deep‐sea engineering. In this study, fluorinated graphite (FGr) microsheets were incorporated into polytetrafluoroethylene (PTFE) microparticle‐filled poly(butylene terephthalate) (PBT) composites. The tribological performance in the simulated deep‐sea environment at elevated seawater pressure equivalent to 3000 m ocean depth was investigated. The results showed that FGr enhances the flexural and compressive strengths, thermal stability, and seawater resistance of the PTFE/PBT composite. The wear rate was decreased to 96% at the critical FGr content of 4% by improving the transfer onto the metallic counterfaces, preventing direct contact and shear between friction couples. Moreover, the seawater pressure impedes composite transfer, leading to a 29% increase in the wear rate. [ABSTRACT FROM AUTHOR]

The non‐biodegradability of Ethylene‐Propylene Side‐by‐Side (ES) fibers has led to significant environmental pollution from waste sanitary products, thereby posing a severe challenge to the environment. Replacing traditional non‐biodegradable materials with biodegradable polymeric materials is the most effective method to achieve a green environment. In this study, core‐sheath fibers composed of biodegradable poly (butylene adipate‐co‐terephthalate) (PBAT) as the sheath layer and polylactic acid (PLA) as the core layer were fabricated. The effects of different viscosity ratios and the composite ratios of sheath and core on the structure and performance of the resultant core‐sheath fibers were investigated in detail. The results showed that when the PBAT/PLA composite ratio is 50:50 and the viscosity ratio range from 0.8 to 1.43, the PBAT/PLA core‐sheath composite fibers exhibit good spinnability and a complete core‐sheath structure, with their tensile properties comparable to those of PP/PE core‐sheath composite fibers. Further research found that when the viscosity ratio was 1.00 and the PLA component content in the PBAT/PLA composite fibers increased from 40% to 60%, the fibers still maintained good spinnability and a complete core‐sheath structure. In addition, when the PBAT/PLA composite ratio was 60:40, after 120 days of biodegradation, its strength retention rate was only 35.2%. [ABSTRACT FROM AUTHOR]

Fiber‐based products constitute a significant portion of plastic waste and cause environmental damage. In particular, discarded sanitary masks and fishing gear disintegrate into microfiber plastics, posing a significant threat to human health and ecosystems. In this study, we developed robust biodegradable nanocomposite fibers of poly(butylene adipate‐co‐terephthalate) (PBAT)/cellulose nanocrystals (CNCs) (1 and 2 wt%) through dry‐jet wet spinning, by using dimethyl sulfoxide (DMSO) as a common solvent. The control PBAT fibers exhibit remarkable mechanical performance with tensile strength and toughness of 160.0 MPa and 43.0 MJ m−3, respectively. CNC addition has a toughening effect with slightly reduced strength but enhanced toughness (148.8 MPa and 69.0 MJ m−3, respectively, for 2 wt% CNC); their mechanical performances are superior to those of previously reported PBAT‐based materials. The remarkable performance of the fibers is attributed to a highly oriented structure with a total draw ratio of 15 after post‐hot drawing. The control and nanocomposite fibers exhibit spot‐like patterns in 2D wide‐angle x‐ray diffraction patterns with Herman's orientation factor of 0.54–0.58. The theoretical Hansen solubility parameter confirmed the poor chemical affinity between the PBAT and CNC. Nonetheless, the rheological characterization revealed that well‐dispersed CNCs with DMSO produced a physical network in the PBAT matrix, resulting in the toughening effect. Such robust nanocomposite fibers consisting of fully biodegradable components are promising alternatives to nondegradable nylon and polyester fibers. Highlights: Robust biodegradable nanocomposite fibers of PBAT and CNC are prepared.Nanocomposite fibers are dry‐jet wet spun using DMSO as a common solvent.PBAT fibers exhibit strength and toughness of 160.0 MPa and 43.0 MJ m−3.2 wt% CNC toughens the PBAT fibers with an enhanced toughness of 69.0 MJ m−3.Rheological results confirm the toughening effect of well‐dispersed CNC in PBAT. [ABSTRACT FROM AUTHOR]

Biodegradable green composites of poly(butylene succinate) (PBS) and poly(L-lactide) (PLA) fibers were initially melt-blended aiming to obtain balanced comprehensive properties. According to the morphological observations, the PLA fibers were uniformly embedded in the PBS matrix. Rheology measurements suggested that the incorporation of PLA fibers improved the viscoelasticity of PBS melt. The percolation network of PLA fibers was formed at content of 20 wt%. The presence of PLA fibers inhibited the crystallization and reduced the isothermal crystallization rate of PBS in the composites. Moreover, the reinforcing effect of PLA fibers on the PBS matrix was found to be very significant. The storage modulus and tensile modulus of the composite with 30 wt% PLA fibers were 74% and 94% higher than those of neat PBS, respectively. PBS/PLA fiber composites prepared by simple melt blending method displayed the combination of enhanced melt strength and modulus, while maintaining the biodegradability of PBS matrix, which is of great potential for the wider practical application of environmentally friendly polymers. [ABSTRACT FROM AUTHOR]

A method has been developed to quantify PET and PBT microplastics (MPs) based on depolymerization and detection of depolymerization products by gas chromatography-tandem mass spectrometry (GC–MS/MS) without a complex separation process from environmental samples. Under the optimal depolymerization conditions, PET and PBT were efficiently converted to ethylene glycol (78%) and 1,4-butanediol (87%), respectively. Subsequently, the linear curves were constructed between signal intensities of depolymerization products and polymer masses by GC–MS/MS, and the correlation coefficients of PET and PBT were 0.996 and 0.997, respectively. The spiking and recovery experiments of PET and PBT in the environmental samples showed that the recovery was stable in the range 89–100%, and the limit of detection was 4.95 μg and 1.39 μg of PET and PBT, respectively. The method has been proven to be capable of simultaneous identification and quantification of PBT and PET MPs in real environmental water samples without complex separation process, which provided a scheme for the determination of microplastics. [ABSTRACT FROM AUTHOR]

Poly(butylene adipate-co-terephthalate) (PBAT) foam is regarded as one of the ideal alternatives to petroleum-based polymer foams in view of its advantages of lightweight, high elasticity, biodegradability and biocompatibility, while the problem of shrinkage after foaming has seriously limited its application in industry. In this paper, the no-shrinkage chain-extend PBAT-glycerin monostearate (GMS) foams with ultra-high volume expansion ratio (VER) were prepared by scCO2-assisted molten foaming method. The chain extension reaction between PBAT and chain extender (CE) were investigated by torque curves, gel fraction and FTIR measurements. Comparing with torqued PBAT, the storage modulus of CE-PBAT2 specimen increased 3 orders of magnitude and their crystallization temperature rose from 72.5 to 87.2 ℃. Furthermore, the addition of GMS was beneficial to enhance the dimensional stability of CE-PBAT foams. When 2 phr CE and 2.5 phr GMS were incorporated into PBAT, CEPBAT-GMS2.5 foam attained ultra-high VER of 25.38 times, resilience ratio of 87% with no-shrinkage, which revealed admirable compression and resilience properties. In conclusion, this study provided a feasible new method for improving the VER and dimensional stability of PBAT foams. [ABSTRACT FROM AUTHOR]

The production and application of biodegradable polycarbonate have been significantly facilitated by the scale production of dimethyl carbonate which is the downstream of carbon dioxide. Hence, the progress in current research of novel biodegradable aliphatic poly(butylene carbonate) (PBC) modification has been reviewed. The mechanism of monomer structure (i. e. linear aliphatic monomer, cyclic aliphatic monomer, and aromatic monomer) and blending compatibility effect on thermal properties, crystallization, and tensile properties of PBC were analyzed. In addition, the application and development were also prospected according to the structure-properties relationship of PBC-based copolycarbonate and PBC-based blends. [ABSTRACT FROM AUTHOR]

A type of blending films ba,sed on poly (butylene adipate-arterephthalate) (PBAT) and poly(lactic-fo-butane-diol itaconate) (PLBI) were prepared at different ma,s,s ratio,s through melt extrusion using a twin-screw extruder. The effect of PLBI content on the thermal performance, mechanical propertie,s, and ga,s permeability of the blending film,s wa,s inve,stigated. The modified atmossphere packaging (MAP),sy,stem wa,s de,signed on the ba,si,s of the ga,s permeability of material and the re,spiratory characteri,stic,s of sstrawberry. Thi,s MAP,sy,stem wa,s used for a,strawberry-pre,serving experiment. The results indicated that the blended films achieved favorable mechanical properties at a PLBI content of 15 wt%. Through adjusting the blending ratio, the CO2/O2 penetration ratio of the blending film,s wa,s reduced from 10. 57 to about 3-7. Simultaneously, the water retention capacity of the blending film,s wa,s enhanced. Thi,s make,s the blending filmss more ssuitable for air-adjusted fruit and vegetable packaging. Thi,s packaging,sy,stem can be used to extend the shelf life of strawberries up to 21 days under low-temperature storage conditions. [ABSTRACT FROM AUTHOR]

A multifunctional epoxy polymer wass used ass a chain extender for poly (butylene ssuccinate-co-terephthalate) (PBST), and the effects of chain extension condition on the propertiess of PBST/Talc (talcum powder) blendss were in-vesstigated during the melt-phasse reactive extrusion processss. The chain extender dossage, reaction temperature, and sscrew rotational sspeed were sstudied ass main factorss. The primary influence factors and their interactions were identified through an analyssiss of variance. The ressultss indicated that the influence of chain extender dossage iss mosst ssignificant, followed with a reaction temperature, whereass the influence of sscrew sspeed iss lessss. The melting and crysstallization temperaturess of PBST decreassed with an increasse in the chain extender dossage, and meanwhile its molecular weight, melt visscossity, and thermal sstability increassed. The modified PBST compounds* pressented an increasse in the breaking sitresis; but a decreasse in the breaking sstrain with an increasse in the chain extender dossage. Ressponsse ssurface analyssiss indicated that the optimal chain extenssion condition wass a chain extender dossage of 0. 66 %, a reaction temperature of 200 °C, and a sscrew sspeed of,300 r/min. [ABSTRACT FROM AUTHOR]

Herein, the nanofibrillated poly(butylene succinate)/polytetrafluoroethylene (PBS/PTFE) composites were prepared. The relaxation time was prolonged by PTFE fibrils, resulting in an enhancement in storage modulus and melt viscosity. Differential scanning calorimetry was used to study the non-isothermal crystallization kinetics at different cooling rates. These results showed that PTFE fibrils could promote crystallization nucleation and excessive fibrils could inhibit crystallization growth. Lightweight PBS/PTFE composite foams were fabricated using core-back foam injection molding. Loading the PTFE fibrils increased the cell density of PBS foam from 2.7×106 to 1.4×108 cells/cm3 and improved the cell morphology of PBS foam. By controlling the foaming parameter, the tensile properties of PBS-based composite foam with 1 wt.% PTFE were improved overall, and the Izod impact strength was increased by 9–69% compared with the PBS foam. [ABSTRACT FROM AUTHOR]

Biodegradable poly(butylene succinate-co-2-methyl succinate) (PBSMS)/cellulose nanocrystals (CNC) composites were successfully prepared at low CNC loadings with the aims of improving crystallization and mechanical properties and extending the practical application of PBSMS. CNC is finely dispersed in the PBSMS matrix without obvious aggregations. The low content of CNC obviously promoted the crystallization behavior of PBSMS under different conditions. The spherulitic morphology study revealed that CNC, as an effective heterogeneous nucleating agent, provided more nucleation sites during the melt crystallization process. In addition, the nucleation effect of CNC was quantitatively evaluated by the following two parameters, i.e., nucleation activity and nucleation efficiency. The crystal structure and crystallization mechanism of PBSMS remained unchanged in the composites. In addition, as a reinforcing nanofiller, CNC significantly increased Young's modulus and the yield strength of PBSMS. The crystallization behavior and mechanical properties of PBSMS were significantly improved by the low content of CNC, which should be interesting and essential from the perspective of biodegradable polymer composites. [ABSTRACT FROM AUTHOR]

Thermoformed fossil‐based disposable packaging is widely used in everyday life but it represents a serious environmental problem, as it is often incorrectly dispersed or destined to landfills. Bio‐based and biodegradable materials can constitute and effective solution to this issue. Two different blends of poly(butylene succinate‐co‐butylene adipate) (PBSA) and Poly (3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) (PHBH) were studied as constituents for disposable packaging production. The blends were produced via twin screw extrusion. Sheets were cast extruded and then thermoformed into trays. A rheological, thermal and mechanical characterization was performed on compounds and manufacts. Both blends presented a good processability and interesting properties for packaging application, which can be tailored by varying the percentage of constituent polymers. [ABSTRACT FROM AUTHOR]

In this paper, the foam-like multi-stage porous 3wt%Al-KIT-6-4T(WI) catalyst was prepared and employed for efficient catalyzing biomass-derived GVL to butene. It is found that the prepared 3wt%Al-KIT-6-4T(WI) catalyst possess abundant mesoporous and presented the foam-like microstructure. Due to this, the 3wt%Al-KIT-6-4T(WI) catalyst has large specific surface area (517.09 m2·g−1) and adequate amount of surface acid sites (both Brønsted and Lewis acid site). The special microstructure further improves the mass transfer efficiency of reactants and products. Under the optimized reaction conditions, the butene yield over the 3wt%Al-KIT-6-4T(WI) catalyst can up to 93.78% at 300 °C, after reacting 240 min. Moreover, the 3wt%Al-KIT-6-4T(WI) catalyst still showed excellent regeneration stability, and above 72% butene yield can be maintained after 7th cycle tests. [ABSTRACT FROM AUTHOR]

Bioplastic films with excellent barrier properties were successfully prepared from poly(butylene adipate‐co‐terephthalate) (PBAT), thermoplastic starch (TPS), and poly((R)‐3‐hydroxybutyrate‐co‐(R)‐3‐hydroxyhexanoate) (PHBHHx). The rheological, mechanical, barrier, dynamic mechanical properties, and microstructure of the PBAT/TPS/PHBHHx films were studied. The transition of the continuous phase in the blend significantly affects the properties of the films. The increase in PHBHHx content results in its transition from a dispersed phase to a continuous phase. This phase transition, along with the consequent increase in the crystallinity of PHBHHx, greatly enhances the barrier properties of the film. The percentage crystalline degree of PHBHHx increased from 10.9% to 25.1% with increasing PHBHHx content from 0% to 50%. The film containing 50% PHBHHx showed a significant decrease in both water vapor permeability (WVP) and oxygen permeability (OP) by 75.1% and 69.6%, respectively. It found that the film containing 50% PHBHHx exhibited a decrease of elongation at break from 505% to less than 10% but an unusual increase of tensile strength after a 72‐hour aging test, which is different from PBAT and PBAT/TPS films. However, this indicates that the extensibility of PHBHHx is more susceptible to the effects of aging test, leading to the rearrangement of polymer chains from disordered to ordered morphology. [ABSTRACT FROM AUTHOR]

Copyright of Kobe College Studies / Kobe Jogakuin Daigaku Kenkyujo Yakuin is the property of Kobe College Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Simultaneously biaxial stretching was applied to poly(butylene succinate) (PBS), poly(butylene succinate-co-adipate) (PBSA), and their blends to investigate the effect of biaxial orientation (BO) on gas permeability and mechanical strength, compared to their thin films. The BO process with a high draw ratio of 4 × 4 and a rapid rate of 300 mm/s effectively induced the formation of both perfect α-PBS crystals and small PBS crystal-like aggregates. The distinctive crystallization behaviors of PBS and PBSA, coupled with various film stretching processes, played crucial roles in crystal formation and orientation, resulting in distinct properties of the oriented films. The lattice plane (021) of α-PBS crystal predominantly formed with isotropic orientation through the BO process, while the (110) planes displayed isotropic formation along orthotropic orientation of the crystal c-axis. Conversely, uniaxial cast film extrusion favored preferential alignment of both (020) and (110) diffraction planes along the meridian direction. The perfect α-PBS crystals from PBS homopolymer played a critical role in enhancing gas barrier performance, while the specific orientation of crystalline phase and PBS fringed-micelle crystals proved insufficient in reducing gas diffusivity within the films. Furthermore, the limited crystallization capability of PBSA copolymer disrupted the densely packed structures of α-PBS crystalline phase, resulting in increased d-spacing with higher PBSA content in the PBS/PBSA blend. Remarkably, the simultaneous BO process enabled balanced tensile properties along both the machine and transverse directions of the PBS, PBSA, and PBS/PBSA films, with a substantial enhancement (3 to 4-fold increase) in puncture toughness for BO films compared to thin films. [ABSTRACT FROM AUTHOR]