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In this study, a series of poly(butylene succinate)-based copolymers containing various quantities of dimethyl 2,6-naphthalene dicarboxylate (NDC) were synthesized via melt polymerization. The thermal stabilities of the copolymers were maintained, while a slight increment in the stability was observed as the NDC content increased. The results of differential scanning calorimetry and wide-angle X-ray diffraction demonstrated a reduction in the crystallizability of the copolymers with increasing NDC concentration. Unexpectedly, the tensile tests showed significant enhancement of the elongation rate from 122.5 to 2645.0% as the NDC content increased from 0 to 32 mol%. Samples with 28, 30, and 32 mol% NDC showed remarkable abilities with recovery rates above 90% after three test cycles. Moreover, apparent cut mark repairing behaviors were observed under 70 °C heating in samples containing 25, 28, and 30 mol% NDC. These results indicate the potential of the copolymers for self-healing and highly stretchable shape memory wound dressing material applications. [ABSTRACT FROM AUTHOR]

To improve the glass transition temperature and ultraviolet shielding properties of poly(butylene 2,5-thiophenedicarboxylate) (PBTF), a series of poly(butylene 2,5-thiophenedicarboxylate-co-butylene 4,4′-biphenyldicarboxylate) (PBTFBs) were synthesized from 2,5-thiophenedicarboxylic acid (TDCA), 1,4-butanediol (BDO), and dimethyl 4,4′-biphenyldicarboxylate (BDD). The composition and molecular weights of PBTFBs were investigated by 1H NMR,.13C NMR and GPC. The results showed that the glass transition temperature of PBTFBs gradually increased, and the thermogravimetric analysis results also showed that the thermal stability gradually increased with increasing the BDD content. Compared with PBTF, the polyester with 40% butylene 4,4′-biphenyldicarboxylate unit (PBTFB40) showed a higher Young's modulus (1166.8 MPa) and tensile strength (25.8 MPa). In addition, the ultraviolet (UV) shielding ability of PBTF was greatly enhanced, and the UV transmittance at 350 nm decreased from 19.66% (PBTF) to 6.22% (PBTFB30). The average transmittance at wavelengths of 320–400 nm decreased from 26.25 to 15.20%. The gas permeability coefficient of CO2 decreased from 0.3120 barrer to 0.0321 barrer. Because the biphenyl structure was successfully introduced into PBTF, the rigidity of the chain segment was improved, and excellent thermal stability, mechanical properties and UV shielding properties were obtained. PBTFB30 has potential application in outdoor products. [ABSTRACT FROM AUTHOR]

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Poly(1,4-butylene succinate) (PBS) is a promising sustainable and biodegradable synthetic polyester. In this study, we synthesized PBS-based copolyesters by incorporating 5–20 mol% of –O2CC6H4CO2– and –OCH2CH2O– units through the polycondensation of succinic acid (SA) with 1,4-butanediol (BD) and bis(2-hydroxyethyl) terephthalate (BHET). Two different catalysts, H3PO4 and the conventional catalyst (nBuO)4Ti, were used comparatively in the synthesis process. The copolyesters produced using the former were treated with M(2-ethylhexanoate)2 (M = Mg, Zn, Mn) to connect the chains through ionic interactions between M2+ ions and either –CH2OP(O)(OH)O− or (–CH2O)2P(O)O− groups. By incorporating BHET units (i.e., –O2CC6H4CO2– and –OCH2CH2O–), the resulting copolyesters exhibited improved ductile properties with enhanced elongation at break, albeit with reduced tensile strength. The copolyesters prepared with H3PO4/M(2-ethylhexanoate)2 displayed a less random distribution of –O2CC6H4CO2– and –OCH2CH2O– units, leading to a faster crystallization rate, higher Tm value, and higher yield strength compared to those prepared with (nBuO)4Ti using the same amount of BHET. Furthermore, they displayed substantial shear-thinning behavior in their rheological properties due to the presence of long-chain branches of (–CH2O)3P=O units. Unfortunately, the copolyesters prepared with H3PO4/M(2-ethylhexanoate)2, and hence containing M2+, –CH2OP(O)(OH)O−, (–CH2O)2P(O)O− groups, did not exhibit enhanced biodegradability under ambient soil conditions. [ABSTRACT FROM AUTHOR]

• High molecular weight biodegradable PBIxSe copolyesters were successfully synthesized by one-pot polycondensation with 1,4-butanediol, isosorbide and sebacic acid. • The crystallinities of PBIxSe exhibited a decline as the content of IS units increased. • The introduction of IS unit accelerated the enzymatic hydrolysis rate of PBIxSe. • PBIxSe represented the biodegradability of compost, soil, seawater. The growing environmental concerns associated with the use of plastics highlight the need to mitigate carbon emissions and environmental pollution via biodegradable plastics development. Herein, biotechnologically accessible and renewable building blocks, namely 1,4-butanediol and sebacic acid, were copolymerized with carbohydrate-derived isosorbide to afford random poly(butylene-co-isosorbide sebacate) with variable isosorbide content. The thermal stabilities of these copolyesters and their biodegradabilities under (non)enzymatic hydrolysis, compost, soil, and marine conditions were examined as functions of isosorbide content. With the increasing isosorbide content, the glass transition temperature increased, whereas the crystallinity and melting temperature decreased. Isosorbide incorporation enhanced hydrolyzability under alkaline and enzymatic conditions, while demonstrating minimal impact under neutral and acidic conditions. The in-compost degradation rate increased with the increasing isosorbide content because of the concomitant decrease in melting temperature and crystallinity. In soil and marine environments, the copolyesters were degraded faster than poly(butylene sebacate). At 30 mol% isosorbide, the degradation extent reached 97.2 and 68.3 % after eight-week degradation in soil and 32-week degradation in a marine environment, respectively. This study is the first to report the biodegradability and degradation mechanisms of poly(butylene-co-isosorbide sebacate) and provides valuable insights into customizing the synthesis of biodegradable plastics to meet the degradation cycle requirements under various environmental conditions. [ABSTRACT FROM AUTHOR]