Novel Biodegradable and Double Crystalline Multiblock Copolymers Comprising of Poly(butylene succinate) and Poly(ε-caprolactone): Synthesis, Characterization, and Properties

Crystallization Behavior and Mechanical Property of Biodegradable Poly(butylene succinate-co-2-methyl succinate)/Cellulose Nanocrystals Composites

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.

Polybutylene Succinate, A potential bio-degradable polymer: Synthesis, copolymerization And Bio-degradation

Poly(butylene succinate) is one of the emerging bio-degradable polymer, which has huge potential to be employed in a wide range of applications. Further, it is also recognized as one of...

Dependence of Crystallization Behavior of Interacting Telechelic Poly(butylene succinate) Oligomer on Molecular Weight

A large spherulite structure deteriorates the mechanical properties of crystalline polymers, and therefore various methods have been explored to increase primary nucleation density. Recently, chain-end modification has been proposed as an effective approach for regulating polymer crystal nucleation. However, the relevant nucleation mechanism still requires investigation. Therefore, in this work, 2-ureido-4[1H]-pyrimidinone (UPy) units, which can form stacks via quadruple hydrogen bonds with each other, are introduced as end groups for the preparation of interacting telechelic poly(butylene succinate) (PBS-UPy) oligomers with different molecular weights (Mns). The crystallization, especially the nucleation behavior of PBS-UPy, is studied in detail by comparing with the corresponding pre-polymer, the hydroxyl-terminal PBS (PBS-OH). The thermal properties of PBS-UPy exhibit similar Mn-dependent tendency to those of PBS-OH, but with weaker total crystallization rate. The spherulite growth rate is significantly reduced, whereas the primary nucleation density is highly promoted, after introducing UPy groups. Further investigation reveals that the mechanism of UPy stacks’ influence on nucleation ability changes from inhibition to promotion with respect to Mn. Even under an inhibition of nucleation ability, the final nucleation density is obviously increased because of a significant decline of the growth rate. In addition, the change in the impact of UPy stacks on nucleation ability is speculated to originate from the memory expression feasibility of ordered conformation in the melt during crystallization.

Structure and Properties of Biodegradable Poly (Xylitol Sebacate-Co-Butylene Sebacate) Copolyester

In this work, a bio-based copolyester with good mechanical properties was synthesized and characterized in terms of structure, main properties and biodegradability Determining the chemical structure of such materials is important to understand their behavior and properties. Performing an extraction of insoluble cross-linked polymer using different solvents allowed us to analyze how the polymer behaves when subjected to different chemical environments, and to obtain soluble samples suitable for more in-depth analysis. Chemical structure of poly (xylitol sebacate-co-butylene sebacate) was determined by a 1H NMR and FTIR analysis of both prepolymer gel sample and samples obtained by extraction of cross-linked polymer using different solvents. Block structure of the copolymer was confirmed by both NMR and DSC. Gel fraction, swelling value, water contact angle, and mechanical properties were also analyzed. Biodegradability of this material was confirmed by performing enzymatic and hydrolytic degradation. Synthesizing sugar-alcohol based copolyester using three monomers leads to obtaining a material with interesting chemical structure and desirable mechanical properties comparable to conventional elastomers.

Synthesis, Properties of Biodegradable Poly(Butylene Succinate-co-Butylene 2-Methylsuccinate) and Application for Sustainable Release

A novel biobased and biodegradable polyester, i.e., poly(butylene succinate-co-butylene 2-methylsuccinate) (P(BS-BMS)) was synthesized by succinic acid (SA), 2-methylsuccinic acid (MSA), and 1,4-butanediol (BDO) via a typically two-step esterification and polycondensation procedure. The chemical structure and macromolecular weight of obtained copolymers were characterized by 1H NMR, 13C NMR, and GPC. The melting temperature and degree of crystallinity were also studied by DSC, and it was found that the values were gradually decreased with increasing of MSA content, while the thermal stability remained almost unchanged which was tested by TGA. In addition, the biodegradation rate of the P(BS-BMS) copolymers could be controlled by adjusting the ratio of SA and MSA, and such biodegradability could make P(BS-BMS) copolymers avoid microplastic pollution which may be brought to the environment for applications in agricultural field. When we applied P(BS-BMS) copolymers as pesticide carriers which were prepared by premix membrane emulsification (PME) method for controlling Avermectin delivery, an improvement of dispersion and utilization of active ingredient was obviously witnessed. It showed a burst release process first followed by a sustained release of Avermectin for a long period, which had a great potential to be an effective and environmental friendly pesticide-release vehicle.

Double Crystalline Multiblock Copolymers with Controlling Microstructure for High Shape Memory Fixity and Recovery

The shape memory performance of double crystalline poly(butylene succinate)-co-poly(ε-caprolactone) (PBS-co-PCL) multiblock copolymers with controlling microstructure was studied, and the corresponding microstructure origin was further quantitatively analyzed by wide and small-angle X-ray scattering (WAXS and SAXS) experiments. It was found that the multiblock copolymer with higher PCL content, proper deformation strain, and inhibited crystallization of PBS (lower crystallinity and smaller crystal size, which could be realized by quenching from the melt) would exhibit better shape memory fixity and recovery performance. WAXS and SAXS results revealed that the shape fixity ratio (R_f) was closely related with the relative crystallinity of the PCL component, while the shape recovery ratio (R_r) strongly relied on the deformation and recovery behavior of the PBS and PCL components that changed along with compositions and deformation strains. For the copolymer with higher PCL content (BS₃₀CL₇₀), at the lower deformation strain (0% ∼ 90%), both the PBS and PCL components after recovery had no orientation (labeled as stage I), resulting in almost complete recovery; with the deformation strain increasing (90% ∼ 200%), it was the irreversible deformation of the PCL component that largely took responsibility for the decreased R_r (stage II). On the contrary, when the PCL content decreased to 50 wt % (BS₅₀CL₅₀), stage I (0% ∼ 50%) and stage II (50% ∼ 100%) appeared in much lower strains; with the deformation strain increasing (100% ∼ 200%), the irreversible deformation of both PBS and PCL components was mainly responsible for the further reduction of R_r (stage III). It could exhibit excellent shape memory performance for biodegradable double crystalline multiblock copolymers by controlling the composition, deformation strain, and crystallization, which might have wide application prospects in biomedical areas.

Structural and thermal properties of poly(1,4-cyclohexane dimethylene terephthalate) containing isosorbide

Poly(1,4-cyclohexanedimethylene isosorbide terephthalate) (PICT) copolymers were synthesized by melt condensation with various contents of the corn derived monomer isosorbide (ISB).