Synthesis and characterization of biodegradable aliphatic copolyesters with poly(tetramethylene oxide) soft segments

Abstract

A series of aliphatic poly(ether-ester)s based on flexible poly(tetramethylene oxide) (PTMO) and hard poly (butylene succinate) (PBS) segments were synthesized by the catalyzed two-step transesterification reaction of dimethyl succinate, 1,4-butanediol, and a,x-hydroxy-terminated PTMO (M n 5 1000 g/mol) in the bulk. The content of soft PTMO segments in the polymer chains was varied from 10 to 50 mass %. The effect of the introduction of the soft segments on the structure, thermal, and physical properties, as well as on the biodegradation properties was investigated. The composition and structure of the aliphatic segmented copolyesters were determined by 1 H NMR spectroscopy. The molecular weights of the polyesters were verified by viscometry of dilute solutions and polymer melts. The thermal properties were investigated using DSC. The degree of crystallinity was determined by means of DSC and WAXS. Biodegradation of the synthesized copolyesters, estimated in enzymatic degradation tests on polymer films in phosphate buffer solution with Candida rugosa lipase at 378C, was compared with hydrolytic degradation in the buffer solution. Viscosity measurements confirmed that there was no change in molecular weight of the copolyesters leading to the conclusion that the degradation mechanism of poly(ester-ether)s based on PTMO segments occurs through the surface erosion.

Synthesis of high‐impact biodegradable multiblock copolymers comprising of poly(butylene succinate) and poly(1,2‐propylene succinate) with hexamethylene diisocyanate as chain extender

“…Although T m does not depress so sharply,7 tensile strength of block poly(ether‐ester)s generally deteriorates instead as the implantation of flexible macromolecular chain of polyethers 8, 9. Another significant disadvantage of block poly (ether‐ester)s is their long‐term instability under environmental conditions since the oxidative reaction of the ether bonds can be initiated by thermo‐, photo‐, or γ ‐radiation 10–12…”

Enzymatic Synthesis and Crosslinking of Novel High Molecular Weight Polyepoxyricinoleate

“…properties such as low melting temperatures [1]. In addition, the price of crude oil has increased in recent years, and the conservation of fossil resources is very important for establishing a sustainable society and reducing carbon dioxide emissions [2,3].…”

Challenges for Natural Monomers and Polymers: Novel Design Strategies and Engineering to Develop Advanced Polymers

“…Nguyen has reviewed this critically and properties such as thermal stability, mechanical properties, biodegradability, antibacterial activity, cell compatibility, etc., can be controlled through changing the nature and composition of the co-polymer [258]. Thus, various copolymers were combined with polyethers such as poly(ethylene glycol), polysaccharides such as cellulose and chitosan, polyesters suchas poly(lactic acid) and poly(ε-caprolactone), and vinyl polymers such as poly(methyl methacrylate and poly(2-hydroxyehtyl methacrylate) [259][260][261].…”