Enzymatic Synthesis and Characterization of Hydrophilic Sugar Based Polyesters and Their Modification with Stearic Acid

• Published in: Polymers
• Main Authors: Muhammad Humayun Bilal, Marko Prehm, Andrew Efraim Njau, Muhammad Haris Samiullah, Annette Meister, Jörg Kressler
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2016
• Subjects: enzymatic synthesis; biodegradable polyesters; sugars; graft copolymers; stearic acid; crystallization; nanoparticles; Organic chemistry; QD241-441; antartic*
• Online Access: https://doi.org/10.3390/polym8030080; https://doaj.org/article/84726e740b1541c3b2b8feb7f065e3a2

Biodegradable and hydrophilic functional polyesters were synthesized enzymatically using xylitol or d-sorbitol together with divinyl adipate and lipase B from Candida antartica (CAL-B). The resulting polyesters had pendant OH-groups from their sugar units which were esterified to different degrees with stearic acid chloride. The structure and the degrees of polymerization of the resulting graft copolymers based on poly(xylitol adipate) and poly(d-sorbitol adipate) were characterized by 1H NMR spectroscopy and SEC. DSC, WAXS and SAXS measurements indicated that a phase separation between polymer backbone and stearoyl side chains occurred in the graft copolymers, and, additionally, the side chains were able to crystallize which resulted in the formation of a lamellar morphology. Additionally, nanoparticles of the graft copolymers in an aqueous environment were studied by DLS and negative stain TEM.