In situ functionalization of poly(butylene adipate-co-terephthalate) polyester with a multi-functional macromolecular additive

Poly(butylene adipate-co-terephthalate) (PBAT) has been functionalized with Pluronic F127 as a secondary diol monomer by melt polycondensation. The variation of Pluronic content to max 12.2 wt% in the copolymer is investigated on microstructure analysis, molecular weight distribution, thermal properties, crystallinity, and thermo-responsive behavior. The microstructure in the Pluronic F127-functionalized PBAT (PPBAT) copolymer indicates that the amount of Pluronic unit which is attached to the PPBAT copolymers found to be increased from 5.9 to 9.1 to 12.2% (wt) with the feeding amount of 1.0 to 2.0 to 3.0 mmol, respectively. The weight average molecular weight has also found to increase from 23,555 to 43,841 g/mol in the PPBAT copolymers. The lowering of glass transition temperature has been also observed in the thermal analysis that indicates the improvement of the plasticization effect in the PPBAT copolymers with the increase of Pluronic from 0 to 12.2% (wt). Moreover, the crystallization behavior also indicates the disappearance of crystallization temperature and the appearance of cold crystallization temperature before melting with the increase of Pluronic content. The X-ray diffraction analysis further signifies the decrease in degree of crystallinity with an increase of Pluronic in PPBAT copolymers. The PPBAT copolymers display thermo-responsive behavior under physiological conditions due to the attachment of Pluronic comonomer onto the structural backbone.