Novel photocrosslinkable and biodegradable polyester from bio-renewable resource

Novel photocrosslinkable and biodegradable polyester with was synthesized by polycondensation of 3,4-dihydroxycinnamic acid (DHCA) and 10-hydroxycapric acid (HDA) which were derived form lignin and castor oil respectively. The molecular structure of poly(DHCA-co-HDA) copolymers was characterized by FTIR and 1H NMR measurement. The presence of HDA in the copolymers enhanced the flexibility of macromolecular chain, thus it lowed the glass transition temperature and accelerated the photoreactivity of polyester. Poly(DHCA-co-HDA) copolymers exhibited fairly good tensile properties. The elongation at break was enhanced with increasing the content of HDA. After UV photo-crosslinking, the tensile strength was further improved and elongation at break decreased. The hydrolysis experiments revealed that copolymers are facile biodegradable, and the hydrolysis rate of was accelerated after photo-crosslinking.