Synthesis and characterization of novel potentially biodegradable aromatic polyesters consisting of divanillic acids with free phenolic hydroxyl groups

Abstract

Potentially biodegradable bio-based polyesters (P6DVAs) were synthesized from 1,6-hexanediol and divanillic acid (DVA) with free hydroxyl groups. Four DVA-based monomers with different silyl protecting groups were synthesized. Each silyl protected monomer was polymerized with 1,6-hexanediol by bulk transesterification using tetraisopropyl orthotitanate as a catalyst at 140–180 °C (first step), and 200–220 °C under vacuum (second step). Triisopropylsilyl (TIPS) -protected DVA polymerization proceeded without the elimination of TIPS groups, and a TIPS-protected DVA polyester was obtained. After deprotection of the TIPS groups, a P6DVA (weight-average molecular weight; Mw = 3.9 × 104, polydispersity; 1.4) was obtained. The P6DVA was an amorphous polymer with a glass transition point of 108 °C. Environmental degradability was assessed by a biochemical oxygen demand (BOD) test using a mixture of fresh water and soil collected from a pond. The BOD degradability of the P6DVA was 8% over 40 days, indicating its potential as a degradable polymer.