Accelerating polycondensation efficiency through introducing aromatic monofunctional alcohol

Abstract

Increasing the polycondensation rate of polyester is crucial for energy conservation, cost control, product quality, and improving production efficiency, as the process typically occurs under high temperature and vacuum conditions. To increase the rate, this study proposes a novel approach to accelerate the polycondensation of polybutylene succinate (PBS) by introducing benzyl alcohol as a comonomer. Experimental results show that the addition of benzyl alcohol significantly speeds up the polycondensation reaction. Without benzyl alcohol, the polymerization reaction required 170 min under a high vacuum to reach an intrinsic viscosity of 0.85 dL/g. With benzyl alcohol, the polymer's intrinsic viscosity can reach 1.31 dL/g in just 85 min. The accelerated polycondensation rate was revealed to stem from the high ester exchange activity of the benzyl ester groups and the significantly accelerated chain growth rate. Furthermore, density functional theory calculations further confirmed that the energy required for the removal of benzyl alcohol from the polymer chain was lower than that for 1,4-butanediol. Importantly, this method did not alter the physical properties of the polymer, suggesting the potential for industrial preparation. We believe that this approach holds significant practical value for polyester industrial production, particularly in terms of reducing production costs and improving production efficiency.