A process for the preparation of high molecular weight polyethylene glycol oxalate

Abstract

This invention discloses a method for preparing high molecular weight poly(oxalic acid) glycol ester, belonging to the technical field of biodegradable polyester materials. The method includes: mixing a natural mineral carrier with ethylene glycol at a mass ratio of 1:0.8 to 1:1.2 to form dispersed particles with a particle size of 100-500 μm and a porosity of 30%-70%; adding oxalic acid and 0.2%-2% (by mass) of catalyst at a molar ratio of oxalic acid to ethylene glycol of 1:1 to 1:1.2; esterifying at 60-100 °C under normal pressure for 2-8 h; collecting the intermediate solution after filtration to separate the carrier; and obtaining the number-average molecular weight polymer by dehydration at 120-160 °C and vacuum polycondensation at 170-200 °C and below 200 Pa for 4-12 h. M n The product yields PEO with a strength greater than 80 kDa. The preferred support is natural minerals such as kaolin, and the preferred catalyst is tetraisobutyl titanate. This invention utilizes a carrier-based slow-release mechanism to suppress side reactions. The process is simple, low-cost, and the carrier is recyclable. The product exhibits excellent performance and is suitable for industrial production.

Images