Influence of preparation process on acid value of DEG-polycaprolactone-diol
DEG-polycaprolactone diol was prepared using diethylene glycol(DEG)to initiate ring-opening polymerization of ε-caprolactone by bulk polymerization process.The microstructure of the product was analyzed,and the effects of three kinds of preparation processes and their process conditions on the acid value of DEG-polycaprolactone-diol were studied.The results showed that the polymer in the product was identified as DEG-polycaprolactone-diol by nuclear magnetic resonance hydrogen spectrum analysis,the conversion rate of ε-caprolactone was 99.81%,and the residual content of ε-caprolactone was 0.19%by mass fraction in the product;the acid value of the product was high under the conditions of"nitrogen pressure maintenance"(process A);the acid value of the product could be effectively reduced,but the reaction time would be extended under the con-ditions of"nitrogen pressure maintenance,followed by nitrogen purging"(process B);the acid value of the product(based on potassium hydroxide)was below 0.35 mg/g,and the reaction time was 6 h and below under the conditions of"dehydration before reaction,nitrogen purging during reaction,and devolatilization after reaction"(process C);the acid value of the product could be efficiently reduced by decreasing the water content of ε-caprolactone before reaction and adopting nitrogen purging during reac-tion;and process C was more suitable for the large-scale production of DEG-polycaprolactone-diol.
ε-caprolactonering-opening polymerizationpolycaprolactone diolacid value
万方数据
维普
