聚己内酯二元醇的合成研究

RESEARCH ON THE SYNTHESIS OF POLYCAPROLACTONE DIOL

以二乙二醇为起始剂,金属羧酸盐CAT-1为催化剂,通过ε-己内酯开环聚合反应制备了聚己内酯二元醇,采用核磁共振氢谱和碳谱进行了结构表征。实验结果表明:在达到反应温度(160℃)后的最初10 min,ε-己内酯转化率快速升高,从21.41%(0 min)升高到98.74%(10 min),反应15 min时即可达到99.43%,反应时间从2 h到5 h,ε-己内酯转化率变化幅度较小;随着反应时间的延长,产物酸值(KOH)从0.53 mg/g(1 h)降低到0.19 mg/g(5 h),氮气吹扫可有效降低产物中的酸性成分,产物M_n从1 790(1 h)升高1 990(5 h),而羟值(KOH)从62.69 mg/g(1 h)降低到56.38 mg/g(5 h),M_n与羟值的变化与酯交换反应有关。聚合反应动力学研究表明ln([M]_(0)/[M]_(t))与t成线性关系,该聚合反应为一级反应,属于活性聚合。

Using diethylene glycol as the starting agent and metal carboxylate CAT-1 as the catalyst,polycaprolactone diol was prepared by ring-opening polymerization ofε-caprolactone.Its structure was characterized by 1H NMR and 13 C NMR spectrum.The research results indicate that the conversion ofε-caprolactone rapidly increased from 21.41%(0 min)to 98.74%(10 min)in the first 10 minutes after reaching the reaction temperature(160℃),and reached 99.43%at the reaction time of 15 min.The conversion ofε-caprolactone varied little from reaction time of 2 h to 5 h.As the reaction time prolongs,the acid value of the product decreases from 0.53 mg/g(1 h)to 0.19 mg/g(5 h).Nitrogen blowing can effectively reduce the acidic components in the product.The relative molecular weight(M n)of the product increases while the hydroxyl value decreases,Mn increased from 1790(1 h)to 1990(5 h),and the hydroxyl value decreased from 62.69 mg/g(1 h)to 56.38 mg/g(5 h).The changes of M n and hydroxyl values are related to the transesterification reaction.Studies on the polymerization kinetics have found a linear relationship between ln([M]_(0)/[M]_(t)) and t,indicating that the polymerization reaction is a first-order reaction and belongs to active polymerization.