羟乙基纤维素接枝聚合及衍生基团取代值的测定

利用三甲基硅(TMS)基团改性保护技术,成功制备了羟乙基纤维素接枝聚己内酯(HEC-g-PCL)聚合物;利用红外光谱及核磁共振波谱对合成产物进行了结构验证;利用化学滴定法测定了原料HEC的醚化取代度,通过1H-NMR确定了中间产物的取代度及聚己内酯接枝侧链的重复单元数,并测定了终产物接枝聚己内酯侧链的接枝率和ε-己内酯接枝效率。研究结果有助于对反应历程的探讨。

Graft Polymerization of Hydroxyethyl Cellulose /Poly(Caprolactone) and Determination of the Substitution Value of Derivative Group

With the protection technique of the trimethylsilyl (TMS) groups, ε-caprolactone (CL) was successfully grafted on hydroxyethyl cellulose (HEC) to prepare hydroxyethyl cellulose-graft-poly caprolactone (HEC-g-PCL). The structures of the intermediate product and the end product were carefully characterized by FT-infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectroscopy (NMR). The results confirm that the copolymer newly synthesized is as expected. The molar degree of substitution (MS) of HEC was determined by chemical titration, and the trimethylsilyl MS of the intermediate product and the repeated number of PCL grafting side chain were determined by ~1H-NMR. Moreover, the grafting ratio of PCL side chain and grafting efficiency of CL were also ascertained. The investigation on the substitution values of derivative groups of raw material, intermediate product and end product will be beneficial to further research on the reaction mechanism of the graft copolymerization.