FeBr3/Me6TREN催化MMA反向原子转移自由基聚合研究

对FeBr3/Me6TREN催化的反向原子转移自由基聚合进行了研究.在不同的催化剂、引发剂的配比、聚合温度和配体用量等条件下,该催化体系催化的MMA聚合反应动力学为一级反应,聚合物分子量可控,分子量分布很窄,说明该体系催化的聚合反应为活性可控聚合.通过实验计算了反应的活化能,并利用UV光谱对催化剂进行了研究.

Synthesis and Characterization of PLGA-(ASP-DIOL)x-PLGAs Copolymer Containing Pendant Amino Groups with Different Densities

A series of poly(ASP-Diol)-xs were prepared by polycondensation reactions of N-CBz-L-aspartic acid anhydride with diols of different molecular weights including ethylene glycol, triethylene glycol, PEG200 and PEG600, respectively. They were used as the macromonomer initiators respectively to synthesize biodegradable copolymers PLGA-(ASP-Diol)-x-PLGAs containing pendant amino groups with different contents by ring-opening copolymerization of lactide/glycolide(molar ratio {75/25}). Their structures were confirmed by {}1H NMR, FTIR, EA, DSC and GPC. The results indicate that the main factor that affects the molecular weights of the prepolymers is not the molecular weights of diols, but the activity of the end hydroxyl groups. With increasing the chain length of the diols, the content of amino groups in the copolymers decreased, and the glass translation temperature(T-g) decreased obviously, therefore, it is considered that the content and distribution of amino groups in the copolymers can be effectively adjusted by changing the chain length of the diols.