【摘要】 以原子转移自由基偶联法合成了多臂星形聚合物S-PS和星形杂臂共聚物PS-PMMA.采用傅立叶红外光谱(FT-IR)和核磁共振(1H NMR)分析方法确定了产物的结构.采用GPC法测定了产物的分子量和分子量分布.GPC分析结果表明偶联剂的偶联效率高,所得聚合物分子量增大,分子量分布窄.以DSC法研究了S-PS和PS-PMMA的热力学行为,并与相应线性均聚物的热力学行为进行了比较.发现星形PS相对线性PS均聚物,其玻璃化转变温度有所降低,且随PS臂数增加,其玻璃化转变温度降低程度明显.星形杂臂共聚物PS-PMMA只存在一个玻璃化转变温度.更多还原

【Abstract】 Multi-arm star polystyrene and miktoarm star styrene-methyl methacrylate copolymers were synthesized by atom transfer radical coupling reaction.Their structures were confirmed by Fourier Transform Infrared（FT-IR） spectra,proton nuclear resonance(¹H NMR) and gel permeation chromatograph（GPC）.GPC studies revealed the higher coupling efficiency and the narrow polydispersities（<1.4） of the resulting polymers.Their thermotropic phase transition behaviors were characterized by differential scanning calorimetry（DSC）.Compared with the related linear polymers,star polystyrene had a lower glass transition temperature(T_g),which decreased notably as the number of arms increased.Miktoarm star styrene-methyl methacrylate copolymers showed only one T_g from DSC observation.更多还原