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用一种新的苯乙烯 乳化剂 引发剂体系 ,通过微乳液聚合得到了聚苯乙烯(PS)纳米粒子 (直径为 2 0～ 43nm) ,并用凝胶色谱、激光光散射、透射电子显微镜测量了PS的分子量、粒子的平均粒径和质量 ,由此计算每个PS粒子所包含的平均分子链数 (Np) .系统地考察了单体、乳化剂和引发剂浓度对分子量、粒径和Np 的影响 .以一种每个纳米粒子中平均含 4根分子链的寡链聚苯乙烯颗粒 ( 4CPS)为例 ,用调制型示差扫描量热计、Fourier红外光谱、荧光光谱、固体13 C 核磁共振分别研究了原始的 4CPS颗粒 ,以及经冷冻、玻璃化转变温度以上热处理及溶解浇铸成膜后样品的热行为、光谱和分子运动特征 .结果进一步表明 ,在原始的 4CPS中 ,链段间凝聚缠结较少 ,而经冷冻和热处理后 ,形成了更多的凝聚缠结 .
Polystyrene (PS) nanoparticles (20 ~ 43 nm in diameter) were obtained by microemulsion polymerization using a novel styrene emulsifier initiator system and were characterized by gel permeation chromatography, laser light scattering and transmission electron microscopy PS molecular weight, the average particle size and mass of the particles, thereby calculating the average number of molecular chains per PS particle (Np) .Systemically investigated monomer, emulsifier and initiator concentration of molecular weight, particle size and Np In this paper, an oligomeric polystyrene particles (4CPS) containing an average of four molecular chains per nanoparticle were used as an example, Resonance The thermal behavior, spectral and molecular motions of the original 4CPS particles, as well as the samples after heat treatment and solution casting at temperatures above freezing and glass transition temperature, were investigated respectively.The results further show that in the original 4CPS, Tangle less, and after freezing and heat treatment, the formation of more cohesive tangle.