PREPARATION OF FUNCTIONAL POLYMER BEADS BASED ON POLY (2-OXAZOLINE)

苯乙烯与链端带有季铵基团的嵌段型两亲性聚（2-恶唑啉）大分子单体进行乳液共聚合，以制备亚微米范围内的单分散聚合物颗粒。粒径随大分子单体浓度的降低而增大。以聚2-乙基-2-恶唑啉为聚合物稳定剂，苯乙烯在乙醇水溶液中进行分散聚合，制备了微米级单分散聚苯乙烯粒子。随着溶剂中水含量的增加，聚合速率和聚合物颗粒的分子量增加，并且颗粒尺寸减小。稳定剂和引发剂的浓度也影响粒子的大小和分布。以聚（2-乙基-2-恶唑啉）为稳定剂，在极性介质中进行N-乙烯基甲酰胺的分散聚合。在甲醇中的聚合得到微米级单分散的高度亲水性聚合物颗粒。粒径随着稳定剂浓度的降低而增大。在二乙烯基化合物存在下的聚合得到交联聚合物颗粒。用带有可聚合苯乙烯基的亲水性聚（2-恶唑啉）大分子单体代替聚（2-乙基-2-恶唑啉），得到了亚微米级的单分散聚合物粒子。大分子单体充当稳定剂以及共聚单体。大分子单体的取代基影响粒径。

Emulsion copolymerization of stirene with a block-type amphiphilic poly (2-oxazoline) macromonomer having a quaternary ammonium group at the chain end was performed to produce monodisperse polymer particles in the sub-micron range. The particle diameter increased with decreasing the macromonomer concentration. Poly (2-oxazoline) chains and the ammonium group were localized on the particle surface.Dispersion polymerization of stirene in an aqueous alcohol solution using poly (2-ethyl-2-oxazoline) as a polymeric stabilizer was carried out to prepare micron-size monodisperse polystirene particles. As the water content of the solvent increased, the polymerization rate and the molecular weight of the polymer particles increased and the particle size decreased. The concentration of stabilizer and initiator also affected the particle size and size distribution.Dispersion polymerization of N-vinylformamide in polar media has been performed using poly (2-ethyl-2-oxazoline) as stabilizer. The polymerization in methanol gave micron-size monodisperse particles of highly hydrophilic polymers. Particle size increased as the stabilizer concentration decreased. The polymerization in the presence of a divinyl compound afforded crosslinking polymer particles. In using a hydrophilic poly (2-oxazoline) macromonomer bearing polymerizable styryl group instead of poly (2-ethyl-2-oxazoline) , monodisperse polymer particles in the sub-micron range were obtained. The macromonomer acted as a stabilizer as well as a comonomer. The substituent of the macromonomer affected the particle size.