大粒径单分散聚合物交联微球的制备

采用分散聚合法制备出粒径8.21μm,分散系数约为0.04,交联度约为12.6%的单分散聚合微球,考察了交联剂加入方式用量,加入时间及抗坏血酸用量等因素对合成聚合物PS微球粒径和分布的影响.实验结果表明,当单体St质量分数为28.8%～33.5%,引发剂用量m(AIBN)∶m(St)=0.03～0.06,稳定剂用量m(PVP)∶m(St)=0.5～0.8,采用交联剂DVB后滴入法,交联剂用量m(DVB)∶m(St)=0.02～0.08,在反应进行到6h后开始滴加DVB,2h滴加完,可合成出单分散性好、分散系数低、大粒径高交联的PS微球.

Preparation of Large Particle Size Monodispersed Polystyrene Microspheres with High Crosslinked Degree

Monodispersed polystyrene microspheres with 8.21 μm were prepared successfully by dispersion polymerization process.The dispersion coefficient of most particle sizes(PS) could be controlled within 0.04 and crosslinked degree was about 12.6%.The major factors that affect the particle size and size distribution were investigated such as the dosage and mode of adding DVB crosslinked agent,concentrations of monomer,initiator and stabilizer,and ascorbic acid.It is concluded that,the prepared polystyrene microspheres have good mono-dispersion,low dispersion coefficient,large particle size and highly cross linked degree under the following appropriate synthesized process.The mass fraction of styrene monomer is 28.8%~33.5%.The mass ratio of initiator: azodiisobutyronitrile and St is 0.03~0.06.The mass ratio of stabilizer: polyvinyl-pyrrolidone and St is 0.5~0.8.DVB crosslinked agent is add in the solution drop by drop,the mass ratio of cross linked agent: divinylbenzene and St is 0.02~0.08.DVB should be released completely within 2 h after the reaction began to 6 h.