致孔剂用量对苯乙烯悬浮聚合微球粒径和密度的影响

Density and particle size of polymer microsphere in suspension polymerization of styrene at different amounts of porogen

以苯乙烯(St)为单体,正庚烷为致孔剂,偶氮二异丁腈(AIBN)为引发剂,聚乙烯醇(PVA)为分散剂,用悬浮聚合法制备聚合物微球,在转速和分散剂一定的条件下,研究致孔剂用量对聚苯乙烯微球粒径和密度的影响。结果表明,微球的粒径和密度均受致孔剂含量的影响。致孔剂含量影响初始液滴大小、致孔剂均匀分布、液滴中致孔剂和聚苯乙烯比例、相分离难易和微球的溶胀度等方面,这些因素共同影响微球粒径和密度。在实验条件范围内,V(致孔剂)∶V(St)=0.40时制备的微球粒径最大,平均粒径>1.6mm;V(致孔剂)∶V(St)=0.80时微球密度最低,为0.899 8g/cm3,漂浮率最高,为96.29%。

Formulation of latex with styrene （St）, N-heptane, azobisisobutyronitrile （AIBN） and polyvi- nyl alcohol（PVA）was investigated in the suspension polymerization,This paper studied the effects of the dosage of porogen on particle size distribution and density under certain stiring speed and content of PVA. The results showed that the particle size distribution and density of the polymer microspheres are subject to dosage of porogen. The size of the initial droplet, the distribution of porogen, the propor- tion of porogen and polystyrene in initial droplet, the complexity of phase separation and swelling of the microspheres are all related to the dosage of porogen,which all together influence the density and particle size of polymer microsphere. In the present experimental conditions,when the dosage of poro- gen is 40%, the particle size of polymer microspheres is the largest, when the dosage of porogen is 80% ,the density of microspheres is the lowest about 0. 899 8 g/cm3 ,the floating rate of microspheres is the highest about 96.29M.