Effective ab initio emulsion polymerization under RAFT control
Effective ab initio emulsion polymerization under RAFT control
复制标题
DOI：
10.1021/ma025626j
复制
发表时间：
2002-12-03
期刊：
影响因子：
5.5
通讯作者：
Such, CH
中科院分区：
文献类型：
--
作者：
Ferguson, CJ;Hughes, RJ;Such, CH
结果、讨论和结论。在聚合完成时，所得胶乳显示无油层且无胶体不稳定性的可见证据。通过毛细管流体动力学分级分离（CHDF，Matec）测定粒度分布;数均直径随着转化率稳定增加，并且在完成时为60.3nm，多分散性为1.11（多分散性从150分钟时的第一次测量保持大致恒定）并且没有新颗粒形成的证据。图2示出了在不同转化率下胶乳的GPC迹线。28.5分钟后的峰对应于溶剂和其他低分子量物质; 27.5分钟后的峰是大分子RAFT试剂。图3示出了Mh n（相对于苯乙烯标准物）和Mh w/Mh n的值作为基于所添加的单体总量的转化率的函数。如所预期的，如果保持分子量控制，则Mh n随聚合物质量线性增加，尽管在最高转化率下在高分子量下出现小肩状物，
Results, Discussion, and Conclusions. At the completion of the polymerization, the resulting latex showed no oily layer and no visible evidence of colloidal instability. The particle size distribution was determined by capillary hydrodynamic fractionation (CHDF, Matec); the number-average diameter increased steadily with conversion, and at completion was 60.3 nm, with a polydispersity of 1.11 (the polydispersity remaining approximately constant from the first measurement at 150 min) and no evidence of new particle formation. Figure 2 shows GPC traces of the latex at different conversions. The peak after∼ 28.5 min corresponds to solvent and other low molecular weight species; that at∼ 27 min is the macro RAFT agent. Figure 3 shows the values of Mh n (relative to styrene standards) and Mh w/Mh n as functions of conversion based on the total amount of monomer added. Mh n increases linearly with mass of polymer, as expected if molecular weight control were maintained, although the appearance of a small shoulder at high molecular weight at the highest conversion