文献类型：期刊文献

英文题名：Molecular weight distribution of poly(methyl methacrylate) produced in a starved feed reactor

作者：Cao, G.-P.[1]; Zhu, Z.-N.[1]; Zhang, M.-H.[1]; Le, H.-H.[1]

机构：[1]E China Univ Sci & Technol, UNILAB Res Ctr Chem React Engn, Shanghai 200237, Peoples R China

年份：2001

卷号：21

期号：5

起止页码：401

外文期刊名：JOURNAL OF POLYMER ENGINEERING

收录：;EI(收录号：2001556799980);WOS:【SCI-EXPANDED(收录号:WOS:000172301000001)】；

语种：英文

外文关键词：molecular weight distribution; radical polymerization; a starved feed reactor; methylmethacrylate; termination

摘要：A starved feed reactor (SFR) is a semi-batch polymerization reactor where initiator and monomer are fed slowly into a fixed amount of solvent. The polymerization is carried out isothermally at elevated temperatures. The added initiator decomposes instantaneously and the added monomer polymerizes immediately. The molecular weight (MW) and the molecular weight distribution (MWD) of the polymer can be effectively controlled by the feed ratio of monomer to initiator. This paper presents a study on the MWD of methyl methacrylate (MMA) polymerization in a SFR. The MWD model parameters are regressed with experimental data. Although the solids fraction in the SFR is high (higher than 50%), viscosity is not high and the "get effect" is weak due to the low molecular weight of the products. It is found that the termination rate constant is a power function of the polymer concentration in the system; radicals terminate via disproportionation and combination. The fraction of disproportionation is about 0.9-0.96 at temperatures in the range of 100 degreesC-170 degreesC. The initiation efficiency f is about 0.82-0.55, and it decreases with increasing reaction temperature.