论文部分内容阅读
以碱土金属氨钙为催化剂,经环氧乙烷的开环聚合得到聚氧化乙烯(PEO),考察了陈化温度和催化剂用量对聚合反应的影响。结果表明,陈化温度对聚合收率的影响较小,但影响聚合物分子量的波动程度;陈化温度为60℃的催化剂表现最为稳定,不仅聚合收率保持在99%以上,不同批次间聚合物的分子量波动程度(以变异系数表示)也降至最低,达7.3%。通过改变催化剂用量,可以在保持高聚合收率的情况下稳定地合成不同分子量级别(39万~86万)的PEO。SEM、XRD和DSC表征结果进一步表明,所得PEO粉末是一种具有层状结构的部分结晶性聚合物,且结晶度随分子量的增加而增大。
Polyethylene oxide (PEO) was obtained by ring-opening polymerization of ethylene oxide with alkaline earth calcium as catalyst. The effects of aging temperature and amount of catalyst on the polymerization reaction were investigated. The results showed that the aging temperature had little effect on the polymerization yield, but the fluctuation degree of the molecular weight was affected. The catalyst with the aging temperature of 60 ℃ exhibited the most stable performance. The polymerization yield was maintained above 99% The degree of molecular weight fluctuation (expressed as coefficient of variation) of the polymer was also minimized to 7.3%. By varying the amount of catalyst, PEO of various molecular weight classes (390,000 to 860,000) can be stably synthesized while maintaining a high polymerization yield. SEM, XRD and DSC characterization results further show that the resulting PEO powder is a partially crystalline polymer with a layered structure, and the crystallinity increases with increasing molecular weight.