摘要
用4,4′-二苯基甲烷二异氰酸酯(MDI)对端羟基聚碳酸亚丙酯(PPC)进行扩链改性,考察了实验条件及MDI用量对反应的影响。用凝胶渗透色谱法对产物进行测试发现,随着MDI用量的增加,产物的数均分子量增加,相对分子质量分布变窄。通过对产物进行红外光谱测试,从峰的变化可看出MDI和端羟基发生了反应,生成了预期产物。通过对产物的热重分析发现,w(MDI)分别为0.5%,1.0%,2.0%时,最大分解温度由扩链前的257.64℃分别提高至274.40,278.22,279.49℃,热稳定性得到改善;且热降解方式由解拉链式降解逐渐变为主链无规断链降解。
Hydroxyl-terminated poly（propylene carbonate）（PPC） was modified via chain extension with 4,4＇ -diphenylmethane diisocyanate（MDI）. The influence of experimental conditions and the MDI dosage on the chain extension reaction was studied. The analysis by gel permeation chromatography（GPC） reveals that the numberaverage molecular mass increases and the relative molecular mass distribution narrows with augmentation of the MDI dosage. The reaction of MDI with hydroxyl group and the formation of the target product are verified by the variation in location of the peaks on Fourier transform infrared spectra（FTIR） of the resultant. The thermogravimetric （TG） data indicate that when MDI mass content is 0.5%, 1.0% or 2.0%, the maximum decomposition temperature rises to 274.40, 278.22, 279.49 ℃, respectively, from 257.64 ℃ before chain extension. The PPC＇s thermal stability is improved and its pyrolysis mechanism gradually changes from unzipping into main chain random scission.
出处
《合成树脂及塑料》
CAS
北大核心
2011年第2期16-19,共4页
China Synthetic Resin and Plastics
关键词
端羟基聚碳酸亚丙酯
4
4'-二苯基甲烷二异氰酸酯
扩链
热稳定性
hydroxyl-terminated poly（propylene carbonate）
4,4＇-diphenylmethane diisocyanate
chain extension
thermal stability
