摘要
采用^(13)C-NMR及二正丁胺滴定法研究了端羟基聚乙二醇(PEG)与异佛尔酮二异氰酸酯(IPDI)之间反应的动力学特征,发现在三苯基铋(TPB)的催化下,对[NCO]是零级反应,即反应与IPDI分子上两个-NCO基团的活性无关,当以二月桂酸二丁基锡(DBTDL)为催化剂时,对[NCO]为二级反应,而且与异佛尔酮脂环的碳原子相连的-NCO表现较强的反应能力.采用DBTDL与TPB混合催化时,反应表现为二者的加和作用,混合催化剂的应用有利于前期反应的加速和后期反应的完善,提出了不同反应条件下的反应机理。
Reaction characteristics between hydroxy terminated polyethylene glycol (PEG) and isophorone di-isocyanate (EPDI) was observed with 13C-NMR accompanied by di-n-butylamine titration method. Zero-order reaction appeared when triphenyl bismuth (TPB) used as catalyst and reaction activities of-NCO groups were regardless to their position. Meanwhile a second-order reaction appeared when the reaction was catalyzed with dibutyltin dilaurate (DBTDL). The activities of -NCO groups in the later situation were apparently associated with their position. Combined application of TPB and DBTDL showed an additive results.suitable port-life and better network distribution hence will be benefited. Reaction mechanisms were schematically proposed.
出处
《北京理工大学学报》
EI
CAS
CSCD
1992年第S1期66-75,共10页
Transactions of Beijing Institute of Technology
