Polymerization of Cyclic Imino Ethers. VIII. Block Copolymers

Abstract

It was recently reported that poly(N-acyl ethyleneimines) when crystalline, have surfaces whose critical surface tension, γ_c, ranges from 24.5 dynes/cm. for a butyryl side chain to 22 dynes/cm. for hexanoyl and longer side chains (1). Thus, the polymer surface must be composed of close packed methyl groups. It was also found recently that poly(N-acyl trimethyleneimines) where the acyl group was relatively short have relatively high conductivities at 50% relative humidity. In static electricity decay tests, the charge half-life was between 5 and 0.5 seconds depending on the side chain (2). Since the polymerization is non-terminating (3) one could easily make block copolymers and investigate the manner in which the different components organize themselves. We therefore chose two polymers whose physical properties contrasted violently, as the candidates for block copolymers. These were poly(N-lauroyl ethyleneimine) [M.P.=150°C, γ_c = 22 dynes/cm., water insoluble (1,3)] and poly (N-acetyl trimethyleneimine) [amorphous, water soluble, Tg = 30°C, static decay half life ≃ 0.5 sec. (2,4)]. The polymerization reaction is given below.

This paper appeared in the Symposium on Block Copolymers as, “Block Copolymers of Cyclic Imino Ethers”, by M. Litt and J. Herz.

This research was performed at Allied Chemical Corporation, where the authors were employed at that time. We thank Allied Chemical for permission to present the work.