Physical properties of poly(tetrahydrofuran)-block-poly(2-ethyl-2- oxazoline) triblock copolymer

Abstract

ABA-type triblock copolymers (PEOxz-PTHF-PEOxz) composed of poly(tetrahydrofuran) (PTHF) and poly(2-ethyl-2-oxazoline) (PEOxz) were synthesized by cationic sequential polymerization. Differential scanning calorimetry and wide-angle X-ray diffraction analyses revealed that PEOxz-PTHF-PEOxzs produced a microphase separation structure, which consisted of a partially crystallized amorphous PTHF phase containing PEOxz chains on both ends. Tensile testing showed that PEOxz-PTHF-PEOxz exhibited tough mechanical properties that differed from those of the brittle PTHF homopolymer. Thus, it was suggested that the amorphous PTHF/PEOxz phase played a role in physically cross-linking the moieties via entanglement, resulting in a PEOxz-PTHF-PEOxz material with tough mechanical properties and the ability to be cold-drawn. Copyright © 2013 The Society of Polymer Science, Japan.