Investigations on "near perfect" poly(2-oxazoline) based amphiphilic polymer conetworks with a crystallizable block

Amphiphilic polymer conetworks (APCNs) of "near perfect" structure were prepared by cross-linking defined poly(2-oxazoline)-based block copolymers. To this end, ABA triblock copolymers with poly(2-methyloxazoline) (PMOx) as A block and poly(2-heptyloxazoline) (PHepOx) as B block in different compositions and with different cross-linkable end groups were prepared and crosslinked. The resulting amphiphilic polymer conetworks were characterized with atomic force microscopy (AFM) and small as well as wide angle X-ray scattering (SAXS/WAXS). The results show that the PHepOx block crystallizes in the APCNs if the content is larger than 19 vol.%, but shows no thermal signature in the differential scanning calorimetry if the polymer content is below 68 vol.%. Further, the size of the polymer phase is the same in a composition range of 38-58 vol.% PHepOx. The phase size was confirmed by AFM. The found very regular interconnected structure over a wide range of compositions seems to be the generic structural motive in APCNs and is also formed when inserting a crystallizable polymer block. (C) 2016 Elsevier Ltd. All rights reserved.