Polymer, Vol.121, 312-319, 2017
Asymmetric supramolecular double-comb diblock copolymers: From plasticization, to confined crystallization, to breakout
The combination of asymmetric P4VP-b-PAPI diblock copolymers (i.e. f(P4VP) not equal f(PAPI)) and 3-NDP surfactants in hydrogen-bonded [poly(4-vinylpyridine)-block-poly(N-acryloylpiperidine)](3-nonadecylphenol) x (P4PA(3NDP)(x)) supramolecular double-comb diblock copolymers could potentially result in rather interesting morphologies. However, plasticization of the copolymer and the ability of 3-NDP to crystallizewere found to affect their self-assembly significantly. In general, for high comb densities x, the complex's tendency to crystallize and its preference to forma flat interface dominated microphase separation. Lower values of x on the other hand gave uneven distribution of 3-NDP, resulting in a higher glass transition temperature of the P4VP block. Crystallization of 3-NDP's aliphatic tailswas therefore in most cases restricted to the preferential PAPI microdomains, thereby maintaining the large length scale block copolymer morphology that was already present in the melt. Such behavior is identical to self-assembly of linear semicrystalline diblock copolymers, as in these type of systems structure formation depends on the segregation strength and relative magnitude of the order-disorder transition (T-ODT), T-g and T-c, leading to mechanisms like confined crystallization or breakout. (C) 2017 Elsevier Ltd. All rights reserved.
Keywords:Double-comb diblock copolymers;Supramolecular interactions;Confined crystallization;Breakout;Semicrystalline copolymers