Dijkstra - Primary Chemical Sequence Ultimately Determines Crystal Thickness in Segmented All-Aliphatic Copolymers

Yaroslav I. Odarchenko, Denis V. Anokhin, David Doblas,Martin Rosenthal, Jaime J. Hernandez, Loic Vidal, Niels J. Sijbrandi, Ad J. Kimenai, Edwin P. C. Mes, René Broos, Georg Bar, Pieter J. Dijkstra, Jan Feijen, Mikhail Soloviev, and Dimitri A. Ivanov

Macromolecules 2013

Abstract

Thermoplastic elastomers (TPEs) are known to exhibit a phase-separated morphology which depends on their chemical structure and processing. The design of novel TPEs with predefined properties which are also independent of the material thermal history has so far remained a challenge. The focus of this work is on the semicrystalline morphology of allaliphatic thermoplastic elastomers consisting of alternating polytetrahydrofuran (PTHF) segments and uniform glycine or β-alanine bisoxalamide units. The thickness of the hard segment crystals was found to be highly monodisperse and independent of the sample thermal history. Using Nanocalorimetry, we observed that at cooling rates as high as 12 000 °C s−1 the bisoxalamide segments can still crystallize although the crystallization temperature decreases by ca. 26 °C.