Premium
Morphology‐controlled multiple one‐ and two‐way shape‐memory behavior of cross‐linked polyethylene/poly(ε‐caprolactone) blends
Author(s) -
Kolesov Igor,
Dolynchuk Oleksandr,
Borreck Sven,
Radusch HansJoachim
Publication year - 2014
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.3338
Subject(s) - materials science , crystallization , crystallinity , polymer blend , composite material , phase (matter) , polymer , isothermal process , chemical engineering , copolymer , thermodynamics , organic chemistry , chemistry , physics , engineering
The capability of phase morphology of covalent networks on the basis of crystallizable polymer blends to control their multiple shape‐memory (SM) behavior was proven, especially for invertible two‐way SM effect, which is observed as an anomalous elongation of a sample under constant load during the non‐isothermal crystallization. In order to achieve a triple‐shape one‐ and two‐way behavior, a set of binary blends with different contents of high‐density polyethylene and poly(ε‐caprolactone) and one 50/50 blend of ethylene–octene copolymer and trans‐polyoctenamer cross‐linked by peroxide were prepared. The considerable enthalpic effects in temperature ranges of crystallization and melting of both blend components point to possible softening/hardening of discussed blends caused by non‐isothermal melting/crystallization at heating/cooling, respectively. The two‐way SM behavior was investigated in tensile mode under constant load during cooling and heating sequentially. It is quite obvious that the distinct manifestation of triple‐SM behavior is possible only when a continuous phase of blend has lower crystallization/melting temperatures in comparison with dispersed phase. By contrast, if crystallization/melting temperatures of dispersed phase are lower, then its ability to change a shape is suppressed by already solidified continuous phase. Obtained results allow conclude the following: first, the performances of both one‐ and two‐way SME are enhanced with increasing cross‐link density and crystallinity of polymer network as well as due to selection of optimal load; second, the key to improve the multiple SM behavior of polymer blends is further optimization of their phase morphology, especially better separation/decoupling of blend phases. Copyright © 2014 John Wiley & Sons, Ltd.