Solvent Content Controlling Strategy for Cocrystallizable Polyesters Enables a Stress‐Free Two‐Way Shape Memory Effect with Wider Service Temperatures

Abstract

Abstract​It is challenging to enhance the stress‐free two‐way shape memory (stress‐free TWSM) effect to obtain a wide range of response temperatures. Herein, a polycaprolactone (PCL)/poly(ω‐Pentadecalactone) (PPDL) was photocured under UV light irradiation in the solvent of 1,1,2‐trichloroethane (TCA), to obtain a series of cross‐linked polyesters (CPES). Controlling solvent content (SC) which was removed after the polymerization allows the yielded CPES to perform a regulatable thermodynamic and stress‐free TWSM properties. High SC is beneficial to reduce the degree of chain overlap (C/C*) of PPDL chain segments in the PCL‐based CPES network, then causes the co‐crystallization of PCL and PPDL and yielding an additional melting‐transitions (Tm). An enhanced stress‐free TWSM was obtained in high SC samples (CPES‐15‐90), reflected in the attainment of a wide range of response temperature, which mean a wider service temperature. The enhancement is reflected in higher reversible strain of high SC samples compared with the samples prepared with low SC when varying high trigger temperature (Thigh). Even at high Thigh, the High SC sample still has reversible strain. Therefore, controlling solvent content strategy for photocuring co‐polyester not only provides a new preparation approach for high‐performance SM polymers, but also offers new condensed polymer structure to explore.This article is protected by copyright. All rights reserved