Photocrosslinked Poly(ϵ‐caprolactone) – Polydimethylsiloxane – Poly(ϵ‐caprolactone) Triblock Copolymeric Films: Structural, Thermal and Shape Memory Properties

Abstract

AbstractThe shape memory triblock photocrosslinked copolymeric films of varying poly(ϵ‐caprolactone) (PCL) chain length and constant polydimethylsiloxane (PDMS) content are synthesized. The effect of PCL chain length on structural, thermal and shape memory properties of triblock copolymeric films is studied. The structural properties are analyzed by X‐ray diffraction (XRD) and optical microscope. Discrete crystal morphology is observed with increase in PCL chain length. Thermal properties are evaluated by differential scanning calorimetry (DSC) using non‐isothermal and isothermal modes. The crystallinity and crystal melting point of triblock polymer increases with increase in PCL chain length. The crystallization kinetics of triblock PCL‐PDMS‐PCL copolymeric films are studied with the help of Avrami model and Lauritzen‐Hoffman (LH) model. The three‐dimensional growth of PCL crystals is observed in triblock copolymers. Inclusion of PDMS block resulted in longer crystallization time, higher energy barrier and affects the crystal growth rate of PCL block, which further affect the shape fixity and shape recovery ratio accordingly.