Economical preparation of fluorine‐containing thermoplastic elastomer with good phase miscibility and elasticity based on dynamic vulcanization

Abstract

Thermoplastic elastomers are a green and sustainable category of high performance polymers and show the great advantage of easy processability relative to conventional rubbers. In this work, a fluorine‐containing thermoplastic elastomer was prepared through dynamic crosslinking of poly(vinylidene fluoride)/poly(ethylene−methyl acrylate−glycidyl methacrylate) (PVDF/EGMA) blends with the aid of amino‐terminated crosslinker (KH602). The reaction kinetics of EGMA with KH602 were evaluated by the DSC Kissinger method with an activation energy (Ea) of 103.04 kJ mol−1. The increased ‘S‐type’ torque curve during dynamic crosslinking indicates the occurrence of chemical crosslinking while Fourier transform infrared spectra further demonstrate the dehydrofluorination of PVDF and the reaction between the amino group of KH602 and the epoxy group in EGMA. The prepared PVDF/EGMA (30/70) thermoplastic vulcanizate shows good reprocessability, mechanical robustness and elasticity. With increasing content of crosslinker, the stress at 300% increases from 2.3 MPa to 3.5 MPa while elongation at break decreases from 1150% to 380%. The PVDF/EGMA blend has a typical ‘sea‐island’ morphology with ca 7 μm dispersed phase while PVDF/EGMA thermoplastic vulcanizates have gradually elongated disperse phases due to improved interfacial miscibility as evidenced by quantitative nanomechanical mapping AFM modulus analysis. Therefore, dynamic vulcanization is an effective and economical approach to integrate thermoplasticity and rubber elasticity into plastic/rubber pairs with good phase miscibility. © 2023 Society of Industrial Chemistry.