Reactive compatibilization of zinc dimethacrylate on dynamically vulcanized thermoplastic polyurethane/silicone rubber blends

Abstract

AbstractThermoplastic polyurethane (TPU)/silicone rubber (SR) thermoplastic vulcanizates (TPVs) are considering to be a promising material for smart wearable technologies due to its low temperature and high temperature resistance and biological affinity. However, the poor compatibility between TPU and SR phases limits its practical application. In this paper, TPU/SR TPVs were prepared through dynamic vulcanization and zinc dimethacrylate (ZDMA) was used to improve the interface between TPU and SR phases. FTIR results and theoretical calculation showed that complex reactions including the graft‐polymerization of ZDMA occurred onto the main chains of TPU and SR in the presence of peroxides to form a strong interface and improve the compatibility. Dynamic mechanical analysis implied the difference of glass transition temperature of the two phases reduced from 86.4 to 67.3°C with the addition of 5 wt% of ZDMA compared to original TPVs. Scanning electron microscope showed that with the addition of 5 wt% ZDMA, the crosslinked SR phase formed a network structure when TPU phase was etched with dimethyl sulfoxide. By adding 5 wt% of ZDMA, the torques during mixing, tensile strength, and tear stress of TPVs were improved by 150%, 273%, and 217% respectively, compared to the TPVs without ZDMA.Highlights The compatibility between TPU and SR was improved by adding ZDMA. The mechanism for ZDMA enhancing the interface of TPU/SR TPVs was discussed. The addition of ZDMA improves the mechanical properties of TPU/SR TPVs. An appropriate loading of ZDMA used for TPU/SR TPVs was discussed.