Preparation, microstructure, and microstructure-properties relationship of thermoplastic vulcanizates (TPVs): A review

It is common practice to blend polymers to obtain high-performance polymer materials for new applications. Thermoplastic vulcanizates (TPVs), consisting of a high content of crosslinked rubber as a dispersed phase and a low content of thermoplastic as a continuous phase, are usually prepared by pre-blending rubber and plastic phases followed by dynamic vulcanization. They are a special class of high performance thermoplastic elastomers (TPEs) as they combine both the excellent elasticity and mechanical properties of crosslinked rubbers and good processability and recyclability of thermoplastics. As such, in the recent decades they have attracted much attention and have become the fastest growing elastomers to replace unrecyclable thermoset rubbers. This review focuses on recent progresses in TPVs, and more specifically on the following issues: (1) preparation methods of TPVs, (2) mechanisms of formation of the microstructure of TPVs; (3) relationships between the microstructure and properties, (4) review of various types of TPVs, including general TPVs, special TPVs, bio-based TPVs, and TPVs-based nanocomposites, (5) future challenges on TPVs.