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ASTM D6338-17
Standard Classification System for Highly Crosslinked Thermoplastic Vulcanizates (HCTPV) Based on ASTM Standard Test Methods
This classification system covers highly crosslinked thermoplastic vulcanizates (HCTPV) for extrusion, molding and other fabrication methods. Highly crosslinked thermoplastic vulcanizates (HCTPV) are thermoplastic elastomers (TPE) consisting of two or more polymer systems at least one of which is rubbery and highly (>95 %) crosslinked and at least one of which is thermoplastic, with each system having its own phase. The thermoplastic phase will tend to be continuous and the rubbery phase discontinuous. The high level of crosslinking and ultrafine particle size (ca 1 m diameter) of the rubbery phase give rise to properties more closely approaching those of conventional thermoset rubber, when compared to the same thermoplastic/rubbery polymer composition with a lower level ( 95 %) of crosslinking. The HCTPV polymer compositions may contain fillers, reinforcing agents, plasticizers, resins, antidegradants, colorants and other beneficial constituents. Recycled HCTPV are not covered in this classification system.
ASTM International [astm]