styrene-isoprene-styrene
Quick Summary
Styrene-isoprene-styrene (SIS) is a type of triblock copolymer. It features polystyrene segments at both ends of a molecular chain, with an isoprene segment in the middle. This structure makes SIS a thermoplastic elastomer, combining the elasticity of isoprene rubber with the moldability of polystyrene.12
In SIS, the polystyrene end-blocks form small domains, creating clusters of hard polystyrene within a network of flexible polyisoprene. While less resilient than vulcanized rubber, SIS materials are strong at room temperature and can be easily processed and reprocessed due to the thermoplastic nature of polystyrene. Common applications include hot-melt adhesives and as an additive to improve bitumen properties.12
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