|Interesting Performances of Newly Designed SIS Block Copolymers
Elastomer & C5 Chemicals, R&D Center, Zeon Corporation, Kawasaki, Kanagawa, Japan
Nippon Gomu Kyokaishi,(2006),79(9),443-447 General Review in Japanese
Polystyrene-block-polyisoprene-block-polystyrene (SIS) block copolymers are used mainly in hot melt pressure-sensitive adhesives (HMPSA), because their softness and elasticity can give proper tackiness and well-balanced adhesive properties. However, SISs are not used for molded elastic articles, such as elastic sheets or films, while they are quite soft and elastic.
We have developed SISs with a new design factor. Some of them show unique properties as thermoplastic elastomers.
The SISs containing "Polyisoprene Mono-block" with low molecular weight, have some interesting performances. They are sticky and very soft polymers without tackifier resins or plasticizers and show excellent tension set properties. Furthermore, they show high loss tangent in dynamic viscoelasticity test and could improve damping properties.
SIS block polymers have been also developed to show excellent transparency by reducing their impurities.
They would have some potential for elastic articles, such as elastic sheets or films.
SIS block copolymer, Sticky, Loss tangent, Damping, Transparency