Toughening Clear Polypropylene Copolymers with Styrenic Block Copolymers

摘要

1. Styrenic block copolymers with modified midblocks have very good compatibility and clarity in rPP and have very good blush resistance in rPP. Clarity increases with the loading of the block copolymer. One can make very clear flexible rPP compounds which make good candidates to replace plasticized PVC. Impact resistance is good down to around -10C at 20 wt% loadings which is better than the conventional PE metallocene used in clear rPP. 2. For even better low temperature impact resistance (-20C) while maintaining clarity, an experimental styrenic block copolymer works best at a loading of 20 wt%. 3. Notched Izod impact at room temperature for the styrenic block copolymers is very good and is better than the PE metallocenes used to impact modify clear rPP.