Compatibilization of polypropylene–polystyrene blends: Part 2, crystallization behavior and mechanical properties

✍ Scribed by Akin A. Adewole; Anthony Denicola; Costas G. Gogos; Leno Mascia

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 510 KB
• Volume: 19
• Category: Article
• ISSN: 0730-6679
• DOI: 10.1002/1098-2329(200023)19:3<180::aid-adv3>3.0.co;2-h

✦ Synopsis

Reactor produced blends of polypropylene (PP) and polystyrene (PS) are obtained by graft copolymerization of styrene onto polypropylene chains. This technique generates simultaneously a graft copolymer (PP-g-PS) and polystyrene homopolymer. The resulting blends, however, have a low impact resistance and have to be modified with the addition of rubbery toughening agents, such as an ethylene propylene copolymer (EPR) or a styrene-b-ethylene-alt-butylene-b-styrene (SEBS) triblock copolymer, in a downstream compounding operation. Part 1 of this work, which has been accepted for publication in the British Journal "Plastics, Rubber, and Composites", was concerned with the compatibilization efficiency and the effect of mixing intensity on the morphological and rheological properties. Part 2 of the study deals with interactions of the components of the blends. These interactions were assessed by monitoring the crystallization behavior and mechanical properties. Mixing experiments were conducted on a proprietary twin screw mixing element evaluator (TSMEE) and also on a commercial TSE-30