Ethylene–Propylene–Silsesquioxane Thermoplastic Elastomers

✍ Scribed by Bradley Seurer; E. Bryan Coughlin

• Book ID: 102485731
• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 265 KB
• Volume: 209
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200800065

✦ Synopsis

Abstract

Preparative methods for the incorporation of polyhedral oligomeric silsesquioxane (POSS) macromonomers into ethylene–propylene (EP) polymers have been developed that utilize metallocene polymerization. Analysis of these novel ethylene–propylene–POSS polymers using wide‐angle X‐ray diffraction reveals that pendant POSS groups off the polymer backbones aggregate with a phenyl periphery, and the polymers crystallize as anisotropically shaped nanocrystals. POSS particle aggregation is strongly dependent on the nature of the POSS peripheral group. X‐Ray studies suggest that aggregation of POSS in the EP elastomers did not occur with isobutyl and ethyl peripheries, as they disperse within the polymer matrix. The formation of POSS nanocrystals increases the mechanical properties of these thermoplastic elastomers. The tensile storage modulus increases significantly with the addition of POSS, as does the length of the rubbery plateau region. Tensile studies reveal an elongation at break of 720% for one EP‐phenyl POSS polymer sample, with the others between 400 and 500%.

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