Portal de Periódicos da CAPES

Synthesis and thermal properties of hybrid copolymers of syndiotactic polystyrene and polyhedral oligomeric silsesquioxane

2002; Wiley; Volume: 40; Issue: 7 Linguagem: Inglês

10.1002/pola.10175

1099-0518

Lei Zheng, Rajeswari M. Kasi, Richard J. Farris, E. Bryan Coughlin,

Synthesis and characterization of novel inorganic/organometallic compounds

Abstract Copolymerizations of styrene and the polyhedral oligomeric silsesquioxane (POSS)–styryl macromonomer 1‐(4‐vinylphenyl)‐3,5,7,9,11,13,15‐heptacyclopentylpentacyclo [9.5.1.1 3,9 .1 5,15 .1 7,13 ] octasiloxane have been performed with CpTiCl 3 in conjunction with methylaluminoxane. Random copolymers of syndiotactic polystyrene (sPS) and POSS have been formed and fully characterized with 1 H and 13 C NMR, gel permeation chromatography, differential scanning calorimetry, and thermogravimetric analysis. NMR data reveal a moderately high syndiotacticity of the polystyrene backbone consistent with this use of CpTiCl 3 as a catalyst and POSS loadings as high as 24 wt % and 3.2 mol %. Thermogravimetric analysis of the sPS–POSS copolymers under both nitrogen and air shows improved thermal stability with higher degradation temperatures and char yields, demonstrating that the inclusion of the inorganic POSS nanoparticles makes the organic polymer matrix more thermally robust. The polymerization activity and thermal stability are also compared with those of reported atactic polystyrene–POSS copolymers. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 885–891, 2002; DOI 10.1002/pola.10175