Nanoscale reinforcement of polyhedral oligomeric silsesquioxane (POSS) in polyurethane elastomer

✍ Scribed by Fu, Bruce X; Hsiao, Benjamin S; White, Henry; Rafailovich, Miriam; Mather, Patrick T; Jeon, Hong G; Phillips, Shawn; Lichtenhan, Joseph; Schwab, Joseph

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 109 KB
• Volume: 49
• Category: Article
• ISSN: 0959-8103
• DOI: 10.1002/(sici)1097-0126(200005)49:5<437::aid-pi239>3.0.co;2-1

✦ Synopsis

A unique class of polyurethane (PU) elastomer containing inorganic molecules (polyhedral oligomeric silsesquioxane, POSS) as molecular reinforcement in the hard segment was investigated by means of wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) techniques. WAXD results indicate that POSS molecules form nanoscale crystals showing distinct re¯ection peaks. The formation of POSS crystals is probably prompted by the microphase separation between solid-like hard segments and rubbery soft segments in PU. The microphase separation of hard and soft segments was observed by SAXS, which shows a long period of 111 A Ê for 34 wt% POSS-PU and 162 A Ê for 21 wt% POSS-PU, and hard segment domains with sizes of about 34 A Ê for both of them. WAXD results from a series of POSS compounds with a corner substituted by a functional group of varying length were compared with POSS-PU, which also con®rms the presence of nanoscale POSS crystals in the polymer matrix.