Acrylic-Based Polyurethane/Silica Hybrids Prepared by Acid-Catalyzed Sol–Gel Process: Structure and Mechanical Properties

✍ Scribed by Guodong Chen; Shuxue Zhou; Guangxin Gu; Limin Wu

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 344 KB
• Volume: 206
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200400478

✦ Synopsis

Abstract

Summary: Silica sols were first prepared based on different ratios of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) by an acid‐catalyzed sol–gel process, and then incorporated into acrylic‐based polyurethanes. The structures and morphologies of silicone‐oxo clusters were studied by ^29^Si NMR, SAXS, and scanning electron microscopy (SEM), whereas the mechanical properties of polyurethane/silica hybrids were characterized by DMA and tensile tests. The silicone‐oxo clusters in both silica sol and polyurethane hybrids became denser and larger at a higher molar ratio of TEOS/MTES and higher silica content, and the silica‐oxo clusters of polyurethane/silica hybrids even became more compact and larger than those of silica sols, increasing the elastic modulus and tensile strength of polyurethane/silica hybrids.

Typical structure of silica sol prepared from the hydrolysis and condensation of TEOS and MTES with acid as the catalyst.

magnified imageTypical structure of silica sol prepared from the hydrolysis and condensation of TEOS and MTES with acid as the catalyst.