Properties and preparation of thermoplastic polyurethane/silica hybrids using a modified sol–gel process

Abstract

AbstractThermoplastic polyurethane elastomer/silica hybrids (TPU/SiO2) were prepared using a modified sol–gel process. This modified approach used tetrahydrofuran (THF) to extract polysilicic acid from aqueous sodium metasilicate solutions. A THF or aqueous solution containing sol particles was mixed with TPU solution to form TPU/silica hybrids. The Fourier transform infrared (FTIR) spectra and dynamical mechanical properties were recorded to depict the interfacial interaction. Storage modulus increased due to the reinforcement of the in situ silica. Tear strength decreased significantly with increasing in situ silica content. Cutting strength decreased slightly due to crack tip confinement. The modified process with extraction showed improved mechanical properties and better optical properties than the conventional sol–gel process without extraction. The fracture surface was revealed through SEM (scanning electron microscopy) to observe the degree of SiO2 dispersion, which in turn confirmed the optical and mechanical property results. POLYM. ENG. SCI., 47:77–86, 2007. © 2007 Society of Plastics Engineers