Mechanical and Swelling Properties of Hydroxyl-Terminated Polybutadiene-Based Polyurethane Elastomers

摘要

The mechanical and swelling properties of an elastomeric polyurethanes have been studied. The elastomers were composed of hydroxyl-terminated polybutadiene, the chain extended with either glyceryl monoricinoleate, neopentyl glycol, trimethylolpropane and cured with toluene diisocyanate and 4,4'-methylene diphenyldiisocyanate. The mineral fillers under study were nanoclay, TiO2, ZrO2 and ZnO. Gel fraction, crosslinking degree and average molecular weight between crosslinks were calculated from the swelling data. The hydrogen bonding index, which is a measure of hydrogen bonding, was calculated from infrared spectrophotometric data. The most remarkable result was that crosslink density diminished for a nanoclay polyurethane nanocomposite compared to an unfilled sample. Samples with nanoclay exhibited an unusual inverse correlation between crosslink density and tensile strength. Our findings showed that nanoclay in particular is an effective inorganic filler that can modulate the microstructural and mechanical behavior of polyurethane elastomers for tuned applications.