Natural and acid-treated attapulgite reinforced soybean oil-based polyurethane/epoxy resin interpenetrating polymer networks

Abstract

Soybean oil-based polyurethane (PU)/epoxy (EP) interpenetrating polymer network (IPN) nanocomposites were prepared with natural attapulgite (N-ATT) and acid-treated attapulgite (A-ATT). The structure, glass transition, damping properties, thermal stability, mechanical properties and morphology of PU/EP IPN/ATT nanocomposites were characterized by X-ray diffraction (XRD), dynamic mechanical analysis (DMA), thermogravimetric analyzer, universal test machine and scanning electronic microscope (SEM). XRD showed that interaction with PU did not change the crystal structures of ATT. DMA results revealed the addition of ATT improved the glass transition temperature of the soybean oil-based PU/EP IPN, especially for A-ATT. However, the incorporation of ATT slightly decreased the damping properties of the soybean oil-based PU/EP IPN. Tensile tests confirmed that A-ATT had a significant reinforcement effect on the soybean oil-based PU/EP IPN. The tensile strength of the soybean oil-based PU/EP IPN increased by 56% with the addition of 4 mass% A-ATT. SEM demonstrated the relatively uniform dispersion of both N-ATT and A-ATT in the soybean oil-based PU/EP IPN matrix.