SYNTHESIS AND PERFORMANCE EVALUATION OF SOYBASED ALIPHATIC POLYURETHANE NANOCOMPOSITES FOR PULTRUSION

摘要

Polyurethane (PU) resin systems are generally characterized as aromatic and aliphatic. AliphaticPU has lower mechanical properties than the aromatic resin system due to its chemical structure.The objective of the present work is to improve the mechanical properties of aliphatic resinsystem by exfoliating silicate nano particles. A pultrudable, soy-based, polyol-isocyanatealiphatic resin has been used as the base system. Nanocomposites were synthesized using thebase resin and modified montmorillonite (MMT) clay. Modification of Na-MMT was confirmedby Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopyanalyses. Increase in the basal spacing of the nanoclay was observed by wide angle X-raydiffraction. The curing mechanism of soy-based PU resin with 1wt% of triethanol amine/methyliodide exchanged MMT clay was studied using differential scanning calorimetry as well asFTIR. Tensile testing of the nanocomposites showed improved modulus when compared to theneat aliphatic resin system. Soy-based nanocomposites hold great promise as environmentallyfriendly and low cost materials for structural and automotive applications.