Highly loaded particle doped thermoset composites with improved mechanical properties

Abstract

This invention relates to highly loaded particle doped composites based on thermosetting polymer systems in which the sequential addition of particles of certain size distribution is followed by curing and casting of the slurry to form a thermoset composite. Conventionally, at a threshold of beyond 90% of particles by weight of the polymer using castor oil, the mechanical properties of the said composite exhibit a sharp decline. The present invention mitigates this behavior by incorporating a unique combination of cross-linking agent and chain extension in the base polymer to impart exceptional mechanical properties to the said thermoset composite. More specifically, the base polymer consists of hydroxy-terminated polybutadiene (HTPB), with castor oil as cross-linking agent and butane / hexane diol as the chain extension precursors. An added advantage according to the present invention resides in the analytical nature of HTPB as opposed to the castor oil natural product; traditional composites based on castor oil are hampered by its inconsistent chemical composition and poor shelf life in the fabricated composite. The thermoset composite according this invention exhibits superior tensile strength (200-300 psi) and elongation (ca. 100-150%) in composites using trimodal particle loading as high as 92% by weight of the thermoset composite.