Thermal insulation by heat resistant polymers for solid rocket motor insulation

Abstract

A new method for the development (design, fabrication, and characterization) of asbestos-free rubbers for use as rocket motor insulators is presented. Such insulation is based on chopped carbon fiber (CCF) and aramid fiber in pulp form asreinforcement for ethylene propylene diene monomer (EPDM) along with ammonium polyphosphate (AP) flame retardant agent. Six millimeters long CCFs and/or Kevlar pulp (KP) are dispersed in the EPDM polymeric matrix to obtain a homogenous master batch for curing. The new method involves the development of two types of prepregs andthe lamination of these types of prepregs. The first one consists of CCF/EPDM/AP (50 phr CCF) and the second type of prepreg KP/EPDM/AP (30 phr KP). Laminates composed of six alternative layers of these prepregs have been shown to exhibit better thermal, mechanical, physical, and ablative properties than their non-laminated counterparts.