Effect of Heat Sinks on Visco-Elastic & Mechanical Properties of EPDM Based Ablative Composites

Abstract

Ablative composites are heat shielding, protective materials that are being used in aerospace industry to protect inner hardware and sensitive devices. The aero dynamic vehicles have to face high stresses, ultra high temperature and adverse conditions of air friction. It is required to develop the materials with light weight and high modulus. EPDM, being heat and ozone attack resistant is the best candidate for the preparation of ablative composites by introducing different heat sinks such as silica, glass fiber, carbon fiber, asbestos, carbon and their combinations have been studied in this work. The prepared materials were tested and it was found that visco elastic behavior of the composites affected by the addition of reinforcing filler (carbon, silica), semi-reinforcing filler (carbon fiber, glass fiber) and non-reinforcing filler (asbestos powder). Mechanical properties tested at different rates, revealed the improvement in tensile strength and % elongation in case of reinforcing and semi-reinforcing fillers but showed adverse effect in case of non-reinforcing fillers. Rheological investigations of these novel composites shows that moony viscosity of the materials containing glass fiber, carbon fiber, silica decreases in the order glass fiber > carbon fiber > silica.

Effect of Carbon Black on Curing Behavior, Mechanical Properties and Viscoelastic Behavior of Natural Sponge Rubber-Based Nano-Composites

“…Compounding: Compounding is the mixture of rubber and other ingredients like curing agents, accelerators, cross linkers etc. [10]. Constituents were mixed on two roll mills consisting of two cylindrical-shaped hollow cast iron rolls having friction ratio 1.006 with the provisions for passing cold water through the rolls, which are attached with bull gear, gear box coupling and motor.…”

“…To obtain optimal foam expansion and good physical properties of the foams and optimal cross linking is the most critical requirement [9]. In this study, the Natural Rubber foams were prepared at temperature 150 o C, and different feeding ratios of the carbon black [5,10,15, 20 pphr (parts per hundred)]. The effect of reinforcing filler content on the cure behavior and mechanical properties of the foams was studied.…”