Effect of Thermal and Microwave Treatment on Low Temperature Mechanical Property of Glass Fiber Reinforced Polymer Composite: An Experimental Exploration

Abstract

There has been a tremendous advancement in the science and technology of fiber reinforced polymer composites (FRP) in recent times. The low density, high strength, high stiffness to weight ratio, excellent durability, and design flexibility of fiber reinforced polymers are the primary reasons for their use in many structural components in the aircrafts, automotive, marine, transportation, sports, medical science and more recently the building and construction industries and particularly in areas that are weight and corrosion sensitive. A recent example is the Bridge-in-a-Backpack for 2014 Winter Olympics in Russia, an innovative inflatable composite-concrete arch bridge, which was developed to reduce construction time and costs, increase lifespan, reduce maintenance costs and reduce the carbon footprint of bridge construction1. But the phenomenon of the occurrence of their fracture and failure at low temperatures and under varying loading rates is a quite complex, and is not easily understandable phenomenon, because of the various types of the failure modes involved (e.g. delamination sites, debonding, fiber pullout regions, crack propagation front, striations and bubble bursting in the matrix). Thus a critical study has to be made to understand the overall phenomenon. Recently an active area of investigation related to this work is being explored by Temperature Modulated Differential Scanning Calorimetry (TMDSC) and Fourier Transform Infrared Spectroscopy (FTIR-Imaging), techniques to find out the possible causes for failure of the composite. In the present study, an attempt has been made for fractographic study of the composite material using SEM micrographs of the fractured surfaces of composites under Thermally Conditioned and post curing by Microwave treatment, followed by their exposure in ultralow temperatures, so that the origin of the crack could be analyzed and the factors affecting the locus of initiation of fracture could be determined. This would be followed by FTIR-Imaging and TMDSC to determine the alternation and deviation of Stoichiometry and the Tg values respectively, to have a better idea about the failure phenomenon.