Environmental Study of Nano-Filler Embedded Fiber Reinforced Polymer Composite

Abstract

Fiber reinforced polymer (FRP) composites have a huge demand for applications in diversified fields due of their unique combination of properties. Inspite of having many advantages, these composites are susceptible to degradation when exposed to harsh environmental conditions which limits their use. CNTs have proved to be an ideal and most suitable reinforcing element to manufacture advanced materials i.e nanocomposites. GFRP composites were fabricated with 0.1wt%, 0.3wt%, and 0.5wt% CNT. A low wt.% CNT up to 0.3% showed significant increase in mechanical properties such as flexural strength, ILSS, Storage modulus of GFRP due to better fiber/matrix interfacial bonding whereas a higher wt.% CNT showed not much improvement due to agglomeration of CNTs in the matrix. During the fabrication, period of service and storage of components made up of these polymer materials, they are operating under changing environments which affects the predictability and reliability of the long term as well as the short term properties and also their in-service performance. This work is also an attempt to highlight the degradations that may be caused to the GFRP as well as CNT reinforced GFRP composites on exposing to various environmental conditions such as UV radiation, 95% RH at 60C and Hot Water at 60C. Short beam shear test as well Dynamic Mechanical Analysis of conditioned samples in all the three cases showed a significant decrease in mechanical properties of the composite systems. There was also a very slight increase in the glass transition temperature due to these exposures. DMA study was conducted on all the composite systems with an isothermal holding at 90C and 110C with different holding time periods and their behaviour were analysed. Incorporation of a low wt.% CNT reinforcement is found to lessen the degradation effect of the exposure environment on the polymer matrix and 0.3wt% CNT-GE composite demonstrated an overall better performance under all kinds of exposure.