Environmental Durability assessment of CNT enhanced GFRP composites

Abstract

Fiber reinforced polymer (FRP) Composites are being used globally in many structural applications due to their superior specific properties. The in-plane mechanical performance of such FRP composite to a large extent is governed by the fibers. However, the out-of-plane response gets substantial contribution from the matrix and/or interfaces. In this regard, to improve the out-of-plane performance of such laminated composites, CNT incorporation has been found to be beneficial. Further, the performance of such CNT filled FRP composites in various environments is an active field of research. However, it has always been a curious concern to predict the long term behavior of such materials in real inservice applications. And, doing it under the exact conditions for such a long time period (like years) in laboratory scale is quite cumbersome. The long-term creep performance of these composites gives us an idea about the life-time of such materials in the real field of application. In this article, an attempt has been taken to predict the long-term creep performance of glass fiber reinforced polymer (GFRP) composite with and without CNT reinforcement using time temperature super-position (TTSP) principle. Step-wise (with 5°C step size) isothermal creep and recovery tests were performed using DMA (Netzsch DMA 242E) in the temperature range of 30°C – 120°C with a constant creep load (corresponding stress was 40 MPa). At each temperature both creep and recovery were performed for 1 hr each. Results indicated that Creep temperature has a decisive role to play on the interfacial stress transfer of the CNT/polymer composites and hence on the long-term durability of CNT embedded GFRP Composites