Effects of environmental aging on physical properties of aromatic thermosetting copolyester matrix neat and nanocomposite foams

Abstract

This paper focuses on the effects of cyclic water immersion and salt spray aging tests on the physical properties of aromatic thermosetting copolyester (ATSP) matrix. Neat and graphene nanoplatelet (GNP) incorporated nanocomposite ATSP foam morphologies are employed to have enhanced surface areas exposed to the surrounding aqueous media, via porous configurations, which deliberately aggravate the extent of the aging on the matrix. The ATSP foams are fabricated through a thermal condensation polymerization process. Upon exposures to the periodic aging conditions, ATSP demonstrates an adsorption-regulated mass uptake mechanism. Contact angle measurements reveal GNP-neutral and hydrophobic characteristics for the ATSP matrix. Microstructural imaging exhibits no substantial physical degeneration in the matrix caused by the accelerated aging conditions. Glass transition temperatures of both neat and nanofiller incorporated ATSP forms display only marginal decreases stemmed from small volumes in the matrix occupied through the hygroscopic swelling. Thermal degradation stability of the ATSP morphology is effectively preserved following the aging processes. Compressive mechanical strengths of the foams lie within the regime of their virgin (not exposed to the aging conditions) counterparts yet show slight reductions. The ATSP matrix demonstrates an outstanding aging resistance to the subjected environments which can potentially address high-performance requirements in cutting-edge industrial applications. © 2017 Elsevier Ltd