Carbon fiber reinforced polyethylene composite adhesive at elevated temperatures

Abstract

The development of multi-layer-multi-material thermoplastic structures necessitates the bonding of dissimilar materials with varying mechanical, chemical, barrier, and thermal properties. Thermoplastic adhesives, such as maleic anhydride grafted polyethylene (PE-MAH), are advantageous over thermoset adhesives given their similar manufacturability, and numerous benefits as sustainable materials in compliance with strict environmental regulation in construction, automotive, and energy industries. A key drawback is that PE-MAH demonstrates weak adhesive properties at elevated temperatures. In this study, the adhesion strength of carbon fiber (CF) reinforced PE-MAH at elevated temperatures were evaluated using a novel method of T-peel test under a controlled environment. Significant improvements of 71% and 295% increase in peel strength at 90 °C and 110 °C, respectively, were achieved with CF reinforcement over neat PE-MAH. The improving mechanisms were discussed on both macro-level, i.e., enhanced peel zone and eliminating crazing, and micro-level, i.e., transferred stress and dispersed energy into micro peel zones. This study demonstrates the efficacy of tailoring the adhesion strength of thermoplastic composite adhesive for significantly improved performance at elevated temperatures.