HP/HT Hot-Wet Resistance of Thermoplastic PEEK and Its Composites

Abstract

AbstractAdvanced thermoplastic polyetheretherketone (PEEK) resin is known to have excellent resistance to elevated-temperatures in a broad range of severe chemical environments. One of the most challenging oilfield downhole environments for most engineering polymers is the high-pressure/high-temperature (HP/HT) hot-wet environment. PEEK resin is proven to be capable of resisting steam and water environments at elevated temperatures above 400°F because of its thermoplastic polyetherketone polymer chemistry and semi-crystalline polymer structure. However, when various reinforcement phases are incorporated in the PEEK resin to form PEEK matrix composites, their HP/HT hot-wet resistant capabilities can be very different, depending on the type of reinforcement, the resin-reinforcement interface bonding and the reinforcement geometry. A clear understanding of the HP/HT hydrolysis resistant behavior of the PEEK resin and its composites and the related mechanisms is critical.In this study, virgin PEEK resin and its glass-filled composites were investigated, including 30% glass-fiber and 30% glass-bead filled PEEK grades. The hot-wet degradations studied included hygrothermal material structural damage, moisture-induced thermal mechanical degradation and hydrolytic reactions. The experimental methods involve HP/HT hot-wet environmental exposure in NaCl brine up to 400°F and 5,000 psi, mechanical testing and dynamic mechanical thermal analysis before and after the HP/HT hot-wet exposure. Experimental results and data analysis will be presented. Deformation and failure mechanisms are also discussed.KeywordsThermoplastic PEEKGlass-filled PEEK compositesHot-wet resistanceHydrolysisMechanical testsDynamic mechanical thermal analysisInterface debonding