Nanoscale Boehmite Filler for Corrosion- and Wear-resistant Polyphenylenesulfide Coatings

Abstract

We evaluated the usefulness of nanoscale boehmite crystals as a filler for anti-wear and anti-corrosion polyphenylenesulfide (PPS) coatings exposed to a very harsh, 300°C corrosive geothermal environment. The boehmite fillers dispersed uniformly into the PPS coating, conferring two advanced properties: First, they reduced markedly the rate of blasting wear; second, they increased the PPS's glass transition temperature and thermal decomposition temperature. The wear rate of PPS surfaces was reduced three-fold when 5 wt% boehmite was incorporated into the PPS. During exposure for 15 days at 300°C, the PPS underwent hydrothermal oxidation, leading to the substitution of sulfide linkages by sulfite linkages. However, such molecular alteration did not significantly diminish the ability of the coating to protect carbon steel against corrosion. In fact, PPS coating filled with boehmite of ≤ 5 wt% adequately mitigated its corrosion in brine at 300°C. One concern in using this filler was that it absorbs brine. Thus, adding an excess amount of boehmite was detrimental to achieving maximum protection.

An application‐oriented roadmap to select polymeric nanocomposites for advanced applications: A review

“…Boehmite is aluminum oxide hydroxide [AlO(OH)] generally used as nanofillers for polymers to enhance mechanical properties and other novel properties such as corrosion and wear resistance coatings, suppressing flammability of PU foams, proton exchange membranes, smart hydrogels, and so on . The preparation methods for boehmite can be divided into four groups: in situ synthesis, template synthesis, melt intercalation (melt blending) techniques, and intercalation of polymer from solution .…”

Research and Development on Coatings and Paints for Geothermal Environments: A Review

“…Further studies from the same group [113,114] aimed at removing the step of ACA-to-bohemite transformation by incorporating nanoscale bohemite phase directly in the as-deposited paint system. The study focused on characterizing the resistance to erosion wear, thermal properties, and analysis of surface phases and morphology after exposure to CO 2 -rich geothermal brine at 300 °C for 15 days.…”

“…Porosity is generated within the paint layer in contact with the exposure medium, which was linked to an excessive amount of bohemite phase. Reproduced with permission [113]. Copyright 2004, SAGE Publications Inc.…”

Experience with the Development of Advanced Materials for Geothermal Systems

“…To meet these material criteria, BNL developed smart, high-performance polyphenylenesulfide (PPS)-based composite coating systems consisting of PPS as the matrix, polytetrafluoroethylene (PTFE) as the antioxidant 12 ' 13 , micro-scale carbon fiber as the thermal conductor and reinforcement 14 , dicalcium alumínate powder as the self-repairing filler 15 , nanoscale boehmite crystal as the wear resistant filler 16 , and crystalline zinc phosphate as the primer 17 . To meet these material criteria, BNL developed smart, high-performance polyphenylenesulfide (PPS)-based composite coating systems consisting of PPS as the matrix, polytetrafluoroethylene (PTFE) as the antioxidant 12 ' 13 , micro-scale carbon fiber as the thermal conductor and reinforcement 14 , dicalcium alumínate powder as the self-repairing filler 15 , nanoscale boehmite crystal as the wear resistant filler 16 , and crystalline zinc phosphate as the primer 17 .…”