Polypropylene and hollow glass microspheres compatibilization via addition of compatibilizing agents

Abstract The glass syntactic polypropylene composite highlights as the most used wet thermal insulation solution for subsea pipelines. The continuous and disperse phases of the material, however, show low interaction levels due to poor chemical compatibility between the polypropylene matrix and the hollow glass microspheres, ultimately leading to a premature failure when subjected to mechanical loads. This article assesses the use of poly(propylene‐g‐maleic anhydride) and ethylene‐acrylic ester‐glycidyl methacrylate terpolymer as compatibilizing agents to enhance the matrix–filler interaction. The effectiveness of the selected strategy is analyzed through mechanical stress–strain tests, evaluation of absorbed water during hot water immersion, and evaluation of thermal properties. The composites with polypropylene and heterophasic polypropylene matrices, 25% by the weight of hollow glass microspheres, and contents of compatibilizing agents spanning from 1% to 5% by weight were prepared and tested. The addition of compatibilizers increased the tensile strength by 9%–30% and reduced the elongation at break by 13% to 45%. Thermal analyses indicated no significant influence of compatibilizers on melting points and crystallization temperatures; meanwhile, water absorption studies indicated opposite effects of each compatibilizer on the absorbed water content. Finally, the main results observed were ratified through scanning electron microscopy.