Polymer Adhesion to Geopolymer via Silane Coupling Agent Additives


  • Presented in part at the 9th International Meeting of Pacific Rim Ceramic Societies July 12, 2011 (Symposium 17: Geopolymers and Other Inorganic Polymers, 17:20).

Author to whom correspondence should be addressed. email:


Silane coupling agents were successfully incorporated into alkali-activated aluminosilicate geopolymers (GP) through simple mixing into the precursor liquid. This allowed for synthesis of thick coatings with meaningful long-term shear and tensile adhesion to organic polymer substrates. Adhesion of GP to high-impact polystyrene sheets and extruded polystyrene foam was quantitatively evaluated. GP drying shrinkage and coating-substrate thermal expansion mismatch were identified as the major obstacles to adhesion, and these were mitigated by the easy yielding of polystyrene foam. The coupling agent-modified GP experienced decreased splitting strength, but Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy were used to verify that the coupling agent addition did not inhibit geopolymerization.