Tailoring adhesion in paints: synthesis and characterization of poly(vinyl acetate-co-2-ethylhexyl acrylate) copolymers using silane promoters

This work explores the role of silane modifiers vinyl trimethoxy silane (VTMS) and 3-(trimethoxysilyl) propyl methacrylate (3-TMSPMA) in tailoring the structure and performance of vinyl acetate–2-ethylhexyl acrylate (VAc–2EHA) copolymer emulsions. The silanes were incorporated either during polymerization or through post-addition to assess their influence on network formation and film durability. The prepared latexes showed approximately 50 wt.% solid content referred to as nonvolatile monomers (NVM) and remained colloidally stable. Spectroscopic analysis verified the integration of silane functional groups into the polymer chains. Thermal evaluations confirmed that VTMS produced the most thermally stable and well-crosslinked structure, while differential scanning and dynamic mechanical analyses indicated a denser yet flexible polymer network. Surface and stability studies demonstrated that silane addition during polymerization resulted in smaller, smoother and more hydrophobic particles providing superior resistance to water absorption and better film uniformity. By contrast post-added silanes showed limited bonding efficiency and reduced network compactness. The findings highlight that in situ incorporation of VTMS offers the most effective approach for achieving durable water resistant and thermally stable films suitable for high-performance waterborne coatings.