Preparation of Water‐ and Alkali‐Resistant Silicone‐Modified Polyacrylate Emulsions and Their Performance Enhancement in Glass Fiber Fabric

ABSTRACT

Glass fiber fabrics used in exterior wall insulation systems are susceptible to alkaline corrosion and mechanical degradation in the highly alkaline environment of cement mortar. In this study, a vinyltrimethoxysilane (VTMS)‐modified polyacrylate emulsion was synthesized via seeded emulsion polymerization. Single‐factor and orthogonal experiments were used to screen the formulation, and a VTMS loading of 7 wt% was identified as a favorable dosage within the tested range. FT‐IR, ¹ H NMR, XPS, and SEM showed that VTMS was covalently grafted to the polyacrylate backbone and that Si–O–C and Si–O–Si groups were present. The emulsion showed a narrow particle size distribution and favorable colloidal stability, and the cured film had a water absorption of approximately 4.0%. When applied to glass fiber fabrics of three basis weights, mean alkali resistance retention values above 75% were achieved at coating add‐ons of approximately 8 wt% for the 113 g/m ² fabric and 10 wt% for the 130 and 140 g/m ² fabrics, satisfying the requirement specified in JC/T 841‐2024. For the 140 g/m ² fabric, the mean retention remained above 78% after separate pretreatment at 80°C and −20°C for 10 h each. This work provides a viable strategy for improving the alkali durability of glass fiber fabrics at low coating add‐ons.