Properties of Halogensilane Modified Poly(vinyl acetate) Dispersion

Abstract

According to the humidity resistance class corresponding to D3 class of LST EN 204:2004 standard, strength of adhesive joints bonded with poly(vinyl acetate) (PVA) dispersions after 4 days of soaking in water should be not less than 2 N/mm². A considerable higher strength was obtained after modification of the dispersion with special monomers – silica derivatives. Such monomers contain chemically active groups, which after polymerization comprise spatial structures of molecules. Silica derivatives are characterized by high reactivity with compounds containing hydroxylic group, including poly(vinyl acetate). An especially good resistance to humidity was obtained for modified PVA dispersion with silica derivative – halogensilane SFTC. Investigations of the properties of modified dispersion were conducted to determine moisture resistance, duration of initial bond, influence of the dispersion on color change of some wood species widely used in industry, determination of the duration of open and closed exposure until compressing, influence of wood humidity on the strength of adhesive joints. PVA dispersion modified with halogensilane shows better properties than PVA dispersions at present applied in wood industry.