Preparation and evaluation of adhesion and wettability properties of acetate-acrylate-siloxane adhesive

Three-component water-based adhesive composed of acetate-, acrylate- and siloxane-based polymers was investigated, and its various properties were measured in conditions with and without crosslinker. Herein, the hydroxyl-terminated polydimethylsiloxane was converted to acrylated polydimethylsiloxane during a process and fully identified by Fourier transform infrared analysis. Then, it was subjected to miniemulsion polymerization with butyl acrylate in different ratios of 20/80 and 40/60 with and without 1,4-butanediol dimethacrylate (1,4-BDDMA) crosslinker. Finally, tricomponent core-shell particles were formed by granular emulsion polymerization of vinyl acetate. Size, size distribution and morphology of nanoparticles were evaluated by dynamic light scattering and scanning electron microscopy analyses. The wettability results show the increase in the hydrophobicity of the film surface with the increase in the polydimethylsiloxane (PDMS) amount in the copolymer structure. On the other hand, a noticeable crosslink effect in the polymer chains was seen in its water contact angle, in such a way that the particles core crosslinking caused an increase in the formed film hydrophilicity (106-93 degrees). Adhesion analysis including lap shear and pull-off showed a decrease in the latexes adhesion with an increase in the amount of PDMS in their structure. Also, the significant effect of particles crosslinking in increasing the sample mechanical and adhesion properties was evident. Thermogravimetric analysis and thermal analysis showed that the produced copolymers had two transition temperatures in 250 degrees C and 500 degrees C, which are related to the hydrocarbon and siloxane parts of samples, respectively. This analysis also reported an increase in the thermal degradation temperature of X-P(VA/BA-ASM40) by crosslink addition to the polymer chain.