The influence of particle morphology on the structure and mechanical properties of films cast from hybrid latexes

摘要

Two phase latex particles offer a potential route to obtain homogeneous, transparent and mechanically strong films with low minimum film formation temperature (MFFT) without the addition of any kind of volatile organic compound (VOC). In this work, we have studied how the morphology of hybrid latex particles influences the morphology and the mechanical strength of polymer films cast from latex dispersions. Hybrid particles containing a hard, high T-g seed (Styrene(S)/Acrylamide(AM), T-g = 101 degrees C) and a low T-g (Methyl Methacrylate (MMA)/Butyl Acrylate(BA)/Styrene(S), T-g = 13 degrees C) second phase polymer were synthesized. Different particle morphologies were obtained by slight variation of the amount of AM in the seed and S in the second-stage polymer. Film morphologies and properties for films cast at 60 degrees C were compared in order to find a link between particle morphology and film properties. Moreover, the effect of annealing temperature on film morphology was investigated. Through careful control of particle microstructure during the latex synthesis it is shown that good control over the final properties of the polymer film can be obtained, even for nominally similar polymer mixtures.