Effect of Wave Treatment in Polymer Synthesis on the Formation of Properties of Polymer Composites

Abstract

A characteristic property of polymer composites as multicomponent heterogeneous systems is their noticeable sensitivity to external factors. Specific features of the dynamic behavior of polymer composites in their production and processing are revealed under wave treatment [1]. Excitation of nonlinear vibrations in multiphase media, such as paints and varnishes, polymer dispersions, etc., enhances heat and mass transfer and phase and chemical transformations, promotes deagglomeration and dispersion processes, and increases the stability of disperse systems. Enhancement of diffusion processes increases the number of collisions of active molecules, which, along with the decomposition of associates of initial oligomers, increases the conversion of reactants and accelerates the polycondensation of bifunctional compounds based on oligobutadienol and polyoxypropylene glycol [2].In this work, we studied the effect of wave treatment on the formation of properties of polymer composites in polymer synthesis by emulsion polymerization. The objects of wave treatment were aqueous emulsions of the following monomers: (1) butyl acrylate in the presence of the sulfonated oxyethylated alkylphenol C-10 as an emulsifier; (2) butyl acrylate, methylmethacrylate, and methacrylic acid in the presence of C-10; and also (3) styrene and methacrylic acid. Wave treatment (excitation of nonlinear vibrations) was performed according to a published procedure [1,2]. Since the vibrational action (the mechanical factor of the action on the interface) can be compared to the action of surfactants (the physicochemical factor) [3], it was of interest to analyze the joint action of wave treatment and surfactants on the properties of emulsions.In previous experiments [4][5][6][7], addition of a surfactant to an emulsion of styrene and acrylic monomers under nonequilibrium conditions (namely, addition to the phase in which these monomers are least soluble) caused an increase in the dispersity and stability of the emulsion in comparison with a conventional technology for producing emulsions by mixing monomers with surfactant solutions. This stabilization was due to the formation of a microemulsion at the monomerwater interface owing to surfactant diffusion through the interface. Since wave treatment of multiphase media enhances mass transfer, one can expect that intensification of the mechanical action on a disperse system can enhance surfactant mass transfer.The figure presents the results of experiments on breaking up emulsions of butyl acrylate and emulsions of butyl acrylate, methylmethacrylate, and methacrylic acid in a centrifugal force field at 3000 rpm. The emulsions were prepared using stirring with a magnetic stirrer at 300 rpm and using wave treatment. The emulsions obtained by mixing an aqueous solution of C-10 with monomers had low stability and were broken up virtually completely. The acrylic monomer emulsions prepared by introducing the surfactant into the monomer phase remained stable for a longer time and contained a significant amount o...