The Morphology Of The Particle And Performance Of Organosilicon-acrylate Core-sheell Latex

The performances of polymers formed by the core-shell emulsion polymerization strongly depended on the morphology of the latex particles,different morphologies of latexes can perform different functions, and so the understanding and controlling of the mechanismand development of the morphology of composite latex are beneficial for the industry application. In this paper, there are three aspects about composite latex of siloxane/acrylate core-shell were studied.The morphology of latex particles are predicted by the thermodynamic and the cluster dynamic method, and the infrared spectroscopy,TEM are used to characterize the polymer structure and the morphology of the particles,the results show that the key technique to prepare core/shell is to reduce the interfacial tension between polysiloxane based core and polyacrylate shell; the essential effects of morphology of the latex particles include monomer of siloxane,emulsifier concentration,initiator,cross-linking agent etc; the reaction mechanism of siloxane/acrylate core-shell composite latex is a grafting reaction mecheanism or latex interpenetrating polymer network. Basic of reaction mechanism of siloxane/acrylate core-shell composite latex ,the concept of supramolecule chemistry was used to discussion the core-shell emulsion polymerization, and experiment and analyse of instrument shows that the concept of supramolecule chemistry was advantage for guiding synthesis of siloxane/acrylate core-shell composite latex.The polysiloxane/polyacrylates composite latex with core-shell structure was prepared in the presence of polysiloxane latex as seed, and the infrared spectroscopy,TEM are used to characterize the polymer structure and the morphology of the latex particles .The effects of the morphology and performance of the latex particles were determined: the octamethylcyclotetrasiloxane (D4) in cross-linking agent (NQ-71) is better choice;the amount of core monomer 20%;the amonunt of cross-linking agent (NQ-71)7% ;the amonunt of initiator (KPS) 0.7% by one-time feeding method; the amonunt of emulsifier 4%; the feeding method of shell monomer was continuous;the amonunt of AA 0.6%.The differential scanning calorimetry(DSC),X-ray photoelectron spectroscopy(XPS) are used to characterize the polymer films, the result shows that migration of the internal PS domains in-between the polyacrylic, it is the chief reason that organosilicon-acrylate core-sheell latex with champion performance of polyacrylic and polysiloxane, as the same time, the result shows that migration of the internal PS domains in-between the polyacrylic, core-shell structure were accelerated and stability of particles were enhanced.