THE INFLUENCE OF POLYSILOXANE DICABOXYLIC ACID ON STYRENE BUTADIENE LATEX PROPERTIES

Abstract

The aim of this work is researching of influence of polysiloxane dicarboxylic acid (PSDA) on properties of styrene butadiene latex (SBL) and films based on it. PSDA is industry manufactured organic silicone water insoluble surfactant able to form stable oil-in-water emulsion in a presence of 0.1 weight parts. Synthesis of SBLs with different ratio of the emulsifiers Disponil FES 32 and PSDA was carried out by free radical emulsion polymerization with potassium persulfate initiator. Solid contents of SBLs is slightly depended of the emulsifier content mixture. Surface tension of modified SBLs is negligible higher in comparison to classical SBL. It was found via dynamic light scattering that size of the latex particles is decreased in a presence of 3.0 weight parts of Disponil FES 32 and 0.5-1.0 weight parts of PSDA, and growth of the latter content leads to particle size increasing. Mechanical stability evaluated as coagulum formation, and foam formation ability of SBLs also improved in a presence of 0.5-1.0 weight parts of PSDA. Latex films obtained from the modified by PSDA SBLs possess better mechanical properties. It should be noted that water sorption properties of modified latex films (Fig.1) are dramatically declined for SBLs prepared with PSDA use due to high hydrophobicity of organic silicone compounds. To sum up, presence of 0.5-1.0 weight parts of PSDA in initial polymerization emulsion leads to improving of some  properties of SBL and films based on it such as mechanical stability, foam formation ability of latexes and water sorption ability of modified SBL films.