Polymerization emulsifier adsorption during

Similar results were obtained by Yeliseyeva ei al. (1973, 1975) when studying the sodium alkylsulfonate emulsifier adsorption kinetics during polymerization of butyl acrylate and its copolymerization with such water-soluble monomers (3 o) as methacrylic acid, JV-melhacrylamide, and JV-methylolmethacrylamide, In all cases the introduction of water-soluble comonomers resulted in a decrease of the effective rate and in the value of the emulsifier adsorption. The authors attributed this to the hydrq>hili-zation and increase of polarity of latex particle surfaces. 

Qnulsion polymerization of lower alkyl acrylates was studied in terms of Interfacial phenomena. Adsorption of emulsifier depending on its nature reduces during... 

Any consideration of the stability of polymer latices would be incomplete without some discussion of the stability of the colloidal polymer particles formed during the course of an emulsion polymerization. As pointed out 1 Dunn and Chong (1 70) the adsorption of the emulsifier plays a major role in determining the surface charge density of the particle and hence in determining the final particle si%. 

The restricted adsorption of anion-active emulsifier during polymerization of polar monomers (vinyl acetate) has also been reported in other work. Breitenbadi eX ul. (1970) established that in the case of polymerization initiated hy a,forming interface. The polymerization rate was found to depend on emulsifier concentration to the power of 0.1. 

Under dynamic conditions of emulsion polymerization the process of formation and aggregation of primary particles is accompanied by estab-Hshment of an equilibrium adsorption of the emulsifier on the polar surface of particles. As a result of competition of these processes, secondary" panicles of complex structure are formed (Figs. 11 and 14). The rate of attainment of equilibrium adsorption, depending on monomer polarity and the nature of the emulsifier, determines the degree of limited flocculation of primary particles at which aggregate stability of the secondaiy" latex particles is reached. The formation of nuclei from micelles during the... 

Random-distribution solution SBR vulcanizates are less hysteretic than are comparable vulcanizates of E-SBR. Also, solution polymers contain less nonrubber material. This is because there is absence of emulsifier (e.g., soap) during polymerization. During coagulation of the polymerized emulsion to obtain the rubber, fatty acids are formed. The presence of such fatty acid, in part, reduces the rate of vulcanization with respect to that of solution SBR compounds. The absence of such nonrubber components also reduces the electrical conductivity of S-SBR compounds compared to those of E-SBR. Vulcanizates of solution SBRs, having blocky monomer distributions, have very low brittleness temperatures due to the presence of relatively long polybutadiene chain segments. They have good elastic properties, low water adsorption, low electrical conductivity, and excellent abrasion resistance. 

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