Latex stability failure

The failure of latex stability,and the resultant flocculation of the latex par tides, may cause the formation of coagulum that is recovered from the latex after polymerization as well as a buildup on the reactor surfaces. Moreover, the inherent instability of the latex may also cause flocculation during storage or transportation. 

The formation of coagulum can often be correlated with (i) conversion (ii) agitation rate (iii) mode of addition of ingredients. Generally, the amount of coagulum formed increases with increasing conversion, but this observation may be the result of an initial stability failure which becomes more obvious as the polymerization proceeds. Since latexes can be flocculated by mechani-... 

Coagulum is formed in many emulsion polymerizations, from the smallest laboratory size to the largest production reactors. It is observed in many forms, from a single lump of polymer with little or no fluid latex to tiny sand-like grains suspended in an otherwise stable latex. Usually, it is found as lumps in the latex or deposited on the reactor surfaces. The type and amount of coagulum formed depends upon the polymer system and the polymerization recipe and technique. Two mechanisms are proposed for the formation of coagulum (i) a failure of the stability of the latex, giving rise... 

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