METHOD FOR PREPARING FROTHING POLYSTYRENE Russian patent published in 2005 - IPC

FIELD: polymers, chemical technology.

SUBSTANCE: invention describes a method for preparing frothing polystyrene by polymerization of styrene for two stages. At the first stage forpolymerization is carried out in the presence of antipyrene, a chain growth regulator, benzoyl peroxide as a polymerization initiating agent. At the second stage the suspension polymerization is carried out in aqueous medium in the presence of polyvinyl alcohol as a stabilizing agent, chain growth regulator, tert.-butylperbenzoate as initiating agent and frothing agent. The forpolymerization stage is carried out in the presence of water and dicumyl peroxide as antipyrene synergist is added additionally, and O,O-tert.-myl-O-(2-hexyl)-monoperoxycarbonate is used a additional initiating agent in the following ratio of components relatively to styrene mass, %: benzoyl peroxide : O,O-tert.-myl-O-(2-hexyl)-monoperoxycarbonate : tert.-butylperbenzoate = (0.24-0.25):(0.04-0.06):(0.04-0.10), respectively. Method provides intensification of the styrene polymerization process, improvement of granulometric composition of preparing polystyrene and reducing specific energy consumptions in manufacturing frothing polymer granules.

EFFECT: improved preparing method.

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