Study Of Composition And Performance Of Complex Inhibitors Of Styrene

It is known that styrene intensely polymerize during the course of purifying, storage and usage, and the polymerization in purifying will induce monomer losing and pipe jamming. Hereby the polymerization were studied systematically and generally at low conversion (0～5%) with different inhibitors.The conversion of styrene was measured by the method of dilatometer. The bulk polymerization of styrene was investigated under mono-composition inhibitors especially 4-hydroxy-2,2,6,6-tetramethyl-piperidingloxy (OH-TEMPO), tri(4-hydroxy-2,2,6,6-tetramethyl-piperidingloxy) phosphite , N,N'-diethyl hydroxylamine, 4,6-Dinitro-2-sec-butylphenol (DNBP), N,N'-diphenyl phenylenediamine and several hindered phenols. From the inhibition characters, there is an obvious induction in the initial polymerization and no retardation after induction, when OH-TEMPO, tri(4-hydroxy-2,2,6,6-tetramethyl-piperidingloxy) phosphite, hydroxylamine are the inhibitors. Whereas DNBP and hindered phenols can bring good retardation without any induction.Combined with the inhibition character of mono-component inhibitor, several multi-component inhibitors were designed. The effects of inhibitor's component type, ratio and concentration were studied. It was found that two-component and three-component inhibitors are more efficient, perhaps because of the cooperation among the components. The three-component inhibitor of OH-TEMPO, N,N'-diethyl hydroxylamine, DNBP has the best inhibition, and the optimum ratio is 6: 5: 5. This three-component inhibitor can give long polymerization induction and retardation.