Application Research Of Antioxidants In PS Resin

Because of the advantages of plastic materials,such as low price,light quality areused in all walks of life. But the serious problems of aging and waste plasticprocessing difficulty, obviously are not in line with the requirements of theenvironmental protection today. How can extend the lifespan of the plastic products,coming into my vision. So consider adding antioxidants in plastic processing andinvestigate the antioxidant efficiency and comprehensive performance of differentantioxidants. The study mainly was divided into three parts.The study discussed extrusion and inject molding processing parameters of PS resinfirstly.Discussing two PS resin processing formula, the product of the first itsmechanical strength is larger but brittle, second strength decreases but good toughnessand easy operation in the processing.The stability of PS resin contained differentproportion antioxidants1010,1010/168during repeated processing were studied bymeans of the determination of the oxidation induction time,yellowness index,thechange of melt mass flow rate.The change of mechanical property after the hot airaging text was also employed.The results showed that hindered phenolic antioxidant1010and phosphite antioxidant168producing good synergistic effect on manyindicators were much better than just adding antioxidant1010system.In168/1010system,dosage of antioxidant1682times the1010,integrated best performance.Whenadding antioxidants more than1%,the PS resin processing stability and mechanicalproperty would be decreased.By use of Friedel-Crafts reaction, the antioxidant2,6-di-tert-butyl-4(dimethylamino methyl) phenol was synthesized with2,6-di-tert-butyl phenol, formaldehydeand dimethylamine as the raw materials.The characterization of the structure of2,6-di-terti-butyl4(dimethyl amino methyl) phenol was done by means of IR and1H-NMR. And the optimal synthesis technology was determined by means oforthogonal experiment:The reaction temperature of the first step was5℃with thereaction time being40min; the reaction temperature in the second step was80℃withthe reaction time of3.5h; molar ratio of2,6-di-tert-butyl phenol to formaldehyde andto dimethylamine were1:1.7,1:2.75respectively. The study discussed the pros and cons of three kinds of compound antioxidants，antioxidants1010/168,antioxidants B215,antioxidants2,6-di-tert-butyl-4(dimethylamino methyl) phenol/168.The results showed that labmade/168compoundantioxidants performance best in the mechanical properties, oxidation induction time,melt index, index of hot air aging, but worst in the yellow index performance. Easy tocontribution color to the material in the processing, so need to color compensation.The optimal group (0.6%) of antioxidant B215is a bit poorer than antioxidants1010/168optimal group in each test.