Synthesis And Application Of New Hindered Phenolic Antioxidant

Antioxidants can effectively reduce the rate of auto-oxidation reactions in materials,and thus it has become an important auxiliary agent to delay the agi ng and degradation of materials.Its applications involve almost all polymer pro ducts.In this paper,a new type of bisphenol monoacrylate antioxidant 2-prope noic acid,2-(1,1-dimethylethyl)-6-[[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]methyl]-4-methylphenylester(antioxidant 3052)was developed.It has two active groups of phenolic hydroxyl group and acrylate group,so it could effectively prevent the thermal aging of the polymer.The protection effect is more promin ent when the product is under high temperature and anaerobic conditions.In th is paper,the target product is synthesized by one-pot method and two-step met hod,in addition the process conditions are optimized respectively,in order to d iscuss its industrial application.The optimization results are(1)Acrylic acid chloride and solid phosgene are used as raw materials,and N-N dimethylformamide is used as a catalyst to synthesize the intermediate acryloyl chloride.An optimized process was also carried out.The optimal condition was n(acrylic acid): n(BTC)was 1: 0.35,the reaction temperature was 45 ?,the optimal reaction time was 4h,and the amount of catalyst NN dimethylformamide accounted for 1.8% of the quality of solid phosgene.Under this optimal condition,the yield of acryloyl chloride is above 72%,and the purity reaches 98%.(2)The target product antioxidant 3052 is synthesized with bisphenol A2246,acryloyl chloride as the raw material,methylene chloride as the solvent,and triethylamine as the catalyst,and an optimized process was carried out as well.The optimal conditions were n(bisphenol A2246): n(acryloyl chloride)was 1: 1.1,reaction time was 2h,and reaction temperature was 40 ?.Under this condition,the yield of the synthetic antioxidant 3052 was above 83%,and the purity reached 98%.(3)Using multi-component one-pot method,solid phosgene was used as green acid chlorination reagent,using bisphenol A2246 and acrylic acid as raw material,and antioxidant 3052 was synthesized by dropping acid chlorination reagent.The effects of curing temperature,material molar ratio,feeding method and curing time on the target product antioxidant 3052 were investigated through orthogonal experiments.The optimized process conditions were established as follows: the reaction curing temperature was 40 ?,the material ratio was 1: 1.30,the dropping method was semi-alternating,and the curing time was 60 min.Pilot scale-up experiment of optimized process conditions was carried out,and the results showed that the yield of the target product could reach 83.5% and the purity reached 98%.The application evaluation of the target product in the production of ABS resin shows that it can significantly improve the yellowing resistance of the product.Establish gas chromatography and liquid chromatography analysis methods to test the purity of the product,and characterize the target product by nuclear magnetic,infrared and determination of melting point.