Study On Synthesis Of Intermolecular Complex Antioxidant

Intermolecular complex antioxidant have two or more antioxiding groups in one molecular for high efficiency, low toxic and low pollution bring into play anti-oxidant function through auto-synergism.Two kinds of new intermolecular complex antioxidants 3-(3, 5-di-butyl-4-hydroxyphenyl) propionyl pentaerythritol phosphate (antioxidant A) and octstearic pentaerythritol tetra- phosphite (antioxidant B) were synthesized by one-pot and two steps transesterification. The effect of catalyst, feeding mode, synthesis method, solvent, temperature, time, amount of catalyst and the molar ration of raw materials on product yield was investigated. The optimal processing technology of antioxidant A and intermediate OPT was determined by orthogonal test. The structure of product was characterized by melting points, elemental analysis, determine phosphorus and IR. The two antioxidants applied to HDPE and PP resin respectively. The effect of thermo-oxidation properties, stabilization in process, tensile properties were evaluated by the tests of OIT, MFR, tensile strength and elongation.The optimum synthesis conditions of antioxidant A were as follows: organic tin 0.3g; xylene 40ml; reaction temperationⅠ115℃, reaction temperationⅡ140℃; reaction timeⅠ1.5h, reaction timeⅡ4h; molar ration of pentaerythritol to triethyl phosphite to MPC 1:1.1:1.10; crystal solvent methanol. The yield of antioxidant A based on 0.05mol pentaerythritol was 93.5%, melting point was 154℃~155.5℃. Antioxidant B was synthesized by two steps, the optimum conditions of intermediate OPT were as follows: based on 0.05mol pentaerythritol, organic tin 0.45g; reaction temperation 130℃; reaction time 3h; molar ration of pentaerythritol to triethyl phosphite 1:4.3. The secondly step was based on 0.01mol intermediate OPT, organic tin 0.3g; reaction temperation 140℃; reaction time 2.5h; molar ration of intermediate OPT to octadecyl alcohol 1:8.3. The total yield of antioxidant B was 65%, melting point was 51.7℃~52.9℃.The testing results (OIT was 4.0min) showed that antioxidant A used in the process of HDPE has antioxidation property. Antioxidant can improvement the fluidity and inhibition degradation of HDPE. The OIT was 2.8min showed that antioxidant B used in the process of PP has good antioxidation property. Antioxidant B can inhibition of oxidative degradation by heating and mechanical shear stress in PP process, but still have certain gap with expectation.