Study On Synthesis And Properties Of Ester-phenolic Antioxidants

Phenolic antioxidants which are used as the main antioxidant have the most excellent properties inthe field of antioxidants. But it develops very slowly. The process of production is so timeworn that thequality of produts is bad and the cost is high. It is important to exploitting new antioxiants with highefficiency and low cost that two kinds of new ester-phenolic antioxidants were synthesized basing on theconventional process ameliorated in this article.The study contains three segments. Firstly, two kinds of new ester-phenolic antioxiants, triethyleneglycol bis[3-(3,5-di-tert-butyl-4-hydroxy-phenyl)]propionate (antioxidant A) and [3-(3,5-di-tert-butyl-4-hydroxy-phenyl)]propionyl phosphoric acid bisoctadecanol ester(antioxidant B), were synthesized byone and two steps transesterification separately. The best catalyst of transesterification was ascertained inexperiments. The influence of temperature, time, amount of catalyst and the molar ration of raw materialson the yield of products were studied. The optimum reaction contidions were ascertained. Then, themolecule structure of products was characterized by testing melting points of products, elementalanalysis, IR. Lastly, the antioxidants were applied to PVC, HDPE5000S, PP separately. The influence ofantioxidants and the amount of antioxidants used on thermo-oxidation proterties, stabilization in process,tensile proterties were evaluated by the tests of torque, OIT, MFR, tensile strength and elongation atbreake. The effects were compared with Irganox1010 and bisphenol A which were the most popularantioxidants in resin.The characterization proves that the products were antioxidant A and antioxidant B.The results showthat the optimum condtions of antoxidant A are as follows: solvent toluene;reaction time 3.5h;reactiontemperation 130℃;catalyst used organic tin and quantity 2.3 wt% of MPC;molar ration of MPC totriethylene glycol 2.1:1;extraction solvent petroleum ethter;recrystal solvent methanol, and the optimumcondtions of antoxidant B are as follows: solvent of the first step toluene;solvent of the second stepdimethylbenzene, reaction timeⅠ2.5h;reaction timeⅡ3.0h;reaction temperatureⅠ145~150℃;reactiontemperatureⅡ175~180℃;molar ration of MPC to diethyl phophite to ctadecanol 1:1.05:2;catalyst usedorganic tin and quantity 1.5 wt% of MPC;purification solvent ethanol.The results of ageing resistance tests show that antioxidant A used in the process of PVC has goodantioxygenation properties, its antioxygenation properties are more excellent than that of bisphenol A,and when the amount of antioxidant A used is 4.5‰, the stability of PVC is best. The antioxygenationproperties of antioxidant A used in HDPE5000S are similar to Irganox 1010. When the amount ofantioxidant A used is 1.5‰, the efficiency of antioxidantion is best. Antioxidant B used in PP has goodeffect of antioxygenation, but its antioxygenation properties are not as excellent as Irganox 1010. Whenthe amount of antioxidant B used is 3.0‰, the efficiency of antioxygenation is most outstanding.