Studies On Synthesis Of Antioxidant1076and Antioxidant1010

Octadecyl-β-(4-hydroxy-3,5-di-tert-butyl-phenyl) propionate (antioxidant1076)and pentaerythritol tetrakys [β-(3,5-ditert-butyl-4-hydroxyphenyl) propionate](anti–oxidant1010) are the kind of high performance hindered phenol antioxidant. Theyare single phenolic antioxidants in representative products. Used in plastic which hasmany advantages, such as the compatibility of polymer resin, the higher efficiency ofhinder oxidation. In this paper, synthesis of antioxidant1076and1010were studiedthrough transesterification using methyl3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (MPC), stearyl alcohol and Pentaerythrite as raw materials.Firstly, the synthesis of antioxidant1076was studied. The influences of catalystaddition temperature, catalyst dosage, molar ratio, reaction time and reactiontemperature on product yield were studied. The obtained optimum reaction conditionswere: catalyst addition temperature90℃, n(MPC):n(stearyl alcohol)=1.02:1, reactiontemperature160℃, reaction time5h, catalyst dosage2%(MPC wt%). Refiningprocess of product were studied. the obtained optimum purification conditions were95%ethanol as recrystallization solvent, dosage of recrystallization solvent8mL/g,recrystallization temperature was0~5℃. Under above conditions, the yield and purityof the product were≥85%and100%, respectively.The recycling process of mother liquor of crystallization was studied. Theinfiuences of m(concentrate):m(methanol), temperature and times on product recycledyield were studied. The obtained optimum reaction conditions were:m(concentrate):m(methanol)=7:1, reaction temperature160℃, reaction time6h.Under above conditions, the purity of the MPC, yield of MPC and stearyl alcohol,were≥99%and≥84%, respectively. The structure of product antioxidant1076andobtained MPC were characterized by HPLC and FT-IR.Secondly, the synthesis of antioxidant1010was studied. The influences ofcatalyst addition temperature, molar ratio, reaction temperature, reaction time andcatalyst dosage on product yield were studied. The obtained optimum reactionconditions were: catalyst addition temperature110℃, n(MPC):n(PE)=4.3:1, reactiontemperature190℃, reaction time10h, catalyst dosage3.3%(MPC wt%). Refiningprocess of product were studied. the obtained optimum purification conditions were:95%ethanol as recrystallization solvent, dosage of recrystallization solvent3.5mL/g,recrystallization temperature was0~5℃. Under above conditions, the yield and purity of the product were more than89%and100%, respectively.The recycling process of mother liquor of crystallization was studied. Theinfiuences of m(concentrate):m(methanol), temperature and times on product recycledyield were studied. The obtained optimum reaction conditions were:m(concentrate):m(methanol)=7:1, reaction temperature160℃, reaction time6h.Under above conditions, the purity of the MPC, yield of MPC and PE, were≥99%and≥81%, respectively. The structure of product antioxidant1010and obtained MPCwere characterized by HPLC and FT-IR.