Application Of A New Redox System In Free Radical Aqueous Solution Polymerization

Free radical polymerization is one of the most important methods for synthesis of polymers.The polymers prepared by free radical polymerization account for more than 60%of the total yield of the synthetic polymers.The activation energy of oxidation-reduction system is lower about 40-60 kJ/mol than that of general thermal decomposition initiator,so that the polymerization temperature of oxidation-reduction system is lower,hence the reaction can be carried out at or below room temperature.Acrylic polymers are a class of important water-soluble polymer compounds.Polyacrylic acid polymers,binary polymers and ternary polymers and their salts have been widely used.The use of polyacrylic acid polymers is closely related to the molecular weight.Based on this,this paper presents a new redox system for the free radical polymerization in aqueous solutions.N,N-diethylhydroxylamine(DEHA)and APS can form a new redox system in which acrylic acid,methyl acrylate and maleic anhydride could have self-polymerization and homopolymerization in aqueous solution,which has many advantages such as the simple raw materials and low toxicity and molecular weight of the polymers can be controled by changing process conditions.Using ammonium APS and DEHA,a new redox system for the preparation of acrylic acid homopolymers and copolymers controlling the molecular weight distribution,which can solve the defects that the solvent is hard to recycled,dodecyl alcohol system has toxic and irritating odor,the sodium sulfite system release sulfur dioxide,sodium hypophosphite system can contaminate water.This project can be further extended to free radical polymerization of other monomers.(1)The molecular weight distribution of the products are between 13.4K-24.6K,as Acrylic acid was raw material in the redox system which was composed of DEHA and APS.(2)Acrylic acid,methyl acrylate,maleic anhydride as materials,PAA-MA-MAA was prepared through free radical polymerization in the redox system which was composed of DEHA and APS,whose molecular weight distribution are between 9.4K-21.4K.In the process of synthesizing acrylic acid homopolymers and copolymers,this paper mainly investigates the effects on the molecular weight and its distribution of DEHA content,ratio of ingredients,reaction temperature and initiator dosage,and then optimize the technological conditions.The structure were characterized by IR.The molecular weight and molecular weight distribution were measured by GPC.The two kinds of synthetic high carbon esters of polyacrylates were used to reduce the viscosity of heavy oil,and the viscosity reduction effect of heavy oil was measured.