Preparation Of The Bio-based Itaconic Acid Series Polyester Rubber Emulsion

In recent years,the depletion of fossil resources is increasing,which strongly impacts on the development of polymer materials.The rich biomass resources have been providing one of crucial ways to develop new polymer materials.In this paper,a series of bio-based unsaturated polyesters were synthesized by bio-based aliphatic dicarboxylic acid,itaconic acid,aliphatic diol.And then the rubber latexes of itaconic acid series polyester were prepared through emulsification process,which had stable and good performance and nano-scale micelle.The bio-based unsaturated polyester rubber latexes can be used for the preparation of bio-based vulcanized rubber particles.A series of bio-based raw materials,including succinic acid,sebacic acid,itaconic acid,1,3-propanediol and 1,4-butanediol were employed to synthesize a series of polyesters.The number average molecular weight of polyesters is in range of 2000-8000,the structure and properties of the bio-based polyesters were investigated by FT-IR,1H-NMR,GPC,DSC,et al.The effects of mole ratio of reactants,degree of vacuum and acid value on the degree of polymerization or molecular weight were discussed in detail.The results show that the desired bio-based unsaturated polyester with homogeneous number-average molecular weight distribution were prepared under conditions of molar ratio for n(diol):n(dicarboxylic acid)= 1.1:1,degree of vacuum at 2000Pa,acid value less than 20 mg KOH/g and the p-toluenesulfonic accounting for 0.05 weight precents of the amounts of monomers,and it is important to the further emulsification process.In addition,the results of DSC show that glass transition temperature of bio-based unsaturated polyester is at-55?,the melting peak temperature above room temperature.Polyester of different structures have different values of HLB because of having various segments in it.Polyester rubber latex with excellent stability and size distribution in nano-scale can be obtained on the condition of 20 ?,strirring speed at 1200r/min for 90 minutes,and then phacoemulsification for 5 minutes.Stability and size distribution of polyester rubber latex were studied from following aspects,including the structure of the polyester,molecular weight and molecular weight distribution,the type and amount of emulsifier et al.The results show that the stability of latex is good and the average particle diameter is about 150nm when the emulsifiers account for 30%of the polyester rubber.The stability of latex will become optimum by using rosin acid potassium,potassium phosphate and A-105 as emulsification system,its micelle particle size distribution is between 50nm to 200nm.In summary,the type and amount of the emulsifier jointly affect the polyester rubber emulsion stability and particle size distribution.