Research Of Modified Asphalt Emulsion

Using asphalt and distilled water as raw materials,SDS and span-60 as the emulsifier,soluble starch as the stabilizer,high stabilized anion emulsified asphalt was prepared by using colloid mill as the emulsifying equipment.The best reaction conditions were:the dosage of m(soluble starch)=1.5%,m(emulsifier)=2.0%;the temperature of soap liquid was 55 C,asphalt was 125-135 C;the pH value was 11-12,HLB value was 16-18;the emulsified time was 1.5-2min.The properties of the emulsion were as follows:the viscosity was no more than 100mpa·s,the storage stability was no more than 0.5%and the product has good mechanical stability,which could keep uniform and stable for more than 6 months.But the waterproof performance of the product was not very good and the asphalt after breaking from the emulsion was easy to crack,so it need to be modified.Using C18-alkene and vinyl acetate as raw materials,AIBN as the initiator,asphalt modifier was synthesized by the method of bulk polymerization.The best reaction conditions were:m(C18-alkene):m(VA)=1:1,m(AIBN)=1%,the reaction temperature was 80-820C,the reaction time after all vinyl acetate was dropped in was 2h.The properties of the product were as follows:the soften point was 71 C or so,the yield was 75%,the needle penetration was 4(1/10mm)and the average molecular weight was 71559.In order to enhance the sticky and toughness of the product,C18-alkene was replaced by silicone modified alkene,paraffin was used as the flow modifier,caprolactam was used for toughening agent,the asphalt modifier was synthesized by the method of bulk polymerization.The best reaction conditions were:m(silicon modified alkene):m(vinyl acetate)=1:3.0,m(AIBN)=1%,m(caprolactam)=5%m(paraffin)=10%;the reaction temperature was 80℃,the reaction time after all the vinyl acetate was dropped in was 1.5h.The properties of the product were as follows:the drop melting point was 50.5℃,the softening point was 51.5℃,the needle penetration was 30(1/10mm),the product has good viscosity when it was heated and the toughness was also excellent at the room temperature and the average molecular weight of the product was 17892.It could be used as modifier for asphalt to enhance the performance of asphalt emulsion.Using C20-alkene and vinyl acetate as raw materials,APS as initiator,11#,SDS and span-60 as emulsifier,high stabilized and good performance of waterproof emulsion was synthesized by emulsion polymerization.The waterproof performance of asphalt emulsion was greatly enhanced after this emulsion was added.The best reaction conditions were:m(C20-alkene):m(vinyl acetate)=1:2,m(solute):m(water)=1:1.70;m(emulsifier)=20%,m(APS)=1%,m(11#):m(span-60):m(APS)=12:6:2;the reaction temperature was 80℃,the reaction time after all the vinyl acetate was dropped in was 1.5h.The properties of the product were as follows:the solid content was 35%,viscosity was 2mpa·s and the product,which could stay stable and uniform for more than 6 months has excellent waterproof performance.It also has good solubility with asphalt emulsion.