Preparation And Application Of Cationic P(St/BA) Latex With High Solid Content & Large Particle Size

Emulsion asphalt now is applied in the road building largely, not only for it,s low pollution, but for it,s economic energy sources. In order to improve the toughness of the asphalt, strengthen the anti-cold and anti-heat performance, we are apt to choose the rubber as the reagent. In this thesis, I take the soap-free polymerization to synthesize the cationic styrene & butyl acrylate emulsion.In this paper, styrene and butyl acrylate are used as the main monomers, DMC or DADMAC is used as co-monomer, and AIBA is used as the induction to polymerize the cationic emulsion of P(St/BA).The particle size can be controlled from 100 to 500nm by choosing different co-monomer, and using the mixture of both co-monomers. By mixing the P(St/BA) emulsion and asphalt of SK-70 and K-70, we studied the properties of emulsified asphalt and improved asphalt. By comparing the performance of American products and ours, we find out that the emulsion whose particle size is at 300nm has good performance. So we take our hearts to synthesize and study the particles of 300nm in the following experiments.In the paper, we apply the method of DLS, DSC and GPC to studied the performance of American products and our P(St/BA) latex, and researched the molecular weight, temperature of glass, particle size and particle size distribution. Besides of these, we also research the various factors which influencing the particle size of polymers. In the experiments, we get out that the particle size is small with the use of single DMC, and the condition is reverse with the use of single DADMAC, however, by mixing both materials, we finally get what we want.For the high content of solid, we use the mixture of emulsions of small particle size and large particle size as seed, and via seed emulsion polymerization, the content of solid we get could arrive at 55%, and even 60%.From the experiment, I learned the knowledge of soap-free emulsion mechanism and could control the particle size, the most important is that we give the basic data to improve the toughness of asphalt.