The anionic waterborne polyurethane was synthesized by the reaction of toluene di-isocyanate(TDI) with polyester glycol and dimethlolpropionic acid(DMPA) with the process ofprepolymerization step by step and self-emulsification.Studied the factors which influence the re-action.The results show that the performances of emulsion is optimum when NCO/OH ratio is 1.5~2.3 and the amount of DMPA is 3%~8%.

Nanosilica particle containing flexible interval polyethylene glycol and epoxy nanosilica composite were prepared by modifying nanosilica particle surface with polyethylene glycol.The structures of the products were characterized by IR and the mechanical properties were tested.It is found that that nanosilica can be effectively capsuled by polyethylene glycol.As a result,the flexible interval is successfully introduced onto the surface of nanosilica particles,and the stickiness between the epoxy and nanosilica as well as the material toughness are remarkably improved.

The anionic waterborne polyurethane was synthesized by the reaction of toluene diisocyanate(TDI) with polyester glycol and dimethylolpropionic acid(DMPA) with the process of prepolymerization step by step and self-emulsification.And the results showed that the DMPA dosage,material-introduct mode(adding in powder or dissolved state),reaction time,reaction temperature,selection of emulsion technology were main influential factors on emulsion and cast films performance.