Studies On Modification And Technics Of Waterborne Polyurethane

Aliphatic waterborne polyurethane was synthesized by modified with dihydropolydimethylsiloxane, acrylics, respectively. Identification of middle-testing for the waterborne polyurethane was proceeded on the basis of lab's experiment.DHPDMS-polyurethane which had a solid content of 38% and volatile organic compound (VOC) of 60g/L was prepared with isophorone diisocyanate(IPDI), polyester diol (PCD, PBA), dihydropolydimethylsiloxane(DHPDMS), dimethoxyp- ropionic acid (DMPA). Effects of the amount of DHPDMS, the molecular mass of DHPDMS and glass transition temperature (Tg) on the appearance, viscosity, adhesion, water resistance, hardness, tensile strength, elongation of polyurethane modified by DHPDMS were discussed. The optimal condition was concluded as follows: WPU shows the better performance when the amount of DHPDMS is 2%.Identification of the middle-testing technology for the DHPDMS-PU was proceeded on the basis of our lab's experiment. And the PU resin with a solid content of 38%, high conversion of 96% was successfully prepared. Partial gelation was also successfully solved. The stuff of identification such as new technology bulletin of waterborne polyurethane, bulletin of middle-testing technology, industrial standard, bulletin of quality certification, bulletin of novelty, bulletin of environmental evaluation, verification of users, explanation of achievement. The final result of the identification was international advanced.Waterborne polyurethane/acrylics (PUA) was synthesized by polyester diol, isophorone diisocyanate(IPDI), dihydrooxypolydimethylsiloxane(DHPDMS), hydroxylethyl acrylate(HEA) and so on. Then methyl methacrylate(MMA), butylacrylate (BA) was added to the PUs, the copolymerization was occurred in the presence of initiator(potassium persulfate). The PUA emulsion had a solid content of 36% and performances of the films such as viscosity, hardness, water absorption, tensile strength, elongation were measured. Films were also characterized by FTIR, DSC, SEM. The FTIR spectral result indicated the presence of lots of hydrogen bonds and micro-phase separation. The DSC and SEM results verified the above conclusion.