| Unsaturated polyester impregnating varnish is one of theimpregnating varnish. There are lots of advantages in it, such as excellentchemical resistance, moisture resistance, electrical insulation, lowviscosity and mobility etc. Therefore, the unsaturated polyestersolventless impregnating varnish is the main trends in the impregnatingvarnish field. Hyperbranched polyester has some advantages, such as lowviscosity, fluidity, easy modification, molecular weight controlling andhigher temperature of initial decomposition. It was used for paint andsustained release drug etc. In this paper, the preparation of unsaturatedpolyester resin and hyperbranched polyester resin was studied. And therewere used for insulation structure, which consist by solventlessimpregnating varnish, film and mica tape.The unsaturated polyester resin was synthesised by the materials ofEG, BDO, PA, MA etc. Using HEA to block UP, HEA end-blockedunsaturated polyester resin was preparated. Using the methods of iodinevalue and acid value characterization, the process of the resin during thereaction was controlled and the change of the double bonds was analyzed.The influence of catalyst and inhibitor show the optimal dosage ofcatalyst is1.2%, and inhibitor optimum dosage is0.08%. Making use oforthogonal design method for unsaturated polyester resin formulationdesign, the results showed that reasonable formula for the impregnatingvarnish unsaturated polyester resin is EG: BDO: MA：PA: HEA=1.1:1.1:1.25:0.75:0.17. The resin was characterized by FT-IR, GPC, H-NMR,GC-MS structural characterization. Selecting suitable reactive diluentsand other additives, the unsaturated polyester solventless impregnatingvarnish was preparated. Characterization by DSC, TG and test ofconventional performance and mechanical performance show the varnishhas many advantages such as low viscosity, excellent electric properties,low curing shrinkage rate, high bonding strength, good thick layer ofcurable, good storage stability, low volatile etc. The effects of processconditions on impregnating varnish show the best curing temperature of130℃and165℃, curing time is3h each temperature. Using the unsaturated polyester impregnating varnish to the insulation structure,which has excellent electric properties.The hyperbranched polyester resin was synthesised by the materialsof TMP, DMPA, MA etc. Using the method of iodine value and acidvalue characterization, the process of the resin during the reaction wascontrolled and the change of the double bonds was analyzed. Theinfluence of resin synthesis on catalyst and inhibitor show the optimaldosage of catalyst is1.25%and inhibitor optimum dosage is0.1%. Theresin was characterized by FT-IR, GPC, H-NMR, GC-MS structuralcharacterization analysis. Mixing epoxy acrylate resin as modifier, VT asa reactive diluent, the hyperbranched polyester solventless impregnatingvarnish was preparated. Analysis of DSC, TG and test of conventionalperformance, mechanical performance show this impregnating varnishhas the advantages, such as low viscosity, good electric performance,high bonding strength, good thick layer of curable，excellent storagestability, excellent mechanical properties，good storage stability, lowvolatile etc. The effects of process conditions on impregnating varnishshow the best curing temperature is140℃and curing time is4h. Usingthe unsaturated polyester impregnating varnish to the insulation structure,which has excellent electric properties. |
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