Applications And Preparation Of Acrylic Modified Water Borne Polyurethane

In recent years, with the growing intention of the clean production and envirromental, the demand of decreasing the amount of VOC in the coating is getting more and more urgent. All the above make the rapid development of waterborne polyurethane coating products with water as solvent. To get the waterborne polyurethane coating which has the same property as the solvent type product, the key is the preparation of waterborne polyurethane emulsion.Waterborne polyurethane (PU) were synthesized from a polyester polyol (CMA-1044), toluene diisocyanate (TDI), dimethylolpropionic acid(DMPA), triethylamine (TEA) using the method of methyl acetyl. Effects of a mount of R and carboxyl on the preparation and properties of PU were studied. The effections on the properties of PU were studied by changing the content of R, which is mole ratio of isocyanic acid and hydroxyl group. It indicates that the strength of PUA film and the property of hydrophobic enhance by increasing the content of R. The PU is stable by the increasing the carboxyl group, at the same time the hydrophobic property of PU is decreasing.The article synthesizes the waterborne waterborne polyurethane with HEA, MMA, TDI, TEA. Keeping R as waterborne PU, we study the effect of initiator content on viscosity and percent conversion. The percent conversion of polymer will be max when we add 3‰ initiator. We also study the effect of MMA, DMPA content on the stability , viscosity and hydrophobic property. The hardness and water absorbing capacity of waterborne PUA film is increased with increasing of content of MMA and DMPA. The effect of crosslinking agents on water absorbing capacity and adhesion was discussed. At last we compare the structure of PU, PUA and PU/PUA, it indicated that hydrogen bond exists in water borne polyurethane modified with acrylic resin; Compatblity and degree of mixing in PUA were developed by formation of chemical bond in the chain between PU and PA. Compatibility and degree of mixing between hard segment of PU chain and PA chain...