A Study Of The Modification And Synthesis Of Water-based Polyurethane Dispersoid

In recent years, people pay more and more attention to the impact on the environment and human body in the application of coating and polyurethane paint has been gradually developing from solvent paint into water dispersion paint or water polyurethane in the world. In terms of raw material, water-based polyurethane can be divided into three categories, including aromatic, aliphatic and cyclic aliphatic ones.Types, performance, quantity and quality of water-based polyurethanes developed and produced in China still lag far behind international levels. The coating layer of domestic products has such defects as high moisture absorption, low water resistance and low wet friction resistance. The article studies the possibility to improve water resistance and hardness by modifying water-based polyurethane with epoxy resin.Aromatic water-based polyurethane is most commonly used at home and it tends to yellow during its process of storage and application. The article synthesizes water-based polyurethane with aliphatic IPD1 and polyester polyols or DMPA through crosslinking, and it also discusses the influences of reaction temperature, NCO/OH, dosage of crosslinking agent, catalyst, neutralizer and pHto the performance of emulsion and coating film. It studies the influences of the way and the amount of DMPA addition and has found solution addition to be the best way and 7% 8% the best amount. It also makes a comparison on the influence of BDO/DEG, a small molecule chain extender, and studies the modification to water-based polyurethane by the addition of epoxy resin and caster oil and tests the product with Infrared Spectrometry.Due to the low price of polyether-TDI-acetone system, most of water-based polyurethane emulsion made in China on domestic market applies aromatic isocyanate monomer. It synthesizes water-based polyurethane with aromatic TDI and polyether polyols or DMPA through cross-linking and discusses the influence of reaction temperature, NCO/OH and other factors to the performance of emulsion and coating film. It studies the influence of the amount of epoxy addition and has found 6% 8% to be appropriate, and it also studies the influence of the amount and the way of DMPA addition and has found 7% 8% to be the best amount and solution addition to be the best way. Furthermore, it studies the influences of TMP content, of the type of soft-segment and its content, of the content of chain extender EDA and of the catalyst and makes Infrared Spectrometry analysis on products with or without epoxy resin.