Study On The Properties Of Waterborne Polyurethane Systems And Their Application

In this research, the aliphatic waterborne polyurethane were prepared from isophorone dissocyanate(IPDI), polyester and polyether polyol. It consists of two main parts:(1) the study on cationic waterborne polyurethane;(2) the study on anionic waterborne polyurethane.Cationic and heparinized waterborne polyurethanes were synthesized using N-methyldiethanol amine as the chain-extender. The effects of solid content on viscosity and particle size of emulsion were studied in the first time. The higher the solid content, the bigger the particle diameter and the lower viscosity of emulsion. The effects of the amount of MDEA and the ration of NCO/OH on the particle size, the viscosity of the emulsion, the water-resistance, the tensile strength and the adhesive strength of the ACPU were discussed. It was found that with the increase of the MDEA content, the viscosity of the emulsion and the adhesive strength increased, the particle size decreased, the tensile strength increased;with the increase of the NCO/OH ratio, the viscosity decreased, the particle size and the adhesive strength increased, the tensile strength increased. In addition, we also analyzed the rheology properties of the emulsion with different MDEA content and NCO/OH ratio. The structure of cationic waterborne polyurethane and the structure changes of polymer after heparinization were characterized with infrared spectroscopy. It was showed that the heparinized PU was of excellent antithromboresistance.In anionic waterborne polyurethane system, the effects of the crosslinking agent content on medium-resistance properties of emulsion and mechanical properties of the film were studied. The results indicated the properties of anionic waterborne polyurethane would improved with proper TMP contents. At the same time, the influence factors on microphase separation of waterborne polyurethane were studied by FTIR and DSC, including soft segment type, DMPA and chain-extender contents, different NCO/OH ratio. The results indicated that the microphase separation degree of polyether-type waterborne polyurethanes was higher than polyester-type waterborne polyurethanes. The increase of DMPA amount was related with a lower glass transition temperature, which resulted in higher level microphase separation. The level of microphase separation increased with the increasing of the NCO/OH ratio and chain-extender contents. In the end, we also discussed that the influence factors on adhesive strength of waterbornepolyurethane, including DMPA, TMP and chain-extender contents and different NCO/OH ratio. The results indicated that all the factors increasing the hard-segment contents could benefit to the improving of adhesive strength.*...