Synthesis And Characterization Of Blocked Cationic Waterborne Polyurethane

In the current global environmental protection for the voice of growing background,waterborne polyurethane has been more and more studied and applied because of its non-toxic,tasteless,non flammable and non polluting.Among them,terminated cationic waterborne polyurethane because of its molecular chain with positive charge,and can restore the characteristics of deblocking reaction activity at a certain temperature,are widely applied in many fields.This paper mainly uses polyether-1000(PPG),isophorone diisocyanate(IPDI),N-methyl two ethanol amine(MDEA)as the main raw material,using different sealers methyl ethyl ketoxime,imidazole,to prepare waterborne polyurethane,waterborne polyurethane modified by silane coupling agent N-(beta-ammonia-ethyl)-gammaammonia-methyl two-(KH602).Using two n-butyl amine method determination of free-NCO content in reaction system to determine the reaction time,The structure was analyzed by infrared spectroscopy(FT-IR).And by differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA)analysis of deblocking temperature and thermal stability of blocked waterborne polyurethane.Treatment of filter paper using synthetic aqueous polyurethane,the surface morphology changes were observed under the scanning electron microscope(SEM),and its application in the field of paper wet strength was preliminarily explored.The results showed that the meko blocked cationic waterborne polyurethane,Imidazole blocked cationic waterborne polyurethane were successfully prepared,silane modified cationic waterborne polyurethane.When using methyl ethyl ketoxime as blocking agent and the quantity of cement is 10%,the sealing rate was 10%,the wet paper strength reached 48.3%;when using imidazole as blocking agent,the adhesive volume was 10% and the sealing rate was 10%,the wet strength of filter paper reached 45.4%;When using a closed rate of 10% silane modified waterborne polyurethane,The wet strength of filter paper reached 45.4% when the amount of adhesive was 5%.