Preparation Of Ethanol-soluble Polyurethaneurea Resin And Study On Its Structure And Property

In this paper, polyproplene glycol PPG2000,isophorone diisocyanate or toluene diisocyanate and isophorone diamine were used as the raw material to synthesize ethanol-soluble polyurethaneurea as base material.Part or all of PPG2000 were replaced by PPG600, PEG200, PPG1000, D2000 and PNA2000 or the amount of diisocynate was increased to synthesize a series of polyurethaneurea resin solution in the mixed solvent.The structure and property of resin were stuied by DSC,FTIR,TG and tensile testing.l.When PPG600 was used to replace part of PPG2000, the amount of ordered hydrogen bonded urethane carbonyl groups increased, the degree of hydrogen bonding for urea carbonyl groups decreased with the increase of PPG600 content.There is a better compatibility of soft segment and hard segment.The tensile strength of polyurethaneurea resin was enhanced,elongation at break was decreased. When PEG200 was used to replace part of PPG2000, the amount of ordered hydrogen bonded urethane carbonyl groups increased either,but the degree of hydrogen bonding for urea carbonyl groups decreased first and then increased with the increase of PEG200 content. The tensile strength of polyurethaneurea resin was enhanced more than that of resin with PPG600 which had the same hard segment when PEG200 content was high. The degree of hydrogen bonding for both urethane carbonyl groups and urea carbonyl groups increased when the amount of diisocynate was increased.The micro-phase separation degree of resin increased. The tensile strength of resin was enhanced but less than that of resin with PPG600 or PEG200 which had the same hard segment content.2.The resin prepared by PPG1000 had poor solubility and low molecular weight because of great hard segment density.So it had very poor tensile strength.The resin made by D2000 had very poor mechanical property. Because the strong polarity of more urea groups decreased the chain-extending,which decreased the molecular weight of resin.But the thermal resistance of resin enhanced when urea content was increased.The tensile strength of resin was enhanced when part or all of PPG2000 was replaced by PNA2000.3.Compared to the polyurethaneurea resin based on TDI,the resin based on IPDI had more ordered structure.The hard segments were easy to congregate. So the degree of hydrogen bonding for both urethane carbonyl groups and urea carbonylgroups was higher.4.The resin made by pure polyether diol had better solubility in ethanol. The polyurethaneurea which had polyester in the structure can dissolved in the mixed solvent of ethanol and ethyl acetate.