Preparation And Performance Of Waterborne Polyurethane-acrylate With Core-shell Structure Through Radiation-induced Emulsion Polymerization

Polyurethane(PU) has the advantages of high strength，wear resistance，low temperatureflexibility，so it has been widely utilized in dyeing and finishing，synthetic leather，laminated adhesive and other fields. But weather resistance and the price of raw materialsgreatly restricted the development of WPU，people pay more attention to modifiedWPU．The modification of waterborne polyurethane-acrylate is known as “the thirdgeneration WPU”and has made significant research progress．Then radiation emulsionpolymerization as new technology has been used widely in the preparation of lowtemperature adhesive．So preparation of PUA composite latex through radiation-induceemulsion polymerization，make the latex with excellent features of PU and PA．In this paper， firstly， double bounds terminated polyurethane prepolymer wassynthesized using isophorone diisocyanate(IPDI)， polyoxypropylene glycol(N-220，N-240)，castor oil (C.O)，dimethytolpropionic acid (DMPA) as main raw materials，2-hydroxypropyl methacrylate (HPMA) for sealing the agent，triethylamine (TEA) forneutralizer． The research indicated that， when prepolymerization temperature wascontrolled at80-85℃，the content of C.O and HPMA all reached6%，two-step methodby adding DMPA dosage for7%， PU pre-polymer has better properties ofemulsifying and dispersion．Then the obtained prepolymer was mixed with MMA and BA(BA/MMA was5/1) todecrease its viscosity．And PUA could be obtained through mechanical emulsification，neutralization and copolymerization with MMA and BA by Co60radiation(initiator)，respectively．The results showed that，compared with chemical emulsion polymerization，radiation emulsion polymerization has advantages of short reaction time and high monomerconversion rate．Lastly，casting film of PUA was characterized by FTIR，TGA，mechanical propertiesand water resistance test．The results showed that properties of PUA prepared throughradiation emulsion polymerization were superior to that prepared with initiator ofpolymerization．Compared with chemical method，the average particle size was decreasedfrom143.5nm to100nm；solid content was increased from37.5%to38.6%；tensile strengthwas increased from15.3MPa to18.3MPa；water absorption rate of casting film wasdecreased from7.4wt%to5.6wt%；and initial thermal decomposition was increased from320℃to380℃．The PUA hybrid emulsion was used in textile coating printing，the practical application of the results show that it improved dry and wet rubbing fastness andwash fastness．...