Study On Synthesis And Application Of Two-component Polyurethane Adhesives

Polyurethane is a new type of organic polymer materials, and it has beenwidely used in the field of automobile manufacturing, refrigerator manufacturing,civil construction, shoes and so on with its excellent performance. With thesubmission of the energy conservation and emission reduction in the12thfive-year-plan, polyurethane will have a larger development space as it is aenergy saving and environmental friendly material. At2012China petroleum andchemical industry federation issued polyurethane development planning proposalin12th five-year-plan，To the end of2015, it is estimated that polyurethaneindustry scale will reach9million to10million tons, meanwhile speed up theadjustment of industrial structure, improve product level, form the greenenvironmental protection and low carbon efficient polyurethane materialsindustrial system.A series of two-component waterborne modified polyurethane wereprepared. The relationship between the structure and property was studied indetails, and the application technics was also discussed preliminary. The maincontent of this thesis is shown as follows:（1） In this experiment, two component waterborne polyurethane adhesivewere obtained by hydroxyl polyurethane-acrylate（PUA） composite dispersionwith synthesized curing agent. The waterborne curing agent was prepared byreaction of isophorone diisocyanate（IPDI）and polyethylene glycol single methylether （MPEG）. The synthesis process of curing agent were monitored byAttenuated total reflection Fourier transform infrared （ATR-FTIR） spectroscopy,the structure of curing agent was characterized by1H-Nuclear MagneticResonance （1H-NMR）, and initial tack, peel strength, heat aging resistance, shearstrength, creep resistance of all samples with different curing agent contents（0～8wt%） were measured. And rheological measurements was used as a tool for studying the curing behavior of polyurethane emulsion. The influences ofacrylate （PA） content and curing agent on the film properties were investigatedby particle size analysis and transmission electron microscopy（TEM）,respectively. The results showed when the content of PA is15%and the curingagent is8%, the curing agent dispersed well as an incorporated state in thewaterborne polyurethane. The curing time of samples decreased with increasingcuring agent content at the same treating temperature. The water and alcoholswelling decreased with increasing curing agent content, the peel strengthsignificantly increased up to6.7N/mm.（2）A high solid content anionic polyurethane was prepared by toluenediisocyanate（TDI）, polycaprolactone（PCL）, dimethnololpropionic acid（DMPA）and neutralized by triethylamine（TEA）. Then the aqueous polyurethane reactedwith Dispercoll.U54as outside emulsifier. The particle size distribution of thepolyurethane was researched, the water resistance, mechanical properties,thermal stability and crystallinity of the film were also tested. When w（curingagent）=4.0%, tensile strength is up to30.3MPa, water absorption rate andethanol absorption rate decreased to17.2%and10.9%, contact of angleincreased to69.6°, T_maxis301.5℃, crystallinity decreased from3.77%to1.10%.