Synthesis Of Waterborne Polyurethane Resin

In this paper, Waterborne polyurethane resin were synthesized by use of IPDI, POG(H1000.H2000), polyester polybasic alcohol(3162.3196),propylene glycol(PG), triethylamine(TEA), ethylene diamine(EA), dimethylol propionicaid(DMPA), N-methyl pyrrolidone(NMP). The influence of synthesis way, raw material type, EA contents, NNCO/NOH, DMPA content on the appearance, storage stability, membrane mechanic properties and water resistance of the waterborne polyurethane resins were studied. By use of NMP, well-controlled reaction temperature, agitation speed and conditioning, a storage stability and low water absorption, high tensile strength, high elongation at break waterborne polyurethane resin can be obtained. A simple, effective and practical stable production process is realized. Using FT-IR, XRD, to carry on the analysis to the structure of waterborne polyurethane resin, using LPSA to inquiry the influence of DMPA content on particle size and its distribution of polyurethane.The result indicated that synthesis polyurethane raw material must be vacuum treated to depress water content, more water content would emulsion the C02 gas to cause the foaming phenomenon. Under the same molecular weight, polyester waterborne polyurethane resin had strong solidity, low water absorption, low tensile strength, low elongation at break, when it was compared with polyether waterborne polyurethane resin. When EA/PG =0.37, the water absorption is 16.6%, while stability of waterborne polyurethane resin is good. When NH1000 /NH2000 =1.5, solidity of waterborne polyurethane resin is 3H, tensile strength of waterborne polyurethane resin is 10.47 MPa, elongation at break of waterborne polyurethane resin is 6.64%. When NDMPA=0.0225 mol, stability of waterborne polyurethane resin is good, tensile strength of waterborne polyurethane resin is 15.12 MPa, elongation at break of waterborne polyurethane resin is 6.32%.water absorption of waterborne polyurethane resin is 18.34%.Infrared spectroscopy analysis confirmed that, in the polyether polyurethane carbaminate-NH forms the hydrogen bond, emulsion-NCO responded completely. XRD analysis show that: whether change the EA/PG content or not, the diffraction peak distinguishes not obviously. LPSA analysis show that: DMPA content has influence waterborne polyurethane resin on its particle size and distribution. When NDMPA=0.0225 mol, the size of waterborne polyurethane resin is 37 nm, when NDMPA=0.0125 mol, the size of waterborne polyurethane resin is 57 nm.Thermodynamics analysis of polyurethane show that: the solidity of polyether polyols synthesis polyurethane has depress when polyether polyols molecular weight, its thermal deformation temperature becomes lower and the stability of waterborne polyurethane resin becomes worse.