Preparation And Characterization Of Sulfonated Waterborne Polyurethane Adhesive With High Solid Content

Compared with the carboxylic acid type waterborne polyurethane adhesive,sulfonated one possesses many outstanding features, such as high solid content and high bond strength, which had quickly became a research hot spot in recent years. This thesis is focused on the preparation and application of it in cars. The results are shown as following.One is the preparation of sulfonated waterborne polyurethane(SWPU) adhesive.SWPU with 50% solid content was prepared using poly-1,4-butylene adipate glycol,isophorone diisocyanate, small molecule chain extender as the main raw materials, and2-[(2-aminoethyl)amino]-ethanesulfonic acid monosodium salt(AAS) as the hydrophilic reagent. We explored the effects of AAS content, the kinds of small molecule chain extender, and the value of NCO/OH(R value) on the water absorption, emulsion appearance, mechanical properties, and heat resistance. When the content of AAS was about 2.2%, the chain extender was 1,6-hexanediol, and R value was 1.8, the water absorption of the SWPU film was 7.4%, the tensile strength was 20.3 MPa, and the elongation at break was 510%. The peeling strength test showed that the substrates of polyurethane foam and sponge were completely destroyed, which proved that it had an excellent bonding performance.The other is the modification of SWPU adhesive. When it was doped with carbonaceous nanotubes at a content of 0.2 wt%, the thermal decomposition temperature T5% increased 2.5oC and the water absorption decreased to 4.8%. Moreover, for the carbon/silica nanotube doped SWPU, the thermal decomposition temperature T5%increased 7.9oC and the water absorption decreased to 3.5%.