| 초록 |
Urethane resin has high reactivity and low temperature impact resistance, and improves impact resistance in wide field. Especially, urethane resin in automobile structural adhesives, which is required to have high impact resistance, is a core material having a low Tg of –40°C or less. In this study, urethane oligomer was polymerized with polydiol, isocyanate, and triol as monomers and stabilized with a capping agent such as bisphenol A and Diallylbisphenol A. The reaction and dissociation of capping agent, which effect to viscoelasticity and adhesive performance, are carried out at the curing temperature of the epoxy structural adhesive, and it was confirmed by FT-IR NCO peak of 2270 cm-1 field. The viscosity, molecular weight, molecular weight distribution, and glass transition temperature of the polymerized urethane oligomer were 10,000 to 140,000 cps(Vis. at 40 °C), 5,000 to 8,000(Mn), 9,000 to 12,000(Mw), and –36°C(Tg) by using Brookfield viscometer, GPC, and DSC.
|
