| 摘要 |
<p>A novel microporous isocyanate-based xerogel composition is disclosed. The composition can be prepared by a method comprising (1) (1) admixing (a) a polyisocyanate component, (b) a substantially unreactive solvent, and, optionally, (c) a polymerization catalyst, water, an active-hydrogen compound or a mixture thereof, provided that (c) is included wherein (b) does not also function to catalyze polymerization; under reaction conditions sufficient to form a gel; and (2) removing the solvent under non-supercritical conditions sufficient to form a microporous xerogel composition. The compositions can be readily evacuated for use in thermal insulative applications such as vacuum panels, for uses such as appliance insulation, which show superior K-factor values when compared with, for example, conventional rigid polyurethane open-cell foams as used in similar applications.</p> |
