| 摘要 |
Polyurethane foams are made using a biuret-modified MDI and/or PMDI as the isocyanate component. The isocyanate is characterized by having a high content of biuret-containing oligomers and, preferably, a low proportion (if any) of biuret-urea oligomers. Flexible, resilient foams made using this biuret-modified isocyanate perform well on flammability tests such as the UNI 9175 CS. E. RF4 test, even without added flame retardants. |
