| 摘要 |
{PG,1 Cellular resin bodies having apparent density less than about 30 pounds per cubic foot, where the resin has highly crosslinked three-dimensional ethylenic polymer structure having amic acid groups and/or cyclic imide linkages, are made by reaction of polyisocyanates with certain polymerizable ethylenically unsatured dicarboxylic acid cyclic anhydrides illustrated by maleic anhydride, and water. Mixture of the reactants and heating cause chemical interaction, evolution of carbon dioxide, ethylenic polymerization of intermediate reaction product, crosslinking, foaming and hardening of the resin. Cell formation is caused by carbon dioxide and water vapor in the resin reaction product. Resin foam products are infusible and insoluble in usual solvents and resist ignition and burning in air.
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