摘要 |
New solvents have been found for certain poly(parabanic acids) and poly(iminoimidazolidinediones). Epihalchydrins and glycidyl acrylate have been found to be solvents. Cellular films are produced by immersing films of the polymer solutions in aprotic anti-solvents such as aliphatic katones, esters, hydrocarbons, halogenated hydrocarbons and ethers. |