| Abstract: | Silylated aromatic polyureas were synthesized by the polyaddition of N,N′-bis(trimethylsilyl)-substituted aromatic diamines to aromatic diisocyanates in various organic solvents at a temperature ranging from 30 to 100°C. Colorless and transparent films of the silylated polyureas were obtained by casting directly from these solutions in a dry nitrogen atmosphere. The silylated polyureas thermally decomposed at around 200°C and were easily desilylated with alcohol to convert to almost amorphous aromatic polyureas having inherent viscosities of 0.4–1.0 dL/g. The polyureas exhibited better solubility in organic solvents such as N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and dimethyl sulfoxide and had somewhat lower thermal decomposition temperatures (around 300°C) than the polyureas prepared by a conventional method from the parent aromatic diamines and diisocyanates. |
