Aminolysis of cured siloxane polymers

摘要

The rate of the aminolysis of polydimethylsiloxane networks under ambient temperature was drastically enhanced by adding ethanol to the KOH/DEA solution. The results are attributed to the complete dissolution of potassium hydroxide and the elim- ination of the heterogeneous interfacial diffusion resistance. A mechanism is proposed to elucidate the need of a base as the catalyst and the effect of the second nucleophile. When excess of ethanol was added, the dissolution time of the silicone networks was increased as a result of the competition of pairing the second base and the nucleophiles. The product was composed of 85 cyclic oligomers. The displacement of -NEt_2 by -OEt group is evidenced by the results of NMR analyses of the final polymer product.