PREPARATION OF POLY(AMIDEIMIDE SILOXANE) FROM TRIMELLITIC ANHYDRIDE CHLORIDE, OXYLENE DIAMINE AND OLIGO(DIMETHYLSILOXANE) DIAMINE

A novel poly(amideimide siloxane) block copolymer was prepared from ol igo(dimethylsiloxane), trimellitic anhydride chloride and oxylene diam ine using trimethylsilyl chloride as the reaction activator. Trimethyl silyl chloride enhanced the reactivity of oligo(dimethylsiloxane), res ulting in a higher yield and viscosity of the product. The high reacti vity of N-trimethylsilylated siloxane diamine stems from the silicon s igma-pi effect, and a nucleophilic addition-elimination reaction is pr oposed. The addition of a small amount of N-methylpyrrolidone in tetra hydrofuran led to a higher yield. The temperature of 10% weight loss f or the product exceeded 355 degrees C according to thermogravimetric a nalysis data. A transient change in the contact angle of water on the sample surface was observed, suggesting surface segregation of the hyd rophobic component in the polymer.