Synthesis,characterization, and applications of novel additives of polysiloxane containing N,N′‐bis(diphenylsilyl)tetraphenylcyclodisilazane

Three N,N′‐bis(diphenylsilyl)tetraphenylcyclodisilazane‐based derivatives, N,N′‐bis(3,3,3‐trimethyl‐1,1‐diphenyl‐disiloxanyl)tetraphenylcyclodisilazane, N‐(3,3‐dimethyl‐1,1‐diphenyl‐3‐vinyl‐disiloxanyl)‐N′‐(3,3,3‐trimethyl‐1,1‐diphenyl‐disiloxanyl)‐tetraphenylcyclodisilazane, and N,N′‐bis‐(3,3‐dimethyl‐1,1‐diphenyl‐3‐vinyl‐disiloxanyl) tetraphenylcyclodisilazane, were synthesized. These compounds were synthesized in an easy and effective route. X‐ray single‐crystal diffraction analyses showed that the four‐member rings were planar rings, and the structures are different with the different substitution. The compound N,N′‐bis‐(3,3‐dimethyl‐1,1‐diphenyl‐3‐vinyl‐disiloxanyl) tetraphenylcyclodisilazane was added to the silicone rubber as additive to enhance the thermal stability greatly increased the thermal stability of the silicone rubber, without altering the glass transition temperature. The weight loss at 350°C in nitrogen atmosphere for 24 h reduced from 55.8% for 0 wt % to 9.8% for 10 wt % addition N,N′‐Bis‐(3,3‐dimethyl‐1,1‐diphenyl‐3‐vinyl‐disiloxanyl)tetraphenylcyclodisilazane. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007