Thermosoftening phenyl siloxane glasses prepared via sol concentration

Abstract Thermosoftening phenyl polysiloxane glasses have been prepared by concentration of the corresponding sol above the melting temperature of the resultant materials, which we call the ‘sol concentration method’ (SCM). Because the glass melt is directly obtained without a gelation process, a remarkable shortening of the process time and suppression of crack formation in the sol–gel transition region have been realized. That is the whole process time of the SCM (about 24 h) is much shorter than that of the conventional sol–gel process (about 10 days). Thermosoftening phenyl polysiloxane glasses with high transparency in the UV region were obtained by the SCM.