Synthesis of MQ silicone resins through hydrolytic condensation of ethyl polysilicate and hexamethyldisiloxane

MQ silicone resins were synthesized through hydrolytic condensation of ethyl polysilicate and hexamethyldisiloxane. The structure of the MQ resins was characterized by NMR and GPC. The concentration of an acid catalyst was essential for the capping of functional groups with the monofunctional units. The acid-catalyzed resins had a narrow molecular weight distribution. After postcondensation catalyzed by a base, the molecular weight distribution became bimodal. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 1753–1757, 1998