Abstract: The present invention relates to a process for the preparation of trioganosilyl-terminated polydiorganosiloxanes by basic polymerization of cyclic diorganopolysiloxanes and triorganosilyl-terminated siloxanes, wherein, before the polymerization, a part of the cyclic diorganosiloxane is distilled off in the presence of the polymerization catalyst at a temperature which is at least 10.degree. C. below the polymerization temperature.

Abstract: In a plastic organosiloxane molding composition which in the absence of water is capable of being stored and in the presence of moisture is cross-linked to a rubber, the composition comprising a hydroxypolydiorganosiloxane, a nitrogen base and heavy metal compound as cross-linking catalyst, and a cross-linking agent, the improvement which comprises employing as the cross-linking agent a compound of the formula ##STR1## or a partial hydrolysis product thereof, wherein R is an optionally substituted alkyl, alkenyl or aryl group,R.sub.1 is hydrogen or R,R.sub.2 is an acyl, carbalkoxy or carbaroxy group or R.sub.1,a is 1-3, andn is 0, 1 or 2 and a+n.ltoreq.3.Upon curing no unpleasant odors are given off upon decomposition of the cross-linking agent.