about 80 u00b0 c and about 140 u00b0 c a catalyst may optionally be employed in the coupling reaction useful catalysts include the well known tin and amine catalysts such as dibutyltin dilaurate stannous octoate dabco amine catalyst and the like coupling monols with polyacyl compounds is typically carried out at elevated temperature preferably between about 80 u00b0 c and about 220 u00b0 c more preferably between about 100 u00b0 c and about 180 u00b0 c a catalyst is optionally employed in the coupling reaction and suitable catalysts include but are not limited to caustic titanium alkoxides tin carboxylates and the like the coupling catalyst if used is employed in a catalytically effective amount preferably between about 0 001 and about 1 illustrative of the flexibility of the process of the present invention is the use of coupling agents with more than two hydroxyl reactive groups this yields polyethers or polyesters with three or more branches and provides a means for crosslinking when these branched polyethers or polyesters are used alone or in combination with polyethers or polyesters coupled with diisocyanates or diacyl compounds beneficial property improvement for the cured polymer is suitably attained the coupled terminally unsaturated polyethers or polyesters can be utilized with other curable polymers or preferably converted to curable silyl terminated polymers reaction of the terminally unsaturated coupled polyether or polyester with an alkyldialkoxysilane or the.