Abstract: This invention relates to a novel class of organosilanes. The characteristic feature of these silanes is the presence of a hydantoin residue that is bonded to silicon through an alkylene group.

Abstract: A portion of the tin compounds conventionally employed to cure polymer compositions containing hydroxyl and isocyanate groups can be replaced by salts or chelated coordination complexes of divalent copper, zinc, nickel, iron, cobalt or vanadium without any substantial decrease in cure rate or solvent resistance of the cured coating.

Abstract: The properties of polymeric compositions can be improved by the presence of a polysiloxane unit of formula ##STR1## where Q is a substituted or unsubstituted aromatic group,Z is ##STR2## D is unsubstituted or substituted hydrocarbylene R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 each, independently, is unsubstituted or substituted hydrocarbyl.x, y and z each independently has a value from 0 to 100.Polyimides containing these units display improved solubility and adhesion; they are useful, among other things as protective coatings.