Hybrid silane dendrimer-star polymers

A hybrid dendrimer-star polymer, comprising:

• (i) a silane-or carbosilane-based, periphery-modified dendrimer, comprising:
• a) an inner structure having a central silane nucleus and, optionally, multiple carbosilane branches extending outwardly from the nucleus in a repetitive generational manner yielding silane termini;
• and, attached to the silane or silane termini by a hydrolysis-resistant bond;
• b) bridge moieties comprising groups selected from alkyl of at least two C atoms, cycloalkyl, aryl including aralkyl and alkaryl, and polyether and polysulfide of up to about 6 repeating units, the moieties having reactive group sites;
• and
• (ii) outer arms comprising polymer chains selected from polyethers, polysulfides, polyesters and copolymers thereof, the arms being attached to the dendrimer at the reactive group sites.

A process of preparing a hybrid dendrimer-star polymer including a modified silane or carbosilane dendrimer and selected polymer outer arms, comprising:

• a) attaching bridge moieties to reactive silane sites in a silane or carbosilane dendrimer, the bridge comprising a group selected from alkyl, cycloalkyl, aryl, aralkyl, alkaryl, small polyether and small polysulfide, the bridges having reactive groups thereon;
• and
• b) reacting a selected form of the bridge reactive groups with one of:
• (i) monomer selected from alkylene oxide, alkylene sulfide, alkylene glycol, alkylene dithiol, and hydroxyalkanoic acid and lactone thereof, under polymerization conditions, said selected form serving as initiator, to form polymer arm attached to the bridge;
• and
• (ii) prepolymer selected from polyether, polysulfide,polyester, and copolymers thereof to attach prepolymer to the bridge, thereby to form the star polymer.