Higher order star polymers having multiple polyisobutylene arms radiating from a condensed core of siloxanes and a method for the synthesis thereof

摘要

The synthesis and characterization of novel higher order, multi-arm star polymers comprising polyisobutylene arms connected to condensed cyclosiloxane cores are described. The synthesis has been achieved by hydrosilating olefin-capped (e.g., allyl- or isopropenyl-terminated) polyisobutylene with hydrogencyclosiloxanes carrying a plurality of Si-H groups and simultaneously and competitively converting SiH functions, in the presence of moisture, to Si-OH groups to rapidly self-condense or react with SiH groups to form coupled cyclosiloxane cores via core-core coupling. Thus, higher order stars having many more arms than first order stars can be formed.