Patent ID: 6632889
Filing Date: 2003-10-14
Classification: C08F,C08G

Abstract:
A method for forming a branched polyethyloxazoline or polyethyleneimide polymer capable of achieving high molecular weights comprising:forming a plurality of growing linear polymer chains by polymerizing, as a monomer, 2-ethyloxazoline which is protected against branching and which forms a reactive end group, upon contact with a carbonium ion, which is in a first condition which is electrophilic, and which at least during a portion of the polymerization reaction is susceptible of reversing its electrophilic character to nucleophilic by reaction with more of said monomer functioning as a chain transfer agent; exposing the growing linear polymer chains to the chain transfer agent to cause the reactive end group of at least a first growing linear polymer chain to reverse its electrophilic character, whereby a non-reversed reactive end group on a second growing linear polymer chain reacts with said reversed reactive end group on said first growing linear polymer chain to create a branched polymer, and reverses said nucleophilic character of said revised reactive end group back to its first condition of electrophilic character, whereby it may continue adding monomer in a linear fashion; and quenching the polymerization by adding polyethyleneimine capable of reacting with said reactive end groups of said polymer chains when they are in said first condition of electrophilic character, whereby a branched polymer is formed from said monomer which is protected against branching.