Claims
- 1. 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.
- 2. The method of claim 1 in which said monomer is selected such that the linear polymer chains which it forms grow to degrees of polymerization in excess of about 100 before the electrophilic character of said reactive end groups is capable of being reversed by exposure to remaining monomer units acting as chain transfer agents.
- 3. The method of claim 1 in which said chain transfer agents are not introduced into said reaction vessel until after the polymerization has been allowed to proceed for a time sufficient to yield linear polymer chains of a desired degree of polymerization.
- 4. The method of claim 1 in which said compound having multiple reactive sites comprises one or more of the group consisting of linear polymers, branched polymers, cross-linked polymers, and dendritic polymers.
- 5. A composition of matter comprising a polymer prepared by the method of claim 1.
- 6. The composition of claim 5 having a molecular weight of about 1,000,000 or above.
- 7. The composition of claim 5 wherein the polymer is polyethyloxazoline.
- 8. The composition of claim 5 wherein the polymer is polyethyleneimide.
CLAIM OF PRIORITY
This is a continuation of PCT Application No. PCT/US98/02838, filed Feb. 17, 1998, which claims priority to U.S. Provisional Application No. 60/038,727, filed Feb. 18, 1997, to each of which this application claims priority.
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Provisional Applications (1)
|
Number |
Date |
Country |
|
60/038727 |
Feb 1997 |
US |
Continuations (1)
|
Number |
Date |
Country |
Parent |
PCT/US98/02838 |
Feb 1998 |
US |
Child |
09/365609 |
|
US |