Room temperature polymer crosslinking using 1-functionalized benzocyclobutene
Specific benzocyclobutenes serve as intramolecular or intermolecular or both intramolecular or intermolecular crosslinkers. The benzocyclobutenes can be incorporated into polymers post polymerization or can be provided as monomers that participate in homopolymerization or copolymerization with other monomer to create the polymers having benzocyclobutenes that are exploited to carry out the crosslinking. At least some of the benzocyclobutenes taught herein can be used to carry out crosslinking a ambient temperatures.
1. A method of forming a copolymer comprising the steps of:
copolymerizing a first monomer and a second monomer, the second monomer being selected according to the following chemical formula:
wherein R1 is selected from the group consisting of:
wherein n is 0 or more; or R1 is non-existent, or
wherein Z is any linkage between the norbornene and the benzene ring; wherein R2 is selected from CH3, aliphatic groups, cycloaliphatic groups, and aromatic groups, wherein A is either non-existent or is selected from any structural unit that is incapable of reacting with a nucleophile, and crosslinking the resultant copolymer at a temperature from 15.5° C. to 35° C.
2. The method of claim 1 wherein the first monomer is selected from the group consisting of styrene, acrylates, methacrylates, acrylamides, methacrylamides, cyclopentenes, norbornenes, and cyclooctadienes.
3. The method of claim 1 wherein R1 is HC═CH2, and copolymerization is carried out through radical polymerization.
4. The method of claim 1 wherein R1 is:
and copolymerization is carried out through radical polymerization.
5. The method of claim 1 wherein R1 is
and copolymerization is carried out through radical polymerization.
6. The method of claim 1 wherein R1 is
and copolymerization is carried out through ring-opening metathesis.
7. The method of claim 1 wherein said step of crosslinking occurs in the presence of a nucleophile, wherein the nucleophile is selected from the group consisting of BuLi, sec-BuLi, NaOMe, nBuNa, and LiOMe.
8. The method of claim 7 wherein the crosslinking is intermolecular crosslinking.
9. The method of claim 7 wherein the crosslinking is intramolecular crosslinking.
10. The method of claim 1 wherein the second monomer has the formula: