Ordered architectures in acrylic polymers
Polymers having ordered architectures and one or more reactive functional groups incorporated in select blocks or regions of the polymer in particular proportions relative to other regions in the polymer, are described. The polymers are well suited for use in adhesive compositions, and particularly for pressure sensitive adhesive compositions. In addition, various methods for forming the noted polymers and adhesive compositions utilizing the ordered polymers are disclosed.
1. A method of preparing a pressure sensitive adhesive composition, the method comprising:
forming an ordered polymer by living polymerization, whereby the ordered polymer comprises at least two different blocks, including one or more blocks A placed at a first region within the polymer and one or more blocks B placed at a second region within the polymer, and at least one reactive functional group apportioned between the blocks A and B wherein an amount of the at least one reactive functional group in both blocks A and B is apportioned between the blocks A and B in an apportionment ratio of from about 6:1 to about 10,000:1;
crosslinking the ordered polymer by mixing the ordered polymer with an amount of a crosslinking agent;
drying the crosslinked ordered polymer,
wherein the first region is an end region of the polymer and the second region is a middle region of the polymer.
2. The method of claim 1 wherein the apportionment ratio is within the range of from 6:1 to 1,000:1.
3. The method of claim 1 wherein the apportionment ratio is within the range of from 6:1 to 100:1.
4. The method of claim 1 wherein the polymer has a number average molecular weight of from about 10,000 to about 300,000.
5. The method of claim 1 wherein the polymer has a number average molecular weight of from about 50,000 to about 200,000.
6. The method of claim 1 wherein the polymer has a number average molecular weight of from about 100,000 to about 150,000.
7. The method of claim 1 wherein the amount of the crosslinking agent is from 0.05% to 5%.
8. The method of claim 1 wherein the amount of the crosslinking agent is from 0.075% to 2%.
9. The method of claim 1 wherein the amount of the crosslinking agent is from 0.1% to 1.5%.