Vegetable oil based viscoelastic polymers that display photoresponsive rheological and adhesive properties
Photoresponsive polymers that comprise a unit derived from an amide functional diol compound that includes a coumarin group are provided. Advantageously, the photoresponsive groups of the photoresponsive polymers may be used to control the viscosity of the photoresponsive polymer. The photoresponsize polymers may also include units derived from amide functional diol compounds with include a fatty acid chain or a polyethylene glycol chain. The photoresponsive polymers may be used for 3d printing. When an adhesive group is added to a photoresponsive polymer they may be used as an adhesive. Adhesive groups include catechol groups.
1. A viscoelastic polymer comprising the formula
where each R 1 is individually a hydrocarbon group, R 2 is a hydrocarbon group; each R 3 is individually a hydrogen atom, a halogen atom or an alkoxy group; Y is an oxygen atom or an amide group; each R 4 is individually a hydrocarbon group or polyoxyethylene group having a molecular weight of from about 440 to about 600; R 5 is a saturated or unsaturated aliphatic hydrocarbon chain having from 6 to 28 carbon atoms in the chain; 1 is from about 1 to about 323; and n is from about 1 to about 400.
2. The polymer of claim 1 , further comprising at least one unit derived from an amide functional diol compound that includes a catechol group, wherein the polymer is defined by the formula
where each R 1 is individually a hydrocarbon group, R 2 is a hydrocarbon group; each R 3 is individually a hydrogen atom, a halogen atom or an alkoxy group, and Y is an oxygen atom or an amide group; each R 4 is individually a hydrocarbon group or polyoxyethylene group having a molecular weight of from about 440 to about 600; R 5 is a saturated or unsaturated aliphatic hydrocarbon chain having from 6 to 28 carbon atoms in the chain; each R 7 is individually a hydrogen atom or an organic group, or where the two R 7 groups combine to make a single organic group; 1 is about 1 to about 100 units; n is about 2 to about 300 units; and o is about 1 to about 200 units.
3. The polymer of claim 1 , where the lap shear strength is greater than 300 kPa.
4. The polymer of claim 1 , where the lap shear strength is less than 10 kPa.
5. The polymer of claim 1 , where the polymer is a liquid.
6. The polymer of claim 1 , where the polymer is a solid.
7. The polymer of claim 1 , where the polymer further includes a unit defined by the formula
where each R 1 is individually a hydrocarbon group and p is from about 3 to about 30 units.
8. The polymer of claim 1 , where 1 is from about 1 to about 200; and n is from about 7 to about 200.
9. The polymer of claim 1 , where R 5 is selected from the group consisting of
10. The polymer of claim 1 , where the polymer is characterized by a number average molecular weight of from about 12.6 to 20 kDa.
11. The polymer of claim 1 , where the polymer is characterized by a weight average molecular weight of from about 14.7 to about 37 kDa.