Liquid crystal elastomer compositions and methods of making the same

Patent metadata

Field	Value
Publication number	US-12319861-B2
Application number	US-202318166389-A
Country	US
Kind code	B2
Filing date	Feb 8, 2023
Priority date	Feb 8, 2022
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

A liquid crystal elastomer (LCE) formed from liquid crystalline monomers having 4-(6-(acryloyloxy)n-oxy)phenyl-4-(6-(acryloyloxy)m-oxy)benzoate (CnBAPE) as the mesogenic core. The LCEs have improved thermotropic characteristics, including lower thermotropic activation temperatures. The LCEs may also incorporate azobenzene to thereby also enhance the phototropic properties of the LCE.

First claim

We claim:

1. A liquid crystal elastomer, comprising:
a first liquid crystalline monomer having a first mesogenic core; and
a second liquid crystalline monomer having a second mesogenic core;
wherein the first mesogenic core comprises 4-(6-(acryloyloxy)n-oxy)phenyl-4-(6-(acryloyloxy)m-oxy)benzoate, with n being any one of pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and m being any one of pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl; and
wherein the second mesogenic core comprises 1,4-Bis[4-(n-acryloyloxybutyloxy)benzoyloxy]-2-methylbenzene, where the value of n is from 3 to 11.

2. The liquid crystal elastomer of claim 1 , wherein n and m in 4-(6-(acryloyloxy)n-oxy)phenyl-4-(6-(acryloyloxy)m-oxy)benzoate are hexyl.

3. The liquid crystal elastomer of claim 1 , wherein the molar ratio of 4-(6-(acryloyloxy)n-oxy)phenyl-4-(6-(acryloyloxy)m-oxy)benzoate to 1,4-Bis[4-(n-acryloyloxybutyloxy)benzoyloxy]-2-methylbenzene is about 1:1.

4. The liquid crystal elastomer of claim 1 , wherein a thermotropic actuation temperature of the liquid crystal elastomer is less than 50° C.

5. The liquid crystal elastomer of claim 1 , further comprising:
one or more thiol monomers.

6. The liquid crystal elastomer of claim 1 , further comprising:
at least one first thiol monomer serving as a chain extender; and
at least one second thiol monomer serving as a crosslinker.

7. The liquid crystal elastomer of claim 1 , further comprising:
a third liquid crystalline monomer having a third mesogenic core;
wherein the first mesogenic core, the second mesogenic core, and the third mesogenic core are all different.

8. The liquid crystal elastomer of claim 7 , wherein the second mesogenic core and the third mesogenic core each comprises 1,4-Bis[4-(n-acryloyloxybutyloxy)benzoyloxy]-2-methylbenzene, where the value of n is from 3 to 11.

9. The liquid crystal elastomer of claim 1 , wherein the liquid crystal elastomer is one of surface aligned, mechanically aligned or rheologically aligned.

10. The liquid crystal elastomer of claim 1 , further comprising:
an azobenzene.

11. The liquid crystal elastomer of claim 10 , wherein n and m in 4-(6-(acryloyloxy)n-oxy)phenyl-4-(6-(acryloyloxy)m-oxy)benzoate are hexyl.

12. The liquid crystal elastomer of claim 10 , wherein the value of n in 1,4-Bis[4-(n-acryloyloxybutyloxy)benzoyloxy]-2-methylbenzene is 6.

13. The liquid crystal elastomer of claim 10 , wherein the weight ratio of 4-(6-(acryloyloxy)n-oxy)phenyl-4-(6-(acryloyloxy)m-oxy)benzoate to 1,4-Bis[4-(n-acryloyloxybutyloxy)benzoyloxy]-2-methylbenzene is from about 1:1 to about 1:3.

14. The liquid crystal elastomer of claim 10 , wherein the liquid crystal elastomer is surface aligned.

15. A liquid crystal elastomer, comprising:
a liquid crystalline monomer having a mesogenic core;
wherein the mesogenic core comprises 4-(6-(acryloyloxy)n-oxy)phenyl-4-(6-(acryloyloxy)m-oxy)benzoate, with n being any one of pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and m being any one of pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl; and
wherein 4-(6-(acryloyloxy)n-oxy)phenyl-4-(6-(acryloyloxy)m-oxy)benzoate is the only mesogenic core present in the liquid crystal elastomer.

16. A liquid crystal elastomer, comprising:
a liquid crystalline monomer having a mesogenic core; and
one or more thiol monomers;
wherein the mesogenic core comprises 4-(6-(acryloyloxy)n-oxy)phenyl-4-(6-(acryloyloxy)m-oxy)benzoate, with n being any one of pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, and m being any one of pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl.

17. The liquid crystal elastomer of claim 16 , wherein the one or more thiol monomers comprises:
at least one first thiol monomer serving as a chain extender; and
at least one second thiol monomer serving as a crosslinker.

Assignees

• Univ Colorado Regents

Inventors

• White Timothy
• Hebner Tayler
• Mccracken Joselle
• Donovan Brian
• Bowman Christopher
• Bauman Grant

Classifications

• C09K2019/546

  creating a polymeric network · CPC title

• C09K2019/0448

  the end chain group being a polymerizable end group, e.g. -Sp-P or acrylate · CPC title

• C09K19/3809 Primary

  Polyesters; Polyester derivatives, e.g. polyamides · CPC title

• C09K19/04 Primary

  characterised by the chemical structure of the liquid crystal components {, e.g. by a specific unit} · CPC title