3d printable lquid crystalline elastomers with tunable shape memory behavior and bio-derived renditions

Patent metadata

Field	Value
Publication number	US-2016289491-A1
Application number	US-201615091182-A
Country	US
Kind code	A1
Filing date	Apr 5, 2016
Priority date	Apr 6, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

Described herein are liquid crystalline elastomer compositions comprising aromatic epoxy units crosslinked with alkylene diacid units having alkylene segments containing at least one methylene unit, and/or aromatic epoxy units crosslinked with polyphenolic units, wherein the aromatic epoxy units and alkylene diacid units and/or polyphenolic units are in a molar ratio that results in the liquid crystalline elastomer composition exhibiting a glass transition temperature (T g ) and a thermal stability of the liquid crystalline phase (T lc ) that make them particularly suitable as shape memory materials and for use in methods of additive manufacturing. Methods for producing these compositions and their use in additive manufacturing processes are also described.

First claim

What is claimed is:

1 . A liquid crystalline elastomer composition comprising aromatic epoxy units crosslinked with alkylene diacid units having alkylene segments containing at least one methylene unit, wherein the aromatic epoxy units and alkylene diacid units are in a molar ratio that results in the liquid crystalline elastomer composition exhibiting a glass transition temperature (T g ) of at least 25° C. and a thermal stability of the liquid crystalline phase (T lc ) of at least 50° C.

2 . The composition of claim 1 , wherein the liquid crystalline elastomer composition exhibits a degree of liquid crystallinity (ΔH lc ) of at least 10 J/g.

3 . The composition of claim 1 , wherein said aromatic epoxy units possess at least two phenyl rings connected by a covalent bond or fused with each other.

4 . The composition of claim 1 , wherein said aromatic epoxy units possess at least three phenyl rings connected by a covalent bond and/or fused with each other.

5 . The composition of claim 1 , wherein said alkylene diacid units have alkylene segments containing at least three and up to ten methylene units.

6 . The composition of claim 1 , wherein said aromatic epoxy units possess at least two phenyl rings connected by a covalent bond or fused with each other and said alkylene diacid units have alkylene segments containing at least three and up to ten methylene units.

7 . The composition of claim 1 , wherein said molar ratio is a molar ratio of aromatic epoxy units to alkylene diacid units of above 0.5 and up to 1.

8 . The composition of claim 1 , wherein said T g is at least 25° C. and up to 70° C. and said T lc is at least 50° C. and up to 150° C.

9 . A method of producing a liquid crystalline elastomer composition, the method comprising crosslinking aromatic epoxy molecules with alkylene diacid molecules containing at least one methylene unit at a processing temperature of at least 120° C. to 250° C., wherein the aromatic epoxy molecules and alkylene diacid molecules are in a molar ratio that results in the liquid crystalline elastomer composition exhibiting a glass transition temperature (T g ) of at least 25° C. and a thermal stability of the liquid crystalline phase (T lc ) of at least 50° C.

10 . The method of claim 9 , wherein the liquid crystalline elastomer composition exhibits a degree of liquid crystallinity (ΔH lc ) of at least 10 J/g.

11 . The method of claim 9 , wherein said aromatic epoxy molecules possess at least two phenyl rings connected by a covalent bond or fused with each other.

12 . The method of claim 9 , wherein said aromatic epoxy molecules possess at least three phenyl rings connected by a covalent bond and/or fused with each other.

13 . The method of claim 9 , wherein said alkylene diacid molecules have alkylene segments containing at least three and up to ten methylene units.

14 . The method of claim 9 , wherein said aromatic epoxy molecules possess at least two phenyl rings connected by a covalent bond or fused with each other and said alkylene diacid molecules have alkylene segments containing at least three and up to ten methylene units.

15 . The method of claim 9 , wherein said molar ratio is a molar ratio of aromatic epoxy molecules to alkylene diacid molecules of above 0.5 and up to 1.

16 . The method of claim 9 , wherein said T g is at least 25° C. and up to 70° C. and said T lc is at least 50° C. and up to 150° C.

17 . A method of additive manufacturing, the method comprising feeding a liquid crystalline elastomer composition into an additive manufacturing device to produce an object made of said liquid crystalline elastomer composition, wherein said liquid crystalline elastomer composition comprises aromatic epoxy units crosslinked with alkylene diacid units having alkylene segments containing at least one methylene unit, wherein the aromatic epoxy units and alkylene diacid units are in a molar ratio that results in the liquid crystalline elastomer composition exhibiting a glass transition temperature (T g ) of at least 25° C. and a thermal stability of the liquid crystalline phase (T lc ) of at least 50° C.

18 . The method of claim 17 , wherein the liquid crystalline elastomer composition exhibits a degree of liquid crystallinity (ΔH lc ) of at least 10 J/g.

19 . The method of claim 17 , wherein said aromatic epoxy units possess at least two phenyl rings connected by a covalent bond or fused with each other.

20 . The method of claim 17 , wherein said aromatic epoxy units possess at least three phenyl rings connected by a covalent bond and/or fused with each other.

21 . The method of claim 17 , wherein said alkylene diacid units have alkylene segments containing at least three and up to ten methylene units.

22 . The method of claim 17 , wherein said aromatic epoxy units possess at least two phenyl rings connected by a covalent bond or fused with each other and said alkylene diacid units have alkylene segments containing at least three and up to ten methylene units.

23 . The method of claim 17 , wherein said molar ratio is a molar ratio of aromatic epoxy units to alkylene diacid units of above 0.5 and up to 1.

24 . The method of claim 17 , wherein said T g is at least 25° C. and up to 70° C. and said T lc is at least 50° C. and up to 150° C.

25 . A liquid crystalline elastomer composition comprising aromatic epoxy units crosslinked with polyphenolic units having at least four phenolic groups, wherein the phenolic groups in the polyphenolic units and epoxy groups in the aromatic epoxy units, as crosslinked, are in a molar ratio of 3:2 to 1:2.

26 . The composition of claim 25 , wherein said aromatic epoxy units possess at least two phenyl rings connected by a covalent bond or fused with each other.

27 . The composition of claim 25 , wherein said aromatic epoxy units possess at least three phenyl rings connected by a covalent bond and/or fused with each other.

28 . A method of additive manufacturing, the method comprising feeding a liquid crystalline elastomer composition into an additive manufacturing device to produce an object made of said liquid crystalline elastomer composition, wherein said liquid crystalline elastomer composition comprises aromatic epoxy units crosslinked with polyphenolic units having at least four phenolic groups, wherein the phenolic groups in the polyphenolic units and epoxy groups in the aromatic epoxy units, as crosslinked, are in a molar ratio of 3:2 to 1:2.

29 . The method of claim 28 , wherein said aromatic epoxy units possess at least two phenyl rings connected by a covalent bond or fused with each other.

30 . The method of claim 28 , wherein said aromatic epoxy units possess at least three phenyl rings connected by a covalent bond and/or fused with each other.

Assignees

• Ut Battelle Llc
• Univ Washington State

Inventors

• Li Yuzhan
• Rios Orlando
• Johs Alexander
• Kessler Michael Richard

Classifications

• C08L63/00

  Compositions of epoxy resins; Compositions of derivatives of epoxy resins · CPC title

• C08G59/686 Primary

  containing nitrogen · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• C08G59/4207

  aliphatic · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title