Thermosetting shape memory polymers with ability to perform repeated molecular scale healing
A composition comprising thermoset shape memory polymer and a composition for molecular scale healing is disclosed; the composition has the ability to resolve structural defects by a close-then-heal mechanism. In use the shape memory polymer serves to bring opposing surfaces in a structural defect into proximity, whereafter heating the molecular scale healing composition to a level at or above its melting point allows for molecular scale healing. The composition has the ability to close macroscopic defects, and to do so repeatedly even if another wound occurs in a previously healed area.
1. A composite which comprises:
i) a thermoset shape memory polymer matrix, and,
ii) a thermoplastic polymer dispersed throughout said matrix, and,
iii) microballoons.
2. The composite of claim 1 , wherein said thermoplastic polymer comprises particles of said thermoplastic polymer.
3. The composite of claim 1 , wherein the melting temperature of said thermoplastic polymer is lower than the decomposition temperature of the thermoset matrix.
4. The composite of claim 1 , wherein said thermoset shape memory polymer is an epoxy.
5. The composite of claim 1 , wherein said thermoplastic polymer comprises 25% or less of the volume of the composite.
6. The composite of claim 1 , further comprising that the composite is programmed to a volume less than a native volume of the composite.
7. A product prepared in accordance with claim 6 wherein the programming step comprises programming at a temperature above the glass transition temperature of said composite.
8. A composite which comprises:
i) a polystyrene thermoset shape memory polymer matrix, and,
ii) a thermoplastic polymer dispersed throughout said matrix.
9. A method for preparing programmed shape memory polymer composite:
A) mixing a matrix of a thermoset shape memory polymer with a thermoplastic polymer and microballoons, whereby a composite is formed; and,
B) programming the entire composite to a volume less than a native expanded volume of said composite.
10. The method of claim 9 wherein the programming step comprises programming at a temperature above the glass transition temperature of said composite.
11. The method of claim 9 wherein the programming step comprises two-dimensional programming.
12. The method of claim 11 wherein the programming step comprises three-dimensional programming.
13. The method of claim 9 wherein the mixing step comprises mixing a thermoset shape memory polymer which is an epoxy.
14. The method of claim 9 wherein the mixing step comprises mixing a thermoplastic polymer which comprises 25% or less of the volume of the resulting composite.
15. The method of claim 9 wherein the mixing step comprises mixing a thermoplastic polymer which is in fibrous form, whereby thermoplastic polymer fibers become dispersed throughout said matrix.
16. The method of claim 9 wherein the mixing step comprises mixing a thermoplastic polymer which is in particles, whereby the thermoplastic polymer particles become dispersed throughout said matrix.
17. A method for preparing a programmed shape memory polymer composite:
A) mixing a matrix of a polystyrene thermoset shape memory polymer with a thermoplastic polymer, whereby a composite is formed; and,
B) programming the entire composite to a volume less than a native expanded volume of said composite.
18. A programmed shape memory polymer composite produced by a process comprising:
A) mixing a polystyrene thermoset shape memory polymer matrix with a thermoplastic polymer, whereby a composite is formed having a native volume; and
B) programming the entire composite to a volume less than the native volume of said composite.
19. A programmed shape memory polymer composite produced by a process comprising:
A) mixing a thermoset shape memory polymer matrix with a thermoplastic polymer and microballoons, whereby a composite is formed having a native volume; and
B) programming the entire composite to a volume less than the native volume of said composite.
20. A product prepared in accordance with claim 19 wherein the mixing step comprises mixing a thermoplastic polymer which is in particles, whereby the thermoplastic polymer particles become dispersed throughout said thermoset polymer matrix.
21. A product prepared in accordance with claim 19 wherein the programming step comprises two dimensional programming.
22. A product prepared in accordance with claim 19 , wherein the programming step comprises programming at a temperature above the glass transition temperature of said composite.
23. A product prepared in accordance with claim 19 , wherein the mixing step comprises mixing a thermoset shape memory polymer which is an epoxy.
24. A product prepared in accordance with claim 19 , wherein the mixing step comprises mixing a thermoplastic polymer which comprises 25% or less of the native volume of the resulting composite.