Oligomer-modified layered inorganic compounds and their use in nanocomposites
View Patent ↗Intercalates, exfoliates thereof, and nanocomposite compositions are formed by intercalating a layered silicate material, e.g., a phyllosilicate, with an oligomer or polymer intercalant that is a reaction product of at least one diamine with at least one dicarboxylic acid, to form a polyamide oligomer containing a xylylenediamine component. The oligomer or polymer may be formed in-situ by contacting the layered phyllosilicate with polymerizable monomer reactants using conditions to cause reaction and polymerization in the intercalating composition and intercalation of the resulting oligomer and/or polymer, between platelet layers of the phyllosilicate. An amine functionality of the oligomer or polymer is protonated for ion-exchange with interlayer cations of the phyllosilicate to bond the intercalant to the phyllosilicate platelet, at the protonated amine, at a negative charge site previously occupied by the interlayer cations.
1. An intercalate, capable of being exfoliated, formed by contacting a layered phyllosilicate material with an intercalant, without prior sorption of an onium ion spacing agent, wherein the intercalant is an oligomer or polymer surface modifier that is a protonated reaction product consisting of at least one diamine and at least one dicarboxylic acid, said reaction product having at least one amine group that is protonated for ion-exchange with an interlayer cation of the layered phyllosilicate material, to achieve ion-exchange of the protonated amine group of the intercalant surface modifier with the interlayer cation of the layered phyllosilicate material, between adjacent spaced layers of the layered phyllosilicate material, to expand the spacing between a predominance of the adjacent platelets of said layered material at least about 5 Å, when measured after sorption of intercalant surface modifier.
2. An intercalate in accordance with claim 1 , wherein the intercalant contacts the layered phyllosilicate material to form an intercalating composition, and the concentration of intercalant surface modifier in said intercalating composition is at least about 0.1% by weight, based on the weight of water, organic solvent for the surface modifier, and intercalant surface modifier in the intercalating composition.
3. An intercalate in accordance with claim 2 , wherein the intercalant is an oligomer and the concentration of the intercalant surface modifier in said intercalating composition is at least about 15% by weight, based on the dry weight of the phyllosilicate in the intercalating composition.
4. An intercalate in accordance with claim 3 , wherein the concentration of the intercalant surface modifier in said intercalating composition is at least about 20% by weight, based on the dry weight of the phyllosilicate in the intercalating composition.
5. An intercalate in accordance with claim 4 , wherein the concentration of the intercalant surface modifier in said intercalating composition is at least about 30% by weight based on the dry weight of the phyllosilicate in the intercalating composition.
6. An intercalate in accordance with claim 5 , wherein the concentration of the intercalant surface modifier in said intercalating composition in the range of about 50% to about 80% by weight.
7. An intercalate in accordance with claim 3 , wherein the concentration of the intercalant surface modifier in the intercalating composition is at least about 16% by weight.
8. An intercalate in accordance with claim 7 , wherein the concentration of the intercalant surface modifier in the intercalating composition is in the range of about 16% to about 200% by weight.
9. An intercalate in accordance with claim 8 , wherein the concentration of the intercalant surface modifier in the intercalating composition is in the range of about 16% to less than about 35% by weight.
10. An intercalate in accordance with claim 8 , wherein the concentration of the intercalant surface modifier in the intercalating composition is in the range of about 35% to less than about 55% by weight.
11. An intercalate in accordance with claim 8 , wherein the concentration of the intercalant surface modifier in the intercalating composition is in the range of about 55% to less than about 70% by weight.
12. A method of exfoliating a layered phyllosilicate material comprising:
contacting the layered silicate material with an intercalating composition comprising at least about 2% by weight of an oligomeric intercalant surface modifier, without prior sorption of an onium or silane coupling agent, wherein the intercalant is a protonated reaction product consisting of at least one diamine and one dicarboxylic acid, said reaction product having at least one amine group that is protonated for ion-exchange with an interlayer cation of the layered phyllosilicate material, to intercalate the oligomeric intercalant surface modifier between adjacent silicate platelets of the layered phyllosilicate material to form an intercalate; and
separating the platelets of the intercalate.
13. The method of claim 12 , wherein the intercalate is exfoliated into a predominance of individual platelets.
14. A method in accordance with claim 12 , wherein the amount of intercalant surface modifier intercalated into the phyllosilicate material is 10-200% intercalant surface modifier, based on the dry weight of the phyllosilicate material.
15. A method in accordance with claim 12 , wherein the amount of intercalant surface modifier intercalated into the phyllosilicate material is about 15% to about 80%, based on the dry weight of the phyllosilicate material.
16. An intercalate, capable of being exfoliated, formed by contacting a layered phyllosilicate material with an intercalating composition including an intercalant oligomer or polymer surface modifier that is a protonated reaction product consisting of at least one diamine and at least one dicarboxylic acid, without an onium ion spacing agent, said protonated reaction product having at least one amine group that is protonated for ion-exchange with an interlayer cation of the layered phyllosilicate material, to form an oligomer intercalant surface modifier and to achieve ion-exchange of the protonated amine group of the oligomer intercalant surface modifier with the interlayer cation of the layered phyllosilicate material, between adjacent spaced layers of the layered phyllosilicate material, to expand the spacing between a predominance of the adjacent platelets of said layered phyllosilicate material at least about 5 Å, when measured after sorption of intercalant surface modifier.
17. An intercalate in accordance with claim 16 , having formula 1 or 2 as follows, wherein “B” represents a xylylenediamine-component-containing Base, and “A” represents a dicarboxylic acid, wherein at least one of the B components includes a protonated amine functionality, and wherein n=1-20; and m=0-20:
B(AB) n 1
B(AB) m A 2.
18. An intercalate in accordance with claim 17 , wherein B is a xylylenediamine comprising at least 60 mole % m-xylylenediamine.
19. An intercalate in accordance with claim 18 , wherein A is selected from adipic acid or succinic acid.
20. An intercalate in accordance with claim 16 , wherein the intercalant has a structural formula I, II, III, IV, V, VI, or a combination of any two or more:
21. An intercalate, capable of being exfoliated, comprising a layered silicate material and a protonated intercalant surface modifier, the protonated intecalant surface modifier that is a protonated reaction product consisting of at least one diamine and at least one dicarboxylic acid, polymerized and amine-protonated while in contact with the layered silicate material, wherein the diamine comprises a xylylenediamine, wherein the protonated amine group of the intercalant surface modifier is ion-exchanged with an interlayer cation of the layered silicate material, between adjacent spaced layers of the layered silicate material, wherein the spacing between a predominance of the adjacent platelets of said layered material expanded at least about 10 Å, when measured after sorption of the protonated intercalant surface modifier, without prior sorption of an onium ion or silane coupling agent.
22. An intercalate in accordance with claim 21 , wherein the concentration of the xylylenediamine component in the intercalant surface modifier is at least 50 mole %.
23. An intercalate in accordance with claim 22 , wherein the concentration of the xylylenediamine component in the intercalant surface modifier is at least 70 mole %.
24. An intercalate in accordance with claim 21 , wherein the xylylenediamine component in the intercalant surface modifier comprises at least 60 mole % m-xylylenediamine.
25. An intercalate in accordance with claim 24 , wherein the xylylenediamine component in the intercalant surface modifier comprises at least 70 mole % m-xylylenediamine.
26. An intercalate in accordance with claim 25 , wherein the xylylenediamine component in the intercalant surface modifier comprises at least 80 mole % m-xylylenediamine.
27. An intercalate in accordance with claim 26 , wherein the xylylenediamine component in the intercalant surface modifier comprises at least 95 mole % m-xylylenediamine.
28. An intercalate in accordance with claim 24 , wherein the xylylenediamine component in the intercalant surface modifier comprises up to about 40 mole % p-xylylenediamine.
29. An intercalate in accordance with claim 28 , wherein the dicarboxylic acid component in the intercalant surface modifier is selected from the group consisting of adipic acid, sebacic acid, suberic acid, undecanoic acid, dodecanedioic acid, eicosanedioic acid, terephthalic acid, isophthalic acid, and combinations thereof.
30. An intercalate in accordance with claim 21 , wherein the dicarboxylic acid component in the intercalant surface modifier comprises at least 50 mole % alpha, omega-straight chain aliphatic dicarboxylic acid.
31. An intercalate in accordance with claim 30 , wherein the dicarboxylic acid component in the intercalant surface modifier comprises at least 60 mole % alpha, omega-straight chain aliphatic dicarboxylic acid.
32. An intercalate in accordance with claim 31 , wherein the dicarboxylic acid component in the intercalant surface modifier comprises at least 70 mole % alpha, omega-straight chain aliphatic dicarboxylic acid.
33. An intercalate in accordance with claim 30 , wherein the alpha, omega-straight chain aliphatic dicarboxylic acid component in the intercalant surface modifier has 6 to 24 carbon atoms.
34. An intercalate in accordance with claim 33 , wherein the dicarboxylic acid component in the intercalant surface modifier comprises at least 80 mole % alpha, omega-straight chain aliphatic dicarboxylic acid.
35. A method of exfoliating layered silicate material in accordance with claim 12 , wherein the intercalate is selected from the group consisting of formulas I, II, III, IV, V, VI and a combination of any two or more: