POLYMER EXFOLIATED PHYLLOSILICATE NANOCOMPOSITE COMPOSITIONS AND A PROCESS FOR THE PREPARATION THEREOF

Abstract

The present invention provides a polymer-phyllosilicate nanocomposite composition comprising (a) 10-99.95% by weight of a matrix polymer and (b) 0.05-90% by weight of a phyllosilicate selected from the group consisting of hydrophilic synthetic phyllosilicates and natural phyllosilicates intercalated with a modifier, an alkylonium ion having reactive moiety. The phyllosilicate is substantially homogeneously dispersed and/or exfoliated throughout the polymer matrix as nanosized particles and the alkylonium ion is substantially covalently linked to the matrix polymer chains. The present invention further provides a process for the preparation of polymer-phyllosilicate nanocomposite.

Description

Claims

1. A polymer-phyllosilicate nanocomposite composition comprising (a) 10-99.95% by weight of a matrix polymer and(b) 0.05-90% by weight of a phyllosilicate selected from the group consisting of hydrophilic synthetic phyllosilicates and natural phyllosilicates intercalated with a modifier, an alkylonium ion having reactive moiety.

2. The composition as claimed in claim 1, wherein the matrix polymer is selected from the group consisting of polycarbonates, polyesters and epoxy resins.

3. The composition as claimed in claim 1, wherein the matrix polymer is a polycarbonate.

4. The composition as claimed in claim 1 wherein the modifier is alkylonium ion having reactive moiety.

5. The composition as claimed in claim 1 wherein the alkylonium ion is associated with the surface of the phyllosilicate and capable of covalently link to the matrix polymer chain.

6. The composition as claimed in claim 1 wherein the phyllosilicate is homogeneously dispersed and/or exfoliated throughout the polymer matrix as nanosized particles.

7. The composition as claimed in claim 1, wherein the phyllosilicate is selected from the group consisting of natural smectite clays, synthetic smectite clays, kaolinite clays, mica, natural talcs, synthetic talcs, and combinations thereof.

8. The composition as claimed in claim 7, wherein the smectite clay is selected from the group comprising of montmorillonite, hectorite, saponite, beidellite, stevensite, nontronite, laponite, and combinations thereof.

9. The composition as claimed in claim 4, wherein the alkyl chain of alkylonium ion has at least one carbon atom.

10. The composition as claimed in claim 4, wherein the alkyl chain of alkylonium ion is having the chain length of 2 to 37 carbon atoms.

11. The composition as claimed in claim 10, wherein the alkyl chain of alkylonium ion is having chain length of 3 to 18 carbon atoms.

12. The composition as claimed in claim 11, wherein the alkyl chain of alkylonium ion is having chain length of 8 to 12 carbon atoms.

13. The composition as claimed in claim 1, wherein the alkylonium ion is selected from the group consisting of phosphonium ions, cyclic amidinium ions and ammonium ions.

14. The composition as claimed in claim 4, wherein the reactive moiety of alkylonium ion comprises at least one phenol group.

15. The composition as claimed in claim 4, wherein the reactive moiety of alkylonium ion is a bisphenol group.

16. The composition as claimed in claim 4, wherein the alkylonium ion is 2,2-bis(4-hydroxyphenyl)alkylonium salts having the formula I,

17. The composition as claimed in claim 16, wherein the alkylonium ion is 2,2-bis(4-hydroxyphenyl)alkylonium salts, wherein n=11.

18. The composition as claimed in claim 16, wherein the alkylonium ion is 2,2-bis(4-hydroxyphenyl)alkylonium salts, wherein M is triphenylphosphine.

19. The composition as claimed in claim 16, wherein the alkylonium ion is 2,2-bis(4-hydroxyphenyl)alkylonium salts, wherein M is 1,2-dimethylimidazole.

20. The composition as claimed in claim 1 comprising about 0.05 weight percent to about 40 weight percent of a phyllosilicate material intercalated with the alkylonium ion having reactive moiety (organophyllosilicate) and about 60 weight percent to about 99.95 weight percent of a matrix polymer, characterized in that the said intercalated layered silicate material is dispersed uniformly throughout the matrix polymer and/or exfoliated wherein the said alkyl onium ions are compatible with the matrix polymer or substantially covalently linked to the matrix polymer chain through the reactive moiety.

21. The composition as claimed in claim 20, wherein the matrix polymer is co-intercalated into the phyllosilicate material or the silicate layers are exfoliated.

22. The composition as claimed in claim 21, wherein the matrix polymer is co-intercalated into the layered silicate material while dispersing or exfoliating the layered material throughout the matrix polymer.

23. The composition as claimed in claim 22, wherein the matrix polymer is co-intercalated into the layered silicate material prior to dispersing or exfoliating the layered silicate material throughout the matrix polymer.

24. The composition as claimed in claim 20, wherein the matrix polymer used is a polymer or oligomer of the reaction product of bisphenols and diphenylcarbonate.

25. The composition as claimed in claim 1 comprising about 40% to about 99.95% by weight of a matrix polymer and about 0.05% to about 60% by weight of an intercalated organophyllosilicate material prepared by contacting a phyllosilicate with intercalant alkylonium ions having reactive moiety capable of compatibilize or covalently link the matrix polymer chain with a molar ratio of alkylonium ions having reactive moiety to phyllosilicate interlayer exchangeable cations of at least about 0.25:1 to achieve sorption of the alkylonium ions between adjacent spaced layers of the phyllosilicate to expand the spacing between a predominance of the adjacent phyllosilicate platelets at least about 3 Å, when measured after sorption of the alkylonium ions, and a second intercalant disposed between adjacent spaced layers of the phyllosilicate material, said second intercalant comprising a thermosetting or thermoplastic oligomer or polymer.

26. A composition as claimed in claim 25, wherein the intercalated phyllosilicate is exfoliated into a predominance of individual platelets.

27. A composition as claimed in claim 25, wherein the molar ratio of intercalant alkylonium ions having reactive moiety to phyllosilicate interlayer exchangeable cations is at least 0.5:1.

28. A composition as claimed in claim 25, wherein the molar ratio of intercalant alkylonium ions having reactive moiety:phyllosilicate interlayer exchangeable cations is at least 1:1.

29. A composition as claimed in claim 25, wherein the matrix polymer used is selected from the group consisting of epoxy, polyamide, polyvinyl alcohol, polycarbonate, polyvinylimine, polyvinylpyrrolidone, polyethylene terephthalate and polybutylene terephthalate.

30. A composition as claimed in claim 25, wherein the matrix polymer is a polycarbonate.

31. A composition as claimed in claim 1, comprising about 10% about 90% by weight of a layered material intercalated with alkylonium ions having reactive group and about 10% to about 90 by weight percent of a matrix oligomer or polymer, wherein the intercalated or the exfoliated layered silicate material is dispersed uniformly throughout the matrix polymer.

32. The composition as claimed in claim 31, wherein the matrix polymer is intercalated into the layered silicate material.

33. The composition as claimed in claim 32, wherein the matrix polymer is intercalated into the layered silicate material while dispersing or exfoliating the layered material throughout the matrix polymer.

34. The composition as claimed in claim 33, wherein the matrix polymer is intercalated into the layered silicate material prior to dispersing or exfoliating the layered silicate material throughout the matrix polymer.

35. The composition in accordance with claim 30, wherein both the matrix polymer and the polymer intercalated into and/or exfoliate the layered material are a polymer or oligomer of the reaction product of bisphenols and diphenylcarbonate.

36. The composition as claimed in claim 31, wherein the layered silicate material used is first intercalated with alkylonium ions having reactive moiety prior to intercalating the layered material with the polymer of bisphenol and diphenylcarbonate.

37. A process for the preparation of polymer-phyllosilicate nanocomposite composition comprising the steps of (a) mixing 10-99.95% by weight of a matrix polymer and 0.05-90% by weight of a phyllosilicate selected from the group consisting of hydrophilic synthetic phyllosilicates and natural phyllosilicates intercalated with a modifier and an alkylonium ion having reactive moiety,(b) intercalating a layered silicate material by contacting it with alkylonium ions having reactive group to obtain the intercalated layered material,(c) mixing the above said intercalated layered material with a melt of the matrix polymer, under stirring, to intercalate and exfoliate the said matrix polymer between adjacent platelets of the layered silicate material to obtain the desired polymer-exfoliated phyllosilicate nanocomposite composition.

38. A process as claimed in claim 37, wherein mixing of intercalate and the polymer melt is accomplished by extruding the intercalate/polymer melt mixture.

39. A process for the preparation of polymer-phyllosilicate nanocomposite comprising the steps of (a) mixing 40% to 99.95% by weight of a matrix polymer and about 0.05% to about 60% by weight of an intercalate and/or exfoliate,(b) intercalating and/or exfoliating a layered silicate material by contacting the layered silicate material with alkylonium ions having reactive moiety to exchange the alkylonium ions having reactive moiety for at least a portion of the interlayer exchangeable cations of the layered material,(c) mixing the above said intercalated layered silicate material with one or more monomer or oligomer reactants and subjecting it to conditions sufficient to polymerize the said monomer or oligomer reactants to form said matrix polymer.

40. A process for the preparation of polymer-phyllosilicate nanocomposite comprising the steps of (a) contacting a layered silicate material with alkylonium ions having reactive moiety to intercalate the alkylonium ions having reactive moiety between the adjacent layers of said layered silicate material,(b) increasing the spacing between adjacent layers of the layered material at least 3 Å, simultaneously or subsequently contacting the above said intercalated layered silicate material with a solution or dispersion of an oligomer or polymer to intercalate the oligomer or polymer between the adjacent layers of the said layered silicate material to expand the spacing between the adjacent layers at least an additional 3 Å, and(c) mixing the layered silicate material, having said alkylonium ions having reactive moiety and said oligomer or polymer intercalated between adjacent layers and/or exfoliated, with an oligomer or polymer matrix material.

41. The process of claim 40, wherein the oligomer or polymer intercalated between adjacent layers of said layered silicate material or exfoliated is the same oligomer or polymer matrix material mixed with said intercalate.

42. A process as claimed in claim 40, wherein the alkylonium ions intercalated phyllosilicate is obtained by exchanging the exchangeable cations in the phyllosilicate with 2,2-bis(4-hydroxyphenyl)alkylonium salt having formula 1,

43. A process as claimed in claim 42, wherein the exchanging is carried out by first dispersing the phyllosilicate in a polar solvent and then adding the alkylonium salt and stirring it together at a temperatures in the range of 10° C. to 100° C. for a period of 0.5 h to 24 h and then filtering the organophyllosilicate cake, followed by washing it with a solvent to remove excess salt and the metallic salt which has come out of the adjacent sheets of the phyllosilicate, and drying it under vacuum in a freeze drier to obtain the desired fine particles of organophyllosilicate.

44. A polymer-phyllosilicate nanocomposite composition and a process for the preparation thereof substantially as herein described with reference to the examples.