Polymer composites

Claim 2

A polymer matrix having grown therein in vitro and in situ, non-centrosymmetric crystals of organic or inorganic compounds.

Claim 3

A polymer matrix according to claim 1 wherein the non-centrosymmetric crystals are oriented within the polymer matrix.

Claim 4

A polymer matrix according to claims 1 or 2 wherein the polymer is selected from polystyrene, polyethylene, polypropylene, polymethylmethacrylate, ethylene-ethylacrylate copolymer, polyvinylchloride, polyvinylidene fluoride and a polyoxyalkylene oxide.

Claim 5

A polymer matrix according to any one of the preceding claims wherein said matrix is in film form.

Claim 6

A polymer matrix according to any one of the preceding claims wherein the compounds capable of forming non-centrosymmetric crystals form such crystals under ambient conditions.

Claim 7

A polymer matrix according to any one of the preceding claims wherein the organic compound capable of forming non-centrosymmetric crystals is selected from 3-nitroaniline, 3-methyl-4-nitropyridine-­1-oxide, 2-methyl-4-nitroaniline, urea and 2-4-dinitroaniline.

Claim 8

A polymer matrix according to any one of the preceding claims 1-5 wherein the inorganic compound capable of forming non-centrosymmetric crystals is selected from potassium dihydrogen orthophosphate, ammonium dihydrogen orthophosphate, lithium niobate, barium sodium niobate, lithium iodate and silicon dioxide.

Claim 9

A process for producing a polymer matrix having grown therein in situ oriented, non-centrosymmetric crystals of organic or inorganic compounds, said process comprising dissolving the compound to be crystallised and the matrix polymer in common solvent, then casting the solution into the desired shape on a substrate thereby allowing the compound to crystallise in situ in the matrix upon gradual evaporation of the solvent and finally subjecting the composite so formed to orientation.

Claim 10

A process for producing a polymer matrix having grown therein in situ oriented, non-centrosymmetric crystals of organic or inorganic compounds, said process comprising dissolving the compound to be crystallised and the matrix polymer in common solvent, then casting the solution into the desired shape on a substrate thereby allowing the compound to crystallise in situ in the matrix upon gradual evaporation of the solvent and finally subjecting the composite so formed to orientation.

Claim 11

A process for producing a polymer matrix having grown therein in situ oriented, non-centrosymmetric crystals of organic or inorganic compounds, said process comprising dissolving a first compound and the matrix polymer in a common solvent, casting the solution into the desired shape on a substrate thereby allowing the first compound to crystallise in situ in the matrix, dipping the shape so formed into a solution of a second compound, which is also capable of forming non-centrosymmetric crystals thereby allowing crystals of said second compound to be formed in situ in the matrix polymer either by a reaction between the first and second compounds or by the displacement of the first compound by the second compound and finally subjecting the composite so formed to orientation.

Claim 12

A process for producing a polymer matrix having grown therein in situ oriented, non-centrosymmetric crystals of organic or inorganic compounds, said process comprising dissolving a first compound and the matrix polymer in a common solvent, casting the solution into the desired shape on a substrate thereby allowing the first compound to crystallise in situ in the matrix, dipping the shape so formed into a solution of a second compound, which is also capable of forming non-centrosymmetric crystals thereby allowing crystals of said second compound to be formed in situ in the matrix polymer either by a reaction between the first and second compounds or by the displacement of the first compound by the second compound and finally subjecting the composite so formed to orientation.

Claim 13

A process according to claim 8 or 9 wherein the crystals of the organic or inorganic compounds formed in situ are oriented in such a manner that all the crystals are substantially in parallel alignment.

Claim 14

A process according to claim 10 wherein the orientation of the crystals is achieved by (a) stretching the composite during cooling after formation thereof, or (b) cold-drawing the formed composite, (c) subjecting the formed composite to an appropriate electrical field optionally accompanied by or preceded by drawing, (d) crystallisation of the composite in a stationary or mobile temperature gradient, or (e) swelling oriented matrix polymers with a solution of the compound which is then allowed to crystallise.