Composite material and its method of production

1 . A composite material obtained from a process comprising a step of polymerizing

(i) a functionalized carbon nanoparticle that is graphene oxide functionalized with primary amino groups,

(ii) a polyol selected from the group consisting of a polycarbonate diol and a polycaprolactone diol,

(iii) a methylenebisphenyl isocyanate compound comprising at least two isocyanate groups, and

(iv) optionally a chain extending compound comprising at least two primary amine groups,

wherein the process comprises preparing a mixture of (i) and (ii), heating the mixture to clarify the mixture, and thereafter adding (iii) to the clarified mixture and polymerizing (i), (ii) and (iii).

2 . The composite material according to claim 1 , wherein the chain extending compound is an aliphatic amine.

3 . The composite material according to claim 1 , wherein the composite material comprises a carbon nanoparticle moiety obtained from the functionalized carbon nanoparticle (i) and a polyol moiety obtained from the polyol (ii), wherein the carbon nanoparticle moiety is covalently bonded to the polyol moiety by a urethane linkage and a urea linkage or by a urethane linkage and an amide linkage.

4 . The composite material according to claim 1 , comprising a second step of adding a monoamine after completion of the step of polymerizing.

5 . The composite material according to claim 1 , wherein the primary amino groups are present on both the edge and the plane of the graphene oxide.

6 . The composite material according to claim 1 , wherein the functionalized carbon nanoparticle is made by a process comprising the steps of converting carboxylic acid moieties present on a graphene oxide nanoparticle into acyl chloride groups, reacting the acyl chloride groups with ammonium hydroxide to convert them into amido groups, and reducing the amido groups to primary amino groups.

7 . A composite material which is a copolymer of (i) a functionalized carbon nanoparticle which is graphene oxide functionalized with primary amine groups, (ii) a polyol selected from the group consisting of a polycarbonate diol and a polycaprolactone diol, (iii) a methylenebisphenyl isocyanate compound comprising at least two isocyanate groups, optionally (iv) a chain extending compound comprising at least two primary amine groups, and optionally (v) a monoamine,

wherein the functionalized carbon nanoparticle and the polyol are covalently bonded by a urethane linkage and a urea linkage or by a urethane linkage and an amide linkage,

wherein the copolymer is prepared by preparing a mixture of (i) and (ii), heating the mixture to clarify the mixture, and thereafter adding (iii) to the clarified mixture and polymerizing (i), (ii) and (iii).

8 . The composite material according to claim 7 , wherein the chain extending compound is selected from the group consisting of an aliphatic amine, an aliphatic carboxylic acid, an aliphatic alcohol, a functionalized silica nanoparticle, an amino acid, a peptide, and a polypeptide.

9 . The composite material according to claim 7 , wherein the primary amino groups and, where present, primary alcoholic groups, are present on both the edge and the plane of the graphene sheet.

10 . The composite material according to claim 7 , wherein the functionalized carbon nanoparticle is made by a process comprising the steps of converting carboxylic acid moieties present on a carbon nanoparticle into acyl chloride groups, reacting the acyl chloride groups with ammonium hydroxide to convert them into amido groups, and reducing the amido groups to primary amino groups.

11 . A molded article comprising the composite material of claim 1 .

12 . A molded article comprising the composite material of claim 7 .

13 . The composite material of claim 1 , wherein the mixture of (i) and (ii) is heated to a temperature of at least 80° C.

14 . The composite material of claim 7 , wherein the mixture of (i) and (ii) is heated to a temperature of at least 80° C.