Non-aqueous dispersants

1. A non-aqueous dispersant (NAD) comprising a condensate formed by the grafting of an adduct of a hydrophobic stabilising entity (HSE) selected from the group consisting of polyhydroxystearic acid (PHSA), polyisobutylene succinic anhydride (PIBSA), and polycaprolactone with a linker substrate selected from the group consisting of a glycol, an alkanolamine, an ether amine, and an ethylene amine onto a co-polymer, wherein the co-polymer comprises a styrene-maleic anhydride (SMA) co-polymer.

2. The non-aqueous dispersant according to claim 1 , wherein the HSE is PHSA having a molecular weight (Mn) of greater than 1000 Da.

3. The non-aqueous dispersant according to claim 1 , wherein the condensate is anionic and/or acidic.

4. The non-aqueous dispersant according to claim 1 , wherein the SMA co-polymer has a styrene:maleic anhydride stoichiometric ratio range of from 1:1 to 3:1.

5. The non-aqueous dispersant according to claim 1 , wherein the condensate is formed by the reaction of the SMA co-polymer and the adduct of the HSE in a stoichiometric ratio range of from 1:2 to 8:1 and in a molecular weight (Mn) range of 1,000 to 40,000 Da.

6. The non-aqueous dispersant according to claim 1 , wherein the linker substrate is selected from the group consisting of a polyoxyalkylene, monoethylene glycol (MEG), diethylene glycol (DEG), triethylene glycol (TEG), polyethylene glycol (PEG), a polyoxyalkylene, wherein in the formula HO[-CH 2 -CH-R-O-] n -H, (R=H or CH 3 ) and n=1-100, a glycolamine, diglycolamine (DGA), triglycolamine (TGA), a polyetheramine, 4-hydroxyaniline, monoethanolamine (MEA), monoisopropanolamine (MIPA), ethylenediamine (EDA), triethylenetetramine (TETA), and tetraethylenepentamine (TEPA).

7. The non-aqueous dispersant according to claim 1 , wherein the linker substrate comprises a polyetheramine selected from the group consisting of an amine terminated polyoxypropylene, and a diamine with a predominantly polyethylene glycol backbone having a terminal amine.

8. The non-aqueous dispersant according to claim 1 , wherein the PHSA is modified by the following reaction with a reactant selected from the group consisting of N-hydroxyethyl(meth)acrylamide (HEAA), N-hydroxyethyl methacrylamide (HEMAm), 2-hydroxyethyl acrylate (HEA), 2-hydroxyethyl methacrylate (HEMA), 4-vinylaniline, 4-vinylphenol, an allylalcohol, and an allylamine; and

wherein the adduct is a macromonomer having an ethylenically unsaturated terminus.

9. The non-aqueous dispersant according to claim 1 , wherein the linker substrate is monoethanolamine and wherein the adduct is PHSA-monoethanolamide.

10. The non-aqueous dispersant according to claim 9 , wherein the PHSA used in the reaction with monoethanolamine to form the PHSA-monoethanolamide adduct has a molecular weight of greater than 1000 g/mol as determined by an acid value of about 25 to 50 mg KOH/g.

11. The non-aqueous dispersant according to claim 1 , wherein the condensate further comprises a sulphonic acid functionality.

12. The non-aqueous dispersant according to claim 11 , wherein the sulphonic acid functionality is selected from the group consisting of taurine, isethionic acid, 4-aminobenzenesulphonic acid, 4-hydroxybenzenesulphonic acid 1-hydroxy-2-propanesulfonic acid, and their respective salts.

13. The non-aqueous dispersant according to claim 12 , wherein the sulphonic acid-functionality is taurine or its salt and wherein a SMA:PHSA-monoethanolamide:taurine co-polymer is formed.

14. The non-aqueous dispersant according to claim 13 , wherein the stoichiometric ratio of the SMA:PHSA-monoethanolamide:taurine co-polymer is 1:0.9:0.1.

15. The non-aqueous dispersant according to claim 13 , wherein the stoichiometric ratio of the SMA:PHSA-monoethanolamide:taurine co-polymer is 0.92:1.00:0.46.

16. The non-aqueous dispersant according to claim 14 , wherein the reaction mixture is neutralised with an alkaline/basic reagent.

17. The non-aqueous dispersant according to claim 16 , wherein the alkaline/basic reagent is NaOH.