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US 2019/0367686 A1Published application
Stable waterborne polyurethane/clay nanocomposite
AssigneeKing Fahd University of Petroleum and Minerals
InventorsMohammad Mizanur Rahman, Ahmad Sorour
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Abstract
A method of preparing stable waterborne polyurethane nanocomposite with a long shelf-life time is described. The stability of the nanocomposite is achieved by effective mechanical and sonication mixing of diisocynate and clay. Also, the stability is achieved through optimization of the amount of clay and carboxylic acid with hydroxyl functionality.
Claims20
1:
- A method for preparing a waterborne nanocomposite dispersion, comprising:
- mixing a diisocyanate and an organoclay to form a first mixture;
- mixing a polyol, a carboxylic acid having hydroxyl functionality and a solvent to form a second mixture;
- mixing the first mixture with the second mixture and heating at a temperature in a range of 40-90° C. for 2-6 hours to form a prepolymer with a carboxylic acid group;
- mixing a base with the prepolymer with a carboxylic acid group to form a prepolymer with a carboxylic acid salt;
- mixing water with the prepolymer with a carboxylic acid salt to form a dispersion;
- and
- reacting the dispersion with a diamine as a chain extender to form the waterborne nanocomposite dispersion.
5 more elements
2:
- The method of claim 1, further comprising sonicating the first mixture for 10-30 minutes prior to the reacting.
3:
- The method of claim 1, wherein the organoclay is modified with methyl, tallow, bis-2-hydroxyethyl quaternary ammonium chloride.
4:
- The method of claim 3, wherein the tallow is reduced or unreduced.
5:
- The method of claim 1, wherein the diisocyanate is selected from the group consisting of isophorone diisocyanate, methylene bis-phenyl isocyanate, hexamethylene diisocyanate, and 4,4′-dicyclohexylmethane diisocyanate.
6:
- The method of claim 1, wherein the polyol is selected from the group consisting of poly(tetraethyleneoxide) glycol, polyethylene glycol, polybutylene glycol, and polypropylene glycol.
7:
- The method of claim 1, wherein the carboxylic acid contains at least two hydroxyl groups and is selected from the group consisting of dimethylol propionic acid, 2,2-bis(hydroxymetyl)butyric acid, and 3-hydroxy-2,2bis(hydroxymethl)propionic acid.
8:
- The method of claim 1, wherein the solvent is 1-methyl-2-pyrrolidone or dimethylformamide.
9:
- A waterborne polyurethane/clay nanocomposite dispersion produced by the method of claim 1.
10:
- A waterborne polyurethane/clay nanocomposite dispersion produced by the method of claim 4.
11:
- A waterborne nanocomposite dispersion, comprising:
- water in an amount of 30-90 wt. % relative to a total weight of the dispersion;
- and
- a polyurethane/clay nanocomposite with a mean particle size of 40-80 nm dispersed in the water, wherein the nanocomposite comprises:
- a polyurethane polymer comprising reacted units of a diisocyanate, a polyol, a carboxylic acid salt having a hydroxyl functionality, and a diamine;
- wherein a molar ratio of a total number of mols of the polyol, the carboxylic acid salt having a hydroxyl functionality and the diamine to a number of mols of the diisocyanate is in a range of 0.9-1.1;
- and
- wherein a molar content of the carboxylic acid salt is in a range of 10-30 mol % relative to the polyurethane polymer;
- and
- an organoclay in an amount of 0.1-5.0 wt. % relative to a total weight of the nanocomposite
7 more elements
12:
- The waterborne nanocomposite dispersion of claim 11, wherein the organoclay is modified with reduced or unreduced methyl, tallow, bis-2-hydroxyethyl quaternary ammonium chloride.
13:
- The waterborne nanocomposite dispersion of claim 11, wherein the diisocyanate is selected from the group consisting of isophorone diisocyanate, methylene bis-phenyl isocyanate, hexamethylene diisocyanate, and 4,4′-dicyclohexylmethane diisocyanate.
14:
- The waterborne nanocomposite dispersion of claim 11, wherein the polyol is selected from the group consisting of poly(tetraethyleneoxide) glycol, polyethylene glycol, butylene glycol, and polypropylene glycol.
15:
- The waterborne nanocomposite dispersion of claim 12, wherein the carboxylic acid contains at least two hydroxyl groups.
16:
- The waterborne nanocomposite dispersion of claim 11, wherein the carboxylic acid is selected from the group consisting of dimethylol propionic acid, 2,2-bis(hydroxymetyl)butyric acid, and 3-hydroxy-2,2bis(hydroxymethl)propionic acid.
17:
- The waterborne nanocomposite dispersion of claim 11 contains about 2.5% by weight of clay and about 23.6 mol % dimethylol propionic acid.
18:
- The waterborne nanocomposite dispersion of claim 11, which has a zeta potential of −0.50 to −0.2 mV.
19:
- The waterborne nanocomposite dispersion of claim 11, which has a viscosity of 80 cP to 460 cP.
20:
- The waterborne nanocomposite dispersion of claim 1, which has a shelf time of up to 9-24 months.