Audited Supplier
Stearic acid is one of the most common fatty acids. It exists as a glycerol ester in most animal and plant fats (Beare-Rogers, Dieffenbacher, & Holm, 2001). Stearic acid is more abundant in animal fat (up to 30%) than vegetable fat (typically <5%). The important exceptions are cocoa butter and shea butter, in which the stearic acid content (as a triglyceride) is 28-45%. Unlike the other long-chain saturated fatty acids, stearic acid has no effect on lipoprotein cholesterol concentrations in men or women (Yu, Derr, Etherton, & Kris-Etherton, 1995). Results from the study by Kelly et al. (2001) indicate that stearic acid (19 g/day) in the diet has favorable effects on thrombogenic and atherogenic risk factors in males; the authors recommend that the food industry consider enriching foods with stearic acid instead of palmitic acid and trans fatty acids. Thus, stearic acid is nontoxic and biocompatible with the human body. With a polar head group that can bind with metal cations and a nonpolar chain that confers solubility in organic solvents, stearic acid is commonly used in the production of detergents, soaps, and cosmetics, such as shampoos and shaving cream products.
Stearic acid treatment involves the reaction of the hydroxyl group of the fiber with the stearic acid group. It is done to make the fiber surface hydrophobic in order to yield better compatibility. This kind of treatment does not significantly affect the fiber strength.
Stearic acid (CH3(CH2)16COOH) in ethyl alcohol solution was investigated in fiber treatment and Zafeiropoulos. It was reported that this treatment removed non-crystalline constituents of the fibers, thus altering the fiber surface topography. Zafeiropoulos also observed that treated flax fibers were more crystalline than the untreated ones and stearation decreased the fiber surface free energy.
Stearic acid is a saturated fatty acid that can deposit on the surface in special conditions. This acid is insoluble in water and soluble in ethanol. The copper substrate should be cleaned, pickled, and soaked in 10% volume HNO3 for oxide elimination. The clean sample should be soaked in ethanolic stearic acid solution (0.01 M) and 30 V DC should be applied. The anode and cathode should be made of copper. Studying the X-ray powder diffractometer (XRD) peaks proves the existence of copper stearate components resulting from the reaction of stearic acid with copper. These components provide the necessary roughness and low energy of hydrophobia so the contact angle arrives at 153° and so the hysteresis of the contact angle decreases. Other researchers created a self-assembled layer on porous alumina using stearic acid. This method was performed on anodized aluminum in 0.01 volume of stearic acid solution in ethanol for 30 min without applying any potential and superhydrophobia was achieved.
