Alkanolamine Condensates, Alkanolamides

Alkanolamine Condensates, Alkanolamides Mainly of diethanolamine or monoisopropanolamine. Good stability to hydrolysis by hot alkali, poor-fair stability to hot acids. 

1 1 Alkanolamine-Fatty Acid Condensates Made by reaction of methyl or triglyceride ester of fatty acid with equimolar amount of alkanolamine (about 90% alkanolamide content in product from methyl ester, 80% from triglyceride). Mainly based on coconut or purified coconut (lauric) esters. 

Diethanolamides are insoluble but dispersible in water, soluble in organic solvents except some aliphatic hydrocarbons. Compatible with both anionics and cationics over wide pH range. Poor wetting and detergent properties, but synergistic to surfactants showing these properties. Show corrosion-inhibiting properties for steel. Easily prepared. 

2 1 Alkanolamine-Fatty Acid Condensates Made by reaction of 2 mol alkanolamine with 1 mol free fatty acid. Contains about 60-70% alkanolamide, 25-30% alkanolamine, 3-5% fatty acid (as soap of alkanolamine). Mainly based on coconut fatty acid. 

Polyoxyethylenation of the hydroxyl groups with a few oxyethylene units increases solubility in water without significant change in surface properties, but resulting products are liquid and nonvolatile with steam. 

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NON-IONIC SURFACTANTS Polyoxyethylenated alkylphenols, alkylphenol ethoxylates Polyoxyethylenated straight- chain alcohols, alcohol ethoxylates Polyoxyethylenated polyoxypropylene glycols Polyoxyethylenated mercaptans Long-chain carboxylic acid esters Alkanolamine condensates, alkanolamides Tertiary acetylenic glycols Polyoxyethylenated silicones N-alkylpyrrolidones Alkylpolyglycosides... 

Hlkanolamides. The fatty acid alkanolamides are used widely ia shampoo formulations as viscosity and lather builders. They are formed by the condensation of a fatty acid with a primary or secondary alkanolamine. The early amides were compositions of 2 1 alkanolamine to fatty acid. Available technology allows the formation of amides with a 1 1 ratio of these additives. These amides are classified as superamide types. The typical amide used ia shampoo preparations usually contains the mono- or diethanolamine adduct, eg, lauric diethanolamide [120-40-1] (see Amides, fatty acid). 

Mining. Numerous patents have advocated the use of alkanolamines in mining appHcations. Triethanolarnine has been used as a depressent in the flotation of copper (164), in the electrotwinning of gold (165), and as an aid in the froth flotation of nickel ores. Phosphate ore flotation has been improved through the use of a fatty acid condensate with ethanolamine (166). Beneficiation of tin ore has been accompHshed using fatty acid alkanolamides (167). 

Alkanolamides are produced by condensation of fatty esters or acids with an alkanolamine. The monoalkanolamides account for 30% of market while diethanolamides account for the bulk of the rest with the balance being made up of a few specialised materials. 

Early experiments in the preparation of alkanolamides were begun by Kritchevs-ky (24, 25). It involves condensation reactions of fatty acids, triglycerides, esters, amides, anhydrides, and halides with an alkanolamine. The reaction was carried out at 100-300°C at atmospheric pressure. An important improvement was made by... 

Alkanolamides are condensation products of fatty acids with primary or secondary alkanolamines (Feairheller et al., 1994 Kopylov et al., 1980 Maltby Read, 2000). These products are nonionic surface-active agents and find application in a multitude of uses including dry-cleaning soaps, fuel-oil additives, rust inhibitors, textile scouring, and dye-leveling agents. 

The alkanolamides are condensates of fatty acids and alkanolamines they are nonionic surfactants. Based on different alkanolamines such as monoethanolamine (MEA), diethanolamines (DEA), and monoisopropylamine (MIPA), and derivatives from oils and fats, they are hybrids from petrochemistry and from renewable oleochemistry. 

Classically, alkanolamides are condensation products of alkanolamines (mainly mono-, and diethanolamine and mono-isopropanolamine) with fatty acids, methyl esters or triglycerides (natural oils). 

Early experiments in the preparation of alkanolamides were begun by Kritchevsky (20, 21). It involves condensation reactions of fatty acids, triglycerides, esters, amides, anhydrides, and halides with an alkanolamine. The reaction was carried out at 100-300°C at atmospheric pressure. An important improvement was made by Meade (22), who made use of an alkali metal alkoxide as a catalyst at 100°C at atmospheric and slightly above atmospheric pressure. Fmther refinement was made by Tesoro (23), who conducted the reaction at 55-75°C and a vacuum of 4—8 kPa. Schurman (24) patented a continuous process for making alkanolamide, which makes use of a thin film reactor. It is claimed the short contact time in the reactor produces a high-purity alkanolamide (25). 

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