File Name: chemistry of lipids fats and oils soaps and detergents .zip
Soap is a salt of a fatty acid  used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing , bathing , and other types of housekeeping. In industrial settings, soaps are used as thickeners , components of some lubricants , and precursors to catalysts.
26.2: Saponification of Fats and Oils; Soaps and Detergents
Carboxylic acids and salts having alkyl chains longer than eight carbons exhibit unusual behavior in water due to the presence of both hydrophilic CO 2 and hydrophobic alkyl regions in the same molecule. Such molecules are termed amphiphilic Gk. Fatty acids made up of ten or more carbon atoms are nearly insoluble in water, and because of their lower density, float on the surface when mixed with water. Unlike paraffin or other alkanes, which tend to puddle on the waters surface, these fatty acids spread evenly over an extended water surface, eventually forming a monomolecular layer in which the polar carboxyl groups are hydrogen bonded at the water interface, and the hydrocarbon chains are aligned together away from the water. This behavior is illustrated in the diagram on the right.
Saponification is the process in which triglycerides are combined with a strong base to form fatty acid metal salts during the soap-making process. The distribution of unsaturated and saturated fatty acid determines the hardness, aroma, cleansing, lather, and moisturizing abilities of soaps. Plant extracts, such as rosemary, vegetable, and essential oils are frequently added to soaps to enhance quality and sensory appeal. Three natural soaps were formulated using cold saponification to produce a base or control bar BB , hibiscus rosehip bar H , and a forest grove bar FG. Rosemary extract R or essential oil A blends were added as additives to each formulation prior to curing to evaluate the effects of natural plant additives on the lipid composition and sensory characteristics of these natural herbal soaps. Principal component analysis PCA analyses showed the unsaponifiable fatty acids were different in the hibiscus bar compared to the other bars.
Soap and detergent
The lipids are a large and diverse group of naturally occurring organic compounds that are related by their solubility in nonpolar organic solvents e. There is great structural variety among the lipids, as will be demonstrated in the following sections. You may click on a topic listed below, or proceed page by page. The common feature of these lipids is that they are all esters of moderate to long chain fatty acids. Acid or base-catalyzed hydrolysis yields the component fatty acid, some examples of which are given in the following table, together with the alcohol component of the lipid.
Saponification value or saponification number SV or SN represents the number of milligrams of potassium hydroxide KOH required to saponify one gram of fat under the conditions specified. The higher the saponification value, the lower the fatty acids average length, the lighter the mean molecular weight of triglycerides and vice-versa. Practically, fats or oils with high saponification value such as coconut and palm oil are more suitable for soap making. To determine saponification value, the sample is hot-saponified with an excess of alkali usually potassium hydroxide dissolved in ethanol , in standard conditions, generally for half an hour under reflux. Handmade soap makers who aim for bar soap use sodium hydroxide NaOH , commonly known as lye , rather than KOH caustic potash which produces soft paste, gel or liquid soaps.
Healthy Cleaning This section is intended to be a valuable information resource about cleaning products for consumers, educators, students, media, government officials, businesses and others. Water, the liquid commonly used for cleaning, has a property called surface tension.
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