Polymers from Unsaturated Natural Oils

Low-molecular-weight products are produced from unsaturated natural oils by cross-linking reactions, and of these, linoxyn and factice deserves special mention. 

Linoxyn is obtained from linseed oil, which is a mixture of unsaturated fatty acids with small amounts of saturated acids. The composition of linseed oil varies according to type, climate, soil composition, fertilizer, etc. A typical composition contains  

51 % linolenic acid CH3CH2CH=CHCH2CH=CHCH2CH=CH(CH2)7COOH 

Linseed oil is prepolymerized at 60°C under oxygen. The resulting linoxyn is then homogenized at 150 C to a tough gel with colophonium or copal resin. This gives linoleum cement, which is mixed with fillers and dyes, rolled onto a jute backing, and hardened to linoleum. 

Factice is produced from fatty oils such as linseed oil, castor oil, soybean oil, or rape seed oil. To obtain brown factice, the oil is heated with sulfur to 130-160°C for 6-8 h. This vulcanization gives a soft, crumbly, elastic product with 5-20 % sulfur. White factice is obtained by vulcanization of the oil with S2CI2 at room temperature. It contains 15-20% sulfur and is not elastic. Both types of factice are used as cheap bulking materials in rubber articles, and improve the calendering processing of natural rubber. 

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An oil derived fatty acid is chemically combined into a polymer structure. All natural fats are triglycerides [ 1 mole of glycerine -f 2 molecules of fatty acid (saturated)]. Oils are formed from unsaturated fatty acids. All saturated fatty acids contain double bonds. 

At ambient temperatures (0 to 40°C), TPOs have quite rubber-Uke properties. As the temperature is raised, however, these properties deteriorate quite sharply. On the other hand, the absence of unsaturation in the polymer backbones of both PP and EPDM makes these polymers and the TPOs derived from them very resistant to degradation by oxidation or ozone attack. The nonpolar nature of EPDM/PP TPOs makes them highly resistant to water, aqueous solutions, and other polar fluids such as alcohols and glycols, but they swell extensively with loss of properties when exposed to halocarbons and oils and fuels. 

Antioxidant an-te- ak-so-dont, ian- tI- (1926) n. A substance that slows down the oxidation of oils, fats, etc., and thus helps to check deterioration antioxidants are added commercially to foods, soaps, etc. Although the term technically applies to molecules reacting with oxygen, it is often applied to molecules that protect from any free radical molecule with unpaired electrons. Chemistry encyclopedia, www. ChemistryAbout.com. A substance incorporated in a material to inhibit oxidation at normal or elevated temperatures. Antioxidants are used mainly with natural and synthetic rubbers, petroleum-based resins, and other such polymers that oxidize readily due to structural unsaturation. However, some thermoplastics, namely polypropylene, ABS, rubber-modified polystyrene, acrylic and vinyl resins, also require protection by antioxidants for some uses. There are two main classes (1) Those inhibit oxidation by reacting with chain-propagating radicals, such as hindered phenols that intercept free radicals. These are called primary antioxidants or free-radical scavengers. (2) Those decompose peroxide into non-radical and stable products examples are phosphates and various sulfur compounds, e.g., esters of thiodipropionic acid. These are referred... 

MA adducts of natural unsaturated acids and esters, such as linoleic and abietic, have found use in modified drying oil especially in paint, varnish, and printing industries due to their rapid drying characteristics.Monomers and polymers made from terpenes and MA have also been used. Esters of DA adducts have also been utilized as plasticizers. An enormous amount of patent activity which can hardly be touched in such a work attests to the usefulness of the DA reaction of MA in commercial products. 

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