Polyunsaturated rubbers

The oxidation of a polymer is dependent both on its chemical structure and on its morphology [4, 9]. In general the polyunsaturated rubbers are very susceptible to oxidation due to the presence of the olefinic double bond in the polymer back-bone and the absence of crystallinity. They are autoxidized by the well-known radical chain reaction summarized in reaction (1.1) [12] ... 

The rate of peroxidation of hydrocarbon polymers in the absence of added initiators increases by two orders of magnitude, from the relatively stable unbranched polyethylenes through branched polypropylene to the polyunsaturated rubbers [11] ... 

Stabilization of Elastomers. Polyunsaturated elastomers are sensitive to oxidation. Stabilizers are added to the elastomers prior to vulcanization to protect the rubber during drying and storage. Nonstaining antioxidants such as butylated hydroxytoluene (1),... 

One of our major areas of development was the synthesis and study of the chromatographic (8-10), spectroscopic (11-14), and spectrometric properties of a large number of heteroaromatic fatty acid derivatives (each containing either a furan, pyrrole, thiophene, selenophene, or tellurophene nucleus). These fatty acid derivatives were obtained by total synthesis or by partial synthesis from polyunsaturated unsaturated fatty acids (12,13,15-18) and unsaturated hydroxylated fatty acids, such as ricinoleic acid (from castor oil) (19-24). In this range of heteroaromatic fatty acid derivatives, only fatty acids containing a furan nucleus are found in nature (lipid extracts of the pike and salmon and from the latex of the rubber plant) (25-29). A typical method for the preparation of a disub-... 

Natural rubber consists of polyterpenes. The gross formula of this basic elastomer in natural rubber is (CsHgln. The module is isoprene (the base of all terpenoides). It is a polyunsaturated polymer with a structure as shown in... 

Elastomers. Polyunsaturated elastomers are sensitive to oxidation. Stabilizers are added to the elastomers prior to vulcanization to protect the rubber during drying and storage. Nonstaining antioxidants such as buty-lated hydroxytoluene (1), 2,4-bis(octylthiomethyl)-6-methylphenol [110553-27-0], 4,4 -bis(a, a -dimethylbenzyl)diphenylamine (14), or aphosphite such as tris(nonyl-phenyl)phosphite (24) may be used in concentrations ranging from 0.01 to 0.5%. 

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