Factice

Sulfurized olefins (S2CI2 plus isobutene) are further reacted with S and Na2S to give products useful as extreme pressure lubricant additives (144,145). The reaction of unsaturated natural oils with sulfur monochloride gives resinous products known as Factice, which are useful as art-gum erasers and mbber additives (146,147). The addition reaction of sulfur monochloride with unsaturated polymers, eg, natural mbber, produces cross-links and thus serves as a means for vulcanizing mbber at moderate temperatures. The photochemical cross-linking of polyethylene has also been reported (148). 

Natural rubber displays the phenomenon known as natural tack. When two clean surfaces of masticated rubber (rubber whose molecular weight has been reduced by mechanical shearing) are brought into contact the two surfaces become strongly attached to each other. This is a consequence of interpenetration of molecular ends followed by crystallisation. Amorphous rubbers such as SBR do not exhibit such tack and it is necessary to add tackifiers such as rosin derivatives and polyterpenes. Several other miscellaneous materials such as factice, pine tar, coumarone-indene resins (see Chapter 17) and bitumens (see Chapter 30) are also used as processing aids. 

Faktis, n. factice (rubber substitute), faktischt a. real, actual, de facto. 

Riibol, n. rape oil, rapeseed oil, colza oil -faktis, n. rape oil factice. -kuchen, m. rape-seed cake. 

Similarly, in the case of a cup type mount, an initial attempt to restrict resonance amplification featured the use of white factice in a NR formulation. However, the successful formulation was a blend of predominantly bromobutyl with NR, as shown in Table 6. 

Nag and Haidar reported the purification of vegetable oil extracted from the seeds of Pongamia glabra and its ability to substitute commercially available factices [33]. Factices are usually used for mastication of NR during production of tubing, automobile parts, and window seals. The authors reported improvement in thermal stability of the NR vulcanizate after the factice was added. 

A compounding ingredient with the main functions of a processing aid or extender. Dark factice (sulphur factice) is produced by heating certain unsaturated oils (principally rape seed oil) with sulphur. White factice (sulphur chloride factice) is prepared by treating rape seed oil with sulphur monochloride at normal temperatures. Factice is still sometimes referred to as mbber substitute or simply sub , but these terms are not recommended. 

A basic substance used particularly in compounds containing large quantities of white factice to offset the retarding effect of the factice. Also used to prepare emulsifying agents in latex compounding. 

Also termed sulphur chloride factice or cold factice. That type of factice prepared by treating unsaturated oils, such as rape oil or castor oil, with sulphur monochloride. Since the reaction is exothermic care must be taken to keep the temperature as low as possible. See Factice. White Metal... 

The oils from which factices are manufactured are unsaturated vegetable and animal oils, which react with sulphur. Fatty oils with iodine number greater than 80 (iodine number is defined as the number of grammes of iodine absorbed by 100 g of fat/oil) are generally used, i.e., oils with three or more double bonds per triglyceride molecule. Rapeseed oil is the most common oil used for general purpose grades and castor oil is used for oil resistant factice. Other oils are used in preference by other countries due to local availability and cost. 

Factice has a number of uses in rubber compounds where it can stabilise dimensions of products such as hoses and tubing during the early stages of heating of the vulcanisation cycle. It imparts stability to extruded products, a silkiness to calendered products, gives good dimensional stability and overcomes many of the problems of crows feet and blistering. 

The addition level for the different applications varies from 5-10 phr for moulded articles to 15-30 phr for extrusions. Roller coverings, dependant upon hardness, are often made using factices to facilitate grinding operations. Special products such as erasers use factice, usually white factice, at levels between 200-400 phr. 

In general terms, factice gives benefits to rubber processing without causing any undue effects on physical properties. 

Clear unsaturated oils are vulcanised at room temperature with sulphur monochloride to give a white, friable solid which is nonstaining and suitable for use in coloured compounds. Crosslinking using sulphur monochloride produces a white factice, but care had to be taken in its use, for if not used when fresh it develops a high level of acidity which affects compound cures severely. The acidity can be removed by steaming the factice just prior to use. Modem white factices contain a small addition of alkali to counteract any developed acidity. 

Alternative crosslinking systems used to produce the wide variety of factices offered include ... 

Very high oil loadings of aromatic oils can be compatible with some grades of CR. However, the level of the oil s aromaticity must be carefully considered, for although compatible with loadings of up to about 100 phr of oil, stickiness of the vulcanised surface can result in highly filler loaded compounds. This has been found to be overcome by the use of oils with lower compatibility, i.e., less aromaticity, and by the incorporation of small amounts of factice or SBR to assist... 

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