Factice is vulcanized unsaturated vegetable or animal oil, used as a processing aid and property modifier in rubber.
Longer chain fatty-acid containing oils such as rapeseed or meadowfoam produce a harder, more desirable factice. Soybean oil produces lower quality factice, though it can be mixed with longer-chain oils to yield factice nearly as good as that made from long chain oils alone. Oil-resistant factice is made with castor oil.
Cross-linking the fatty-acid chains with sulfur (brown factice) or S2Cl2 (white factice) yields a rubbery material that improves the processing characteristics and ozone resistance of rubber. Varying the amount of factice changes the physical properties of the rubber; molded items might be 5–10% factice, extrusions 15–30%. Rubber erasers can have as much as 4 times as much factice as rubber in their composition.
References
Erhan, Selim M.; Kleiman, Robert (March 1973). "Factice from oil mixtures". Journal of the American Oil Chemists' Society. 70 (3): 309–311. doi:10.1007/bf02545313. S2CID 95493744. Archived from the original on April 12, 2013. Retrieved March 16, 2012. https://web.archive.org/web/20130412220011/http://naldc.nal.usda.gov/download/24579/PDF ↩
Simpson, Richard B., ed. (2002). Rubber Basics. Rapra Technology Ltd. pp. 133. ISBN 1-85957-307-X. 1-85957-307-X ↩
Erhan, Selim M.; Kleiman, Robert (March 1973). "Factice from oil mixtures". Journal of the American Oil Chemists' Society. 70 (3): 309–311. doi:10.1007/bf02545313. S2CID 95493744. Archived from the original on April 12, 2013. Retrieved March 16, 2012. https://web.archive.org/web/20130412220011/http://naldc.nal.usda.gov/download/24579/PDF ↩
Simpson, Richard B., ed. (2002). Rubber Basics. Rapra Technology Ltd. pp. 133. ISBN 1-85957-307-X. 1-85957-307-X ↩