Indopol polybutenes are synthetic hydrocarbon polymers made by polymerization of C4 olefins (primarily isobutene), and are available in a wide range of low viscosities. All Indopol L grades are colourless, practically non-toxic, and exhibit little or no odor. They are non-drying and do not leave residues when volatilized or thermally decomposed. They are hydrophobic, can easily be emulsified, and are resistant to oxidation by light and moderate heat. Indopol polybutenes possess an olefinic double bond at the end of each molecule that makes them amenable to many chemical derivatisation reactions.