Paraffin Guide

Paraffin wax (or simply "paraffin", but see alternative name for kerosene, above) is mostly found as a white, odorless, tasteless, waxy solid, with a typical melting point between about 47 °C and 64 °C ( 116.6°F to 147.2°F), and having a density of around 0.9 g/cm3.[3] It is insoluble in water, but soluble in ether, benzene, and certain esters. Paraffin is unaffected by most common chemical reagents, but burns readily.

Pure paraffin wax is an excellent electrical insulator, with an electrical resistivity of between 1013 and 1017ohm metre.[4] This is better than nearly all other materials except some plastics (notably teflon). It is an effective neutron moderator and was used in James Chadwick's 1932 experiments to identify the neutron.[5][6]

Paraffin wax (C25H52) is an excellent material to store heat, having a specific heat capacity of 2.14–2.9 J g−1 K−1 (joule per gram per kelvin) and a heat of fusion of 200–220 J g−1.[7] This property is exploited in modified drywall for home building material: it is infused in the drywall during manufacture so that, when installed, it melts during the day, absorbing heat, and solidifies again at night, releasing the heat.[8] Paraffin wax phase change cooling coupled with retractable radiators was used to cool the electronics of the Lunar Rover.[9] Wax expands considerably when it melts and this allows its use in thermostats for industrial, domestic and, particularly, automobile purposes.[10][11]

In industrial applications, it is often useful to modify the crystal properties of the paraffin wax, typically by adding branching to the existing carbon backbone chain. The modification is usually done with additives, such as EVA copolymers, microcrystalline wax, or forms of polyethylene. The branched properties result in a modified paraffin with a higher viscosity, smaller crystalline structure, and modified functional properties. Pure paraffin wax is rarely used for carving original models for casting metal and other materials in the lost wax process, as it is relatively brittle at room temperature and presents the risks of chipping and breakage when worked. Soft and pliable waxes, like beeswax, may be preferred for such sculpture, but "investment casting waxes," often paraffin-based, are expressly formulated for the purpose....