Candles do not have a fixed melting point. Take paraffin wax candle for example.When the temperature reaches above 40 degrees Celsius, the candle begins to soften, and when the temperature reaches about 70 degrees Celsius, the candle becomes liquid. Because paraffin, the main component of candles, is a mixture, it is amorphous (amorphous is not a solid. Amorphous can be regarded as an extremely viscous liquid. Its thermal conductivity is not high, and heat energy can easily be converted into flow between particles. , so there is no fixed melting point), so candles have no fixed melting point.
The main raw material of candles is paraffin (C₂₅H₅₂). Paraffin is produced from the waxy fraction of petroleum by cold pressing or solvent dewaxing. It is a mixture of several higher alkanes, mainly n-docosane (C22H46) and n-dioxane. Octadecane (C28H58) contains about 85% carbon and 14% hydrogen. The added auxiliary materials include white oil, stearic acid, polyethylene, fragrance, etc. Among them, stearic acid (C17H35COOH) is mainly used to improve the softness. The specific addition depends on the type of candle produced.
Candles melt easily and are less dense than water and difficult to dissolve in water. It melts into a liquid state when heated. It is colorless and transparent and easily volatile when heated slightly. The unique smell of paraffin can be smelled. When cold, it solidifies into a white solid with a slight special smell.
