Paraffin is a solid crystallized product extracted from petroleum. It is a mixture of hydrocarbons, i.e. hydrocarbons of different molecular weights. It is mainly composed of normal alkanes, and also contains some solid isoparaffins, cycloalkanes and a small amount of aromatic hydrocarbons. The number of carbon atoms of commercial paraffin wax is generally 22 to 36, the molecular weight range is 360 to 540, and the boiling point range is 300 to 550 degrees Celsius. As the molecular weight, boiling point and melting point of paraffin increase, the number of n-alkanes in the composition decreases and the number of iso-alkanes and solid cycloalkanes increases. The chemical composition of paraffins of different crude oils also differs.
Yellow paraffin wax or poorly refined wax needs attention!
Yellow paraffin or poorly refined wax still contains trace amounts of non-hydrocarbon components. These complex sulfur, nitrogen, and oxygen mechanisms The compound, although only contained in trace amounts, greatly reduces the stability of paraffin wax. Some condensed ring aromatic hydrocarbons in the small amount of aromatic hydrocarbons contained in paraffin wax are harmful to the human body. Therefore, as paraffin wax used in the food industry and medicine, the condensed ring aromatic hydrocarbons must be reduced below the specified index before it is allowed to be used.
Using a mass spectrometer to analyze certain paraffin waxes in the laboratory, the chemical composition data of each fraction divided by the number of carbon atoms in the molecule showed that the carbon in the molecule The fractions with smaller atomic numbers are all normal alkanes. As the number of carbon atoms increases, the content of isoparaffins and cycloalkanes increases. The aromatic hydrocarbons in the wax only appear in the fractions with high carbon atoms. Therefore, when the refining conditions are the same, in general commercial paraffin wax, the content of condensed ring aromatic hydrocarbons in low-grade paraffin wax is lower than that in high-grade wax.