What is Methanesulfonic acid?

Properties

Methanesulfonic acid has a melting temperature of 20 °C, the boiling point of 167 °C (13.33 kPa), 122 °C (0.133 kPa),  the relative density of 1.4812 (18 ℃) and refractive index 1.4317 (16 ℃). It is soluble in water, alcohol and ether, insoluble in alkanes, benzene and toluene. It will not subject to decomposition in boiling water and hot alkaline solution. It also has strong corrosion effect against the metal iron, copper and lead.

General Description

Methanesulfonic acid appears as colorless or slightly brown oily liquid, appearing as solid at low temperatures.It also has strong corrosion effect against the metal iron, copper and lead.It can be used as solvent, alkylation. It is the simplest of the alkylsulfonic acids. Salts and esters of methanesulfonic acid are known as mesylates (or methanesulfonates, as in ethyl methanesulfonate). It is hygroscopic in its concentrated form. 

Methanesulfonic acid may be considered an intermediate compound between sulfuric acid (H2SO4), and methylsulfonylmethane ((CH3)2SO2), effectively replacing an –OH group with a –CH3 group at each step. This pattern can extend no further in either direction without breaking down the –SO2– group. Methanesulfonic acid can dissolve a wide range of metal salts, many of them in significantly higher concentrations than in hydrochloric or sulfuric acid.

Application

Methanesulfonic acid is a raw material for medicine and pesticide. It can also be used as dehydrating agent, curing accelerator for coating, treating agent for fiber, solvent, catalysis, and esterification as well as polymerization reaction.

In the organic synthesis, it can be used as solvent, alkylation, catalyst of esterification and polymerization, also used in medicine and electroplating industry. It can also be applied to oxidation. Methanesulfonic acid is used as an acid catalyst in organic reactions because it is a non-volatile, strong acid that is soluble in organic solvents. It is convenient for industrial applications because it is liquid at ambient temperature, while the closely related p-toluenesulfonic acid (PTSA) is solid. However, in a laboratory setting, solid PTSA is more convenient. Methanesulfonic acid can be used in the generation of borane (BH3) by reacting methanesulfonic acid with NaBH4 in an aprotic solvent such as THF or DMS, the complex of BH3 and the solvent is formed.

Methanesulfonate electroplating solution

Methanesulfonate electroplating solution has been applied to tin and tin-lead alloy plating, the product features are as follows:

1. The bright pure tin electroplating of the methanesulfonic acid type with the coating crystal being meticulous, even and exhibiting bright silver-white. It has excellent weldability, being suitable in the electronics profession.

2. The plating solution has a high plating rate, a wide range of current density, faster deposition rate, and excellent deep plating capacity.

3. After the standard aging test or long-term storage, it can still maintain good welding performance.

4. It contains no fluorine boric acid with easy wastewater treatment, low corrosion, being environmentally friendly.

Preparation

Methanesulfonic acid can be obtained through the nitrate oxidation of thiocyanate methyl. Nitric acid and negative water are heated carefully to 80-88 °C with fractional addition of methyl thiocyanate and the temperature being automatically rose to about 105 ℃. After the reaction becomes mild, the reaction was heated to 120 ° C and reacted for 5 hours to obtain a crude product. The crude product was diluted with exchanged water and adjusted to pH 8-9 by addition of 25% barium hydroxide solution and filtered. The filtrate is condensed to until crystalline precipitation. The crystal is washed by methanol to remove the nitrate to obtain the barium methanesulfonate. It is then added to the exchanged water to boiling, add sulfuric acid for decomposition while it is hot, filter and the filtrate was concentrated under vacuum to no water to obtain the finished product.