Para Toluene Sulphonic Acid

Synonyms Para Toluene sulphonic acid 4-Methylbenzene sulphonic acid 

Molecular formula C7HgS03 (Anhydrous) C7H10SO4 (Monohydrate) 

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Sulpho Benzoic Acid.— When toluene is sulphonated with concentrated sulphuric acid a mixture of ortho and para toluene sulphonic acid is obtained. 

Polymers that are insoluble in solvents may be dry ashed in the presence of metal retaining agents (e.g. para-toluene sulphonic acid, PTS A) and the ash residue dissolved in 0.1M HC1... 

Further studies have also appeared in the mass transfer properties of the modifying layers. The mass transfer behavior of the polymer [Os(bipy)2(PVP)ioCl]Cl in para-toluene sulphonic acid has been studied in de-tail. In this study the effect of the non-rigidity of the layer on the mass transport data is discussed in some detail. A detailed study of the pH dependence of the mass transfer of a glassy carbon electrode modified with the [Ru(bipy)2(PVP)io(H20)] is reported. This study shows that the EQCM can be used very effectively for the study of redox reactions which show complicated (in this case pH dependent) features. (See also Section 8.2). 

Ragunathan et al. [182] have reinvestigated CPMAS NMR spectra for polyaniline doped with 5-sulphosalicyclic acid and para-toluene sulphonic acid. The results are summarized in Table 12.20. 

Emeraldine base Polyaniline doped para-toluene sulphonic acid x = 0.38% jc= 10.5%... 

In order to illustrate the impact on future processes we are pleased to give herewith the following comparison to produce valuable product widely used namely Para Toluene Sulphonic Acid (PTSA). The current process for manufacturing this chemical is sulphonation of toluene at high temperatures in a glass lined reactors using 98 % Sulphuric acid. 

The new process involved would be at low temperature and would not require any Sulphuric Acid for the sulphonation of toluene to produce Para Toluene Sulphonic Acid (PTSA). 

Fig. 8.1 Process currently employed to manufacture para toluene sulphonic acid...

Para Toluene Sulphonic Acid widely used as plasticizers, additive in foundry chemicals, production of cresols, additive in detergents as sodium salts and other chemical reactions. These are outlined as below -... 

Curing temperatures below 120°C are obtained by additions of acids, such as para-toluene sulphonic acid, acid butyl phosphate, acid butyl maleate or special proprietory catalysts. The combination of acid catalysis and a highly reactive melamine formaldehyde resin can result in curing temperatures as low as 80°C. In such cases the paint formulator must pay careful attention to pigment and viscosity stabilities to ensure that flocculation of the pigment does not occur. Viscosity is normally controlled by primary alcohols in the solvent blend (at least 20% of total solvent). 

Hexamethoxymethyl melamine (HMMM) resins are less reactive than butylated melamine resins and always require the incorporation of acid catalysts to cure the coating. Para-toluene sulphonic acid (1-2% on total resin) is used extensively in hydroxy aciylic/HMMM formulations. 

It is advisable to include some carboxy functionality also as the cure reaction between acrylic and melamine resins is acid catalysed. In the more sophisticated industrial markets for acrylics, stoving temperatures are well controlled and adequate cure cycles are achievable. However, in the competitive general metal finishing market, low temperatures and short times are common, so whilst it is possible to externally catalyse using PTSA (para toluene sulphonic acid), this polar material remains in the film after curing to act as a pathway for water. Blistering on exposure to humidity is a common problem in acrylic-melamine systems which have been catalysed by sulphonic acids. 

Add A/B mixture to C, filter and add immediately prior to use para-toluene sulphonic acid solution to pH = 1.5. 

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