Tag Archives: rust inhibitor

Acid inhibitors

Acid inhibitors, in terms of metal manufacturing and handling can also be called acid corrosion inhibitors, rust preventatives or rust preventives (commonly termed or referred as Rodine). In essence, these are products that are used to permit corrosion protection to metals from strong and corrosive mineral acids like hydrochloric acid, nitric acid, sulfuric acid, sulfamic acid, hydrofluoric acid, phosphoric acid etc., and organic acids such as Cirtic Acid, Oxalic Acid, Formic Acid, Tartaric Acid, EDTA etc. against various applications as Acid Corrosion Inhibitors. Some of the applications are named as follows:-

  • Acid plant cleaning (CIP)
  • Heat exchanger, boilers and equipments descaling
  • Acid pH adjustment
  • Acid Pickling operations
  • Removal of CaCO3 in Oil Well Acidizing
  • HCL Acid Inhibitor (Rodine 213, Rodine 213 Special, Rodine 214, Rodine 103, Rodine 52)
  • Sulfuric Acid Corrosion Inhibitor (Rodine 130)
  • Sulfamic Acid Corrosion Inhibitor (Rodine 31A, Rodine 102)
  • Acid Pickling Corrosion Inhibitor (Rodine 85, Rodine 95, Rodine 50, Rodin 55, Rodine 130)

Citric Acid Inhibitor:

Citric acid is a weak organic acid. It is a natural preservative/conservative and is also used to add an acidic, or sour, taste to foods and soft drinks. In biochemistry, the conjugate base of citric acid, citrate, is important as an intermediate in the citric acid cycle, and therefore occurs in the metabolism of virtually all living things.


The inhibition effect of citric acid on the corrosion behaviour of aluminium in 2M NaCl solution (pH 2) was studied with the help of potentiodynamic polarisation, electrochemical impedance spectroscopy (EIS) and linear polarisation resistance (LPR) techniques. The experimental results showed that citric acid inhibits the corrosion of aluminium in NaCl solution and the inhibition efficiency depends on its concentration. The protection efficiency increases with citric acid concentration up to a critical value of 1·0 × 10M. At higher concentrations, the inhibition efficiency reduced again with increasing concentration. The mechanism of inhibition was attributed to the adsorption of citric acid onto the metal surface at the time of cleaning, and de-scaling. We make use of high quality machines that insure accuracy in the formation of our mixtures.


Acetic Acid Inhibitor, Formic Acid Inhibitor:

Acetic is an organic compound with the chemical formula CH3CO2H (also written as CH3COOH). It is a colourless liquid that when undiluted is also called glacial acetic acid. Formic acid (also called methanoic acid) is the simplest carboxylic acid. Its chemical formula is HCOOH or HCO2H. It is an important intermediate in chemical synthesis and occurs naturally, most notably in the venom of bee and ant stings.


Corrosion behaviour of copper has been investigated in different compositions of formic acid and acetic acid at 30 °C by a potentiostatic method. The maximum corrosion rate was found in 20–40 mol/o formic acid and in 20 mol/o acetic acid in aqueous solution mixtures. The corrosion rate depended on the concentration of either acid. Formic acid is observed to be more corrosive than acetic acid. The metal exhibited active-passive behaviour in the concentration range of 30–70 mol/o of HCOOH acid in the solution mixture. A short passivity range of potential with a high passivity current density was observed for the metal in the solution mixtures of HCOOH acid while in solution mixtures of acetic acid the metal exhibited only active dissolution.


The acetic acid and formic acid are fully organic acids that come to use in the systems for the purpose of mild cleaning, de-rusting, ph adjustment and de-scaling of applications.

Application: Multiple applications for metal surface treatment, cleaning, descaling & derusting for various industries.



Chemical Type:  Blend of specialized chemical compounds

Form:  Liquid

Specific Gravity:  Ranges from 1.0 – 1.2 depending upon product

Ph:  Product Specific

Solubility:  Soluble in Water


Dosage: Dosage depends on product, application, acid type and concentration and operating temperature. The specific dosage rates and method will be specified by the Chemtex technical representative.


Major Benefits: Metal Protection Wetting properties for effective cleaning.


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Industrial Coolant Antifreeze Chemical

Propylene glycol is used as antifreeze agent and industrial coolant in different industries where contamination with food is possible, de-icing solutions etc. Propylene glycol is generally regarded as safe for use in food. It is used in the industries like food, beverage etc for heat transfer, also used in vehicles. Antifreeze Coolant should be efficient in transferring the heat as well as preventing scale and corrosion.


Propylene glycol [HO-CH2-CH(OH)-CH3] is pronounced as pro’puh-leen-gly’col. It is a clear, colorless, slightly syrupy liquid at room temperature. The compound may exist in air in the vapor form though it must be heated or briskly shaken to produce a vapor. It is actually a multi-variant chemical compound. Propylene glycol – in an industrial cooling and heating process terminology is referred as industrial coolant or heat transfer fluid (HTF) or the common fluid that is used in large installations for transporting heat from one place to another.



  • serves as a solvent
  • offers outstanding stability with high flash and boiling points
  • reduces the freezing point
  • increases the boiling point
  • helps to bind and transport other substances (excipient)
  • holds and dissolves active ingredients equally in a medium
  • connects and stabilizes insoluble fluids (emulsifier)
  • attracts/holds water/moisture (hygroscopic)



  • As an emulsification agent in Angostura and orange bitters
  • As a moisturizer in medicines, cosmetics, food, toothpaste, shampoo, mouth wash, hair care and tobacco products
  • As a carrier in fragrance oil
  • To produce polyester compounds
  • As a base in deicing solution
  • In smoke machines to make artificial smoke for use in firefighters’ training and theatrical productions
  • As a solvent for food colors and flavorings
  • As an ingredient, along with wax and gelatin, in the production of paintballs
  • As a wetting agent, used to determine drying time in paints and coatings


A non-toxic substitute of Ethylene Glycol:

Propylene Glycol is the replacement of Ethylene Glycol in newer automotive antifreezes and de-icers in aircrafts. Like Ethylene Glycol, Propylene Glycol also has the special physical characteristics of depression of freezing point when mixed with water. It happens due to disruption of hydrogen bonding. Pure water freezes at 0OC. But aqueous solution of Propylene Glycol (10% by weight) has a freezing point of -3OC. 30% by weight aqueous solution of Propylene Glycol freezes at -12OC and a 60% by weight Propylene Glycol and water mixture can further lower down this freezing point to -51OC.


Why Glycol turned into red color?

Because of the extensive corrosion & rust in the system metal makes the glycol turn reddish in color. At this point the glycol is fouled with iron contaminants that increase the glycol degradation rate. It is important to add corrosion inhibitor to the glycol system to avoid such degradation of glycol.


Application Areas:

Beverages & Juices, Breweries & Distilleries, Packaged Food Freezing, Canneries & Preservers, Fish Processing Units, Pharmaceutical & Bulk Drugs, Poultry Processing Industry, Thermal Storage System, Heating and Cooling Systems, Snow Melting and Refrigeration, Ice Skating Rinks, Vegetable Oil Industry, Ice Manufacturer, Cold Storage Systems etc.


Product Physio-Chemical Data:

  • Form and Appearance – Clear, colorless liquid
  • Assay as Propylene Glycol – 99.8%
  • Specific Gravity – 1.04 (approx.)
  • Molecular Wt. –  76.0548 gm/mol
  • Solubility in Water – 100%


Handling Measures, Precaution & Storage:

Propylene Glycol is slightly hygroscopic & the storage temperature is not critical, it must be stored under conditions so that contamination with water and adsorption of moisture are prevented. It should be noted however for product quality reasons the storage temperature should not go above 40°C. At below freezing temperatures the product viscosity might become too high for transfer from the storage containers with the pumps available. PG is a stable chemical and is not expected to deteriorate significantly with time provided if it is stored as indicated. The drums should be stored in dry condition, better to use the original drums rather than the other drums and if the drums are opened then it must be closed tightly at unused situation. The chemical can be stored up to 6 months.

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