Lignosulfonates are one of a variety of synthetic chemicals that act as surfactants in many chemical processes. They are a group of organic compounds that include sulfonic acid, which acts as a substrate for chemical reactions and can be an important link between various chemicals, biological activity, and temperature. Sulfonyl groups are generally made up of sulfur atoms bonded together with an oxygen atom at the center. The term "ligno" refers to sulfur and has been used to refer to sulfuric acid since at least the time of the Roman Empire. In recent years, however, sulfonyl groups have found use in a variety of other applications, including plastics, synthetic rubbers, and drugs.
Sulfonylates, also known as sulfoform, are water-soluble organic polymers: that is, they are products of the chemical process by which wood is formed. In this case, lignosulfonates are produced when a gas such as argon is mixed with a liquid such as methylene chloride (an element used as a catalyst in many chemical processes), which undergoes conversion to a resulting compound called methylene hydroxide. The reaction of the methylene hydroxide with the surrounding atmosphere forms the compound methylene chloride and gives rise to many other compounds. Lignosulfonates are formed as a result of the reaction between the methylene chloride and the amino groups of proteins.
The most common form of lignosulfonate found in industrial materials is aqueous lignosulfonate. This compound is commonly used in the manufacturing of rubber and plastic parts because of its low cost and excellent physical properties. It is also widely used in the drying process for paper and cardboard, and in binding books, magazines, newspapers, and technical reports. In fact, aqueous lignosulfonates are the commonly used solvents for the printing industry, and especially inkjet printing and toner printing. Aqueous lignosulfonates are also used in the drying process for rubber-backed CD and DVD jackets.
Other forms of lignosulfate include granular, phorbic, and granular carbonate salts, which are less soluble in water but more so in solvents like acetone and chlorofluorocarbons (the most commonly used chemicals in fertilizer applications). Granular lignosulfate is commonly used for soil amendments, like fertilizer applications. Phorbic lignosulfate is employed for turf grasses, cottonseed meal, and marine grass among other applications. Granular carbonate salts are said to have the most extensive applications, and are said to be a perfect substitute for petroleum-based lubricants (e.g., hydraulic oils). Because these chemicals are insoluble in water, they enter the plant's root system to help keep the root system healthy.
Process of making Lignosulfonates
Lignosulfonates are made by the process of transesterification, wherein a crude lignosulfonic acid is mixed with mineral salts to produce the reaction product. Most common substances added to these chemicals are iron, calcium, magnesium, silicon, tin, and phosphorous. However, the combination of different aromatic chemicals can produce unique compounds that may be helpful in certain industries. Most of these organic substances used to develop lignosulfonate polymers are polysaccharides produced from cellulose, and some of these materials are known as mucopolysaccharides. Some of these organic chemicals that have proven useful in agricultural and manufacturing processes are glucosamine sulfate, guanidine hydroxide, alkyl sulfate, and mucopolydecyl ester.
Many people use lignosulfates for dust control because these chemicals bind to and absorb large amounts of dust in a short period of time. As a result, the dust is removed from the surface of objects or removed from the air surrounding an object after it has been placed in a lignosulfonic acid dust mixture. Lignosulfonates are also able to attract and bind to other naturally occurring elements, making them sticky and hard to remove from surfaces. In addition to their ability to bind to dust particles, some lignosulfonates have also been found to have anti-inflammatory and antioxidant properties. This makes them ideal for use in treating skin diseases such as psoriasis, eczema, and other inflammatory skin conditions.
Lignosulfonates are generally made through the process of transesterification. The chemical process involves two processes, aqueous suspension and hydrophobic moieties. The aqueous suspension is first prepared by taking aqueous solutions that contain lignosulfonic acid and making them denser. Next, the aqueous solution is passed through aqueous catalyzer where the pH and the concentration of the aqueous solution are adjusted. The aqueous solution is then purified and filtered, and then finally stored in a vacuum-sealed container. In order for lignosulfonates to be used in the final step of the transesterification process, the aqueous solution needs to be heated at approximately 100 degrees C for one to two hours.
The popularity of lignosulfonates is increasing in the construction industry due to their ability to provide a more durable finish to cement based projects. Because they are non-toxic and non-flammable, they are safe to use around young children and the elderly. Due to their structural strength, lignosulfonates are being used in a wide range of concrete applications including flooring, siding, driveways, and patios, and even in reinforced concrete to prevent buckling. With so many positive attributes, the lignosulfonates market is on the rise, and this is just the beginning.