logo

What are Stabilizing Agents, their Types and Applications?

Stabilizer is basically something that stabilizes something such as a substance added to another substance to prevent an unwanted alteration of physical state of that substance.

What are Stabilizing Agents, their Types and Applications?

What are Stabilizers or Stabilizing Agents?

Stabilizer is basically something that stabilizes something such as a substance added to another substance to prevent an unwanted alteration of physical state of that substance.

"In chemistry, a stabilizer is a chemical which tends to inhibit or prevent the reaction between two or more other chemicals".

It can be thought of as the antonym to a catalyst. Stabilizer is also a substance or chemical that inhibits the separation of suspensions, emulsions and foams. There are mono-functional, bi-functional, and poly-functional stabilizers. There are many types of stabilizers which play a very important role in our daily lives like antioxidants. Stabilizer basically stabilizes a chemical reaction to protect the material from harmful effects that would affect it otherwise.

Types of Stabilizing Agents

Antioxidants

Antioxidants are substances which prevent the unwanted oxidation of materials. They inhibit oxidation reactions by free radicals in the human body before they can do any harm.
For example, glutathione, vitamin C, vitamin A, and vitamin E as well as enzymes such as catalase, superoxide dismutase and various peroxidases.

Sequestering Agents

Sequestering agents form chelate complexes and inactivates traces of metal ions that would otherwise act as catalysts and become inconvenience for different processes that are to be applied on materials, hence they inhibit the action of metallic ions by forming complexes. For example, EDTA and DTPA.

Emulsifier

An emulsifier, also known as an emulgent, is a substance that stabilizes an emulsion by increasing its kinetic stability and inhibits the separation of dispersed liquids which are dispersed into another medium. For example, egg yolk, soy lecithin, DATEM.

Bleach Stabilizer

Bleach stabilizer are chemical substances which are used to stabilize or control the liberation of bleaching species (per hydroxyl ions, Chlorine dioxide) from the bleaching agent (E.g., H2O2 , NaClO2 ) in textile bleaching to prevent the decomposition of bleach and also acts as a buffer to maintain the pH of bleaching bath at optimum level. It also prevents the degradation of fibres.

There are various types of bleach stabilizers:

  • Alkali-based Stabilizer: Caustic soda (NaOH), Sodium carbonate (Na2CO3), silicates.
  • Dispersants: Acrylates, Phosphonates etc.
  • Inorganic Stabilizer: Magnesium salts.

Scavengers

A scavenger in chemistry is a chemical substance added to a mixture in order to remove or de-activate impurities and unwanted reaction products, for example oxidation, to make sure that they will not do any unfavorable reactions.

Scavengers can be used in textile industry as stabilizers against light-induced polymer degradation eliminating the free radicals formed by ultraviolet radiation. The most commonly used scavenger is Hindered amine light stabilizers (HALS).

Ultraviolet stabilizers

Ultraviolet stabilizers are the ones which protect the various materials, especially plastics, from harmful effects of ultraviolet radiation. There are 2 kinds of Ultraviolet stabilizers.

  • UV absorbers: Chemicals absorbing ultraviolet radiation and preventing it from penetrating the materials, principally the same as sunscreens.
  • Quenchers: Dissipating the radiation energy as heat instead of letting it break chemical bonds, often organic nickel salts.

Application areas of Stabilizers

  1. Hydrogen peroxide bleach stabilizers are most widely used in the bleaching of cellulosic fibers [cotton, flax, linen, jute etc.] and wool, silk, nylon and acrylics with hydrogen peroxide. Stabilizer is used to control or regulate the liberation of per hydroxyl ions to prevent rapid decomposition of bleach and prevents the degradation of fibers by metal traces.
  2. Caprolactam, ethylene glycol, glutamines and glutamic acid are used as stabilizers for hydrogen peroxide bleaching.
  3. Chlorine dioxide, stabilizer in sodium chlorite bleaching, is sometimes used for bleaching of wood pulp in combination with chlorine, but it is used alone in ECF (elemental chlorine-free) bleaching sequences. It is used at moderately acidic pH (3.5 to 6). The use of chlorine dioxide minimizes the amount of organochlorine compounds produced.
  4. Antioxidants are used to stabilize or deactivate the reactive oxygen species (ROS) which encompasses all highly reactive, oxygen containing molecules including free radicals.
  5. Antioxidants are used as food additives to help guard against food deterioration. Exposure to oxygen and sunlight are the two main factors in the oxidation of food.
  6. Antioxidants are used in fuels and lubricants to prevent oxidation, and in gasoline to prevent the polymerization that leads to the formation of engine-fouling residues and in polymers such as rubbers, plastics and adhesives to prevent the oxidative degradation that causes a loss of strength and flexibility in these materials.
  7. Sequestering agent is used to inhibit the chemical reactions of traces of metal by converting them into chelating complexes. E.g., EDTA & DTPA.
  1. UV stabilizers are used frequently in plastics, including cosmetics and films. The primary function is to protect the substance from the long-term degradation effects from light, most frequently ultraviolet radiation.
  2. UV stabilizers, such as benzophenones, work by absorbing the UV radiation and preventing the formation of free radicals.
  3. Dispersing agents or plasticizers are added to process liquids to prevent unwanted deposits by keeping them finely dispersed. They function in both aqueous and non-aqueous media.
Muhammad Rehan Ashraf

I am a Textile Engineer, founder and editor of "Textile Trendz". Currently working in an export-oriented textile organization. I love to share my knowledge about textiles.