Key Difference – Acrylamide vs Polyacrylamide
Acrylamide and Polyacrylamide are two amide molecules, but acrylamide is a single molecule and Polyacrylamide is a polymer (a large molecule which is formed by monomers) which is produced from the monomers (a molecule that can be bonded to other identical molecules to form a polymer) of acrylamide. In other words, the key difference between acrylamide and polyacrylamides is that polyacrylamide is a polymer and acrylamide is the sub unit used to produce polyacrylamide molecules. Therefore, acrylamide is considered as a small molecule whereas polyacrylamide has a high molecular weight. Due to this fact, their chemical properties and industrial applications vary from each other.
What is Acrylamide?
Acrylamide is also known as acrylic amide, and its IUPAC name is prop-2-enamide. It is an amide with the molecular formula C3H5NO. It is found as a white crystalline solid which decomposes in the presence of acids, bases, oxidizing agents, iron and iron salts. The non-thermal decomposition of acrylamide leads to the formation of ammonia whereas thermal decomposition produces carbon monoxide (CO), carbon dioxide (CO2), and oxides of nitrogen. It is water soluble and as well as soluble in ethanol, ether, and chloroform. One of the methods of producing acrylamide is from the hydrolysis of acrylonitrile by nitrile hydratase.
What is Polyacrylamide?
Polyacrylamide is a polymer molecule which is produced by the polymerization of acrylamide units. In other words, the monomer used to produce polyacrylamide is acrylamide. It is abbreviated as PAM, and its IUPAC name is poly (2-propenamide) or poly (1-carbamoylethylene). The hydrated form of polyacrylamide is highly water absorbent and forms a soft gel when it is hydrated. It is used in industrial applications such as polyacrylamide gel electrophoresis and for producing soft contact lenses.
What is the difference between Acrylamide and Polyacrylamide?
Molecular Formula:
Acrylamide: The molecular formula of acrylamide is C3H5NO.
Polyacrylamide: Polyacrylamide molecules are produced from acrylamide molecules by polymerizing in simple linear form or cross-linked form.
Properties of Acrylamide and Polyacrylamide:
Acrylamide: Acrylamide is a colorless, odorless highly water soluble crystalline amide which can be polymerized rapidly to form polymeric compounds. It is considered as a carcinogen, skin irritant, and may be a cancer initiator in the skin.
Polyacrylamide: Polyacrylamide is highly water absorbent molecule and forms a soft gel when it is hydrated. This property has several advantages in some industrial applications such as manufacturing soft contact lenses.
Uses of Acrylamide and Polyacrylamide:
Acrylamide: Acrylamide is used in large quantities to produce various polymers. In addition, it is used as a thickening or flocculating agent in grout, cement or in sewage/water treatment processes, pesticide formulations, cosmetics, sugar manufacturing, ore processing, food packaging, soil erosion preventing, plastic and paper manufacturing. Moreover, it is also used as a chemical intermediate in the production of N-methylol acrylamide and N-butoxyacry. It is also used in some potting soil as well.
Polyacrylamide: Polyacrylamide is mainly used to flocculate solids in liquids. This process is applied in water treatment, screen printing, and paper making. Another use of polyacrylamide is using as a soil conditioner, frequently used in horticultural and agricultural to control soil erosion. In addition, it is commonly used in the filed of molecular biology as a medium for electrophoresis of proteins and nucleic acids. It has been recently identified as sub-dermal filler in facial surgeries. The straight-chain from of polyacrylamide is used as a thickener and suspending agent. It is also used for producing soft contact lenses.
Image Courtesy:
1. Methacrylamide skeletal By Ed (Edgar181) – Own work, [Public Domain], via Wikimedia Commons
2. Polyacrylamide By Roland Mattern (Roland1952) [Public domain], via Wikimedia Commons
