Polyacrylamide (PAM) is a synthetic polymer composed of repeating units of acrylamide, which is derived from the monomer acrylic amide. The molecular structure of polyacrylamide is a long chain polymer with a linear backbone. Each repeating unit consists of an acrylamide monomer, which has the following chemical structure:

        H2C=CHCONH2

The acrylamide monomers in polyacrylamide are connected through covalent bonds, forming a linear chain. The polymerization process involves the reaction of acrylamide monomers together, which results in the formation of polyacrylamide chains with various lengths.

The molecular weight and properties of polyacrylamide can be controlled by adjusting the reaction conditions and the ratio of monomer to initiator. Polyacrylamide chains can have a wide range of molecular weights, from a few thousand to several million Daltons.

Polyacrylamide is commonly used in various applications due to its water-soluble nature, high molecular weight, and ability to form gels. It is extensively used in processes such as water treatment, paper and pulp industry, oil and gas drilling, mining, and gel electrophoresis in molecular biology.