Polyacrylonitrile (PAN) is a synthetic resin prepared by the polymerisation of acrylonitrile. A member of the important family of acrylic resins, it is a hard, rigid thermoplastic material that is resistant to most solvents and chemicals, slow to burn, and of low permeability to gases. PAN fibre is therefore used in many different applications where these attributes are specified.

Polypropylene (PP) is a thermoplastic polymer used in a wide variety of applications including packaging, textiles and automotive components. It is rugged and unusually resistant to many chemical solvents, bases and acids making it an ideal material for use in Lead Acid Batteries and concrete.