4,4’-methylene-bis(ortho-chloroaniline) or MOCA, has been a mainstay in the polyurethane elastomer industry for over 50 years. MOCA is employed as the chain extender and curing agent in TDI based polyurethanes. It is commonly used in the pipeline pigging industry. MOCA is favoured because:

• It can provide superior all round technical properties which comes from the unique molecular structure of the molecule which helps the elastomer to form alternating hard and soft segments.
• Lower cost compared to alternative curing agents.
• It is easily processed, meaning it can be used to cast small, medium and large parts.
• It is robust in its use so that slight variations in the reactants do not impact the characteristics of the final product compared to alternatives.
• It is easy to control the reaction rate.
• It can be used with nearly any TDI capped prepolymer.
• There is a long history of formulation and processing knowledge.