Thermal depolymerisation of scrap polymers

Methods for recovering high purity monomer from scrap polymer are discussed, with particular reference to poly-methyl-methacrylate (commonly known as acrylic, Perspex™, Lucite™). Depolymerisation processes based on gas-fluidised beds and novel “mechanically fluidised” beds are described. These are proposed as environmentally friendly and energy-efficient alternatives to the conventional lead-bath or “Clementi” process for recovering methyl-methacrylate from acrylic scrap.