Preparation and graft copolymerisation of thiolated β-chitin and chitosan derivatives

β-Chitin was extracted from squid pens and deacetylated to β-chitosan. Both polymers were treated with tosyl chloride, potassium thioacetate and sodium methoxide to form 6-mercaptochitin and 6-mercaptochitosan, respectively. The degrees of substitution were lower for the chitosan derivatives and both types of polymer were less substituted than related polymers prepared from α-chitin. The thiolated polymers were reacted with MMA to form grafted copolymers. The solvent had an influence on the success of the polymerisation with the chitosan polymers giving highly grafted materials in aqueous acetic acid solution.