An efficient route for the synthesis of graft copolymers with rigid backbones via anionic ring-opening polymerization of caprolactam

Epsilon-caprolactam (CL) has been grafted onto rigid backbones to form graft copolymers via anionic ring-opening polymerization in the presence of catalyst sodium caprolactam. An allyl monomer containing N-carbamated caprolactam group was copolymerized with different rigid monomers to form the rigid backbones, which acted as the macroactivators of anionic polymerization. The time for the completion of anionic polymerization was less than 30 min. The graft copolymers were evaluated by differential scanning calorimetry and selective solvent extraction technique consisted of using methanol and chloroform as extracting solvents. The polymerization of CL in the presence of synthesized macroactivators yielded graft copolymers with high purity. The evaluation performed by thermogravimetric analysis indicated that graft copolymers had improved thermal stabilities.