Controlled synthesis of photosensitive graft copolymers with high azobenzene-chromophore loading densities in the main and side chains by combining ATRP and ADMET polymerization

Photosensitive graft copolymers containing azobenzene chromophores in the main and side chains were successfully synthesized by combining living atom transfer radical polymerization (ATRP) and acyclic diene metathesis (ADMET) chemistry based on the results of proper heterodifunctional inimer and azobenzene monomer design. The precise copolymer architectural features were manipulated by combining the macromonomer technique and the macroinitiator method. The as-prepared copolymer containing azobenzene chromophores in the main and side chains showed unique reversible isomerization processes, suggesting that the photoisomerization of azobenzene chromophores occured mainly in one of the two types of azobenzene groups in the main or side chains with similar probabilities due to their main and side-on structure.