Synthesis and optical properties of chiral helical polycarbodiimides

摘要

Chiral helical polymethylphenylethylcarbodiimides (Poly-PhEMCDI) and polymethylcyclohexylethylcarbodiimides (Poly-ChEMCDI) have been synthesized by insertion polymerization of corresponding monomeric carbodiimide using copper complex as initiator. Their circular dichroism, optical rotation power induced by ordered rigid main chain helical structure in solution and casting films were obtained and molecular weight dependent circular dichroism were studied. Primary results about Second Harmonic Generation (SHG) of casting films of polycarbodiimides prepared by different solvents were measured and chloroform was the best solvent to prepare casting films with preferential orientation of molecular helical structure. Polycarbodiimides can form lyotropic liquid crystal in chloroform, THF solution etc.