Synthesis Of New Helical Substituted Polyacetylenes And Their Application Of Optical Active Composite Films

One-handed helical polymers can exhibit large optical activities. Therefore, these optically active helical polymers have been widely applied in many areas.Firstly, this paper studied the effect of the molecular weight of N-propargylamide helical polymers on their optical activities.When the molecular weight of polymers was low, the oligomer cannot adopt stable helical conformation; with the molecular weight increasing, both the intensity of CD signal and specific rotation rose rapidly in a certain range; and a further increase in the molecular weight gave rise to a little change in the intensity of CD effect and specific rotation.Secondly, poly(γ-benzyl-L-glutamate) macromonomer was synthesized by the ring-opening polymerization of NCA. These macromonomers were then polymerized via catalytic polymerization, yielding helical polymers with helical macromolecule chains in side chains.The optical activity and helical conformation were stable even in polarity solvent or at high temperature.Furthermore, with poly(vinyl butyral)(PVB) as the matrix, composite films containing substituted polyacetylenes were prepared. The composite films with achiral helical polymers or disordered polymers cannot possess optical activity; however, after being stretched, the composite films exihibited optical activity. With an increase in the stretching elongation and the helical polymer concentration, the optical activity of composite films rised.Heating also had an influence on the optical activity of composite films.Chiral helical polymer/PVB composite films exhibited optical activity without stretching. Moreover, stretching cannot influence the optical activity of composite films.