Stereoregularity of grafted polyacrylonitrile prepared by liquid phase graft polymerization to polycaproamide fibre

The stereoregularity of grafted polyacrylonitrile (PAN) was studied in polycaproamide (PCA)-PAN graft copolymers, prepared by chemically initiated liquid phase graft polymerization on fibres. It was found that the stereoregularity of grafted PAN cannot be reliably determined by 13C NMR spectroscopy. By IR spectroscopy, the presence of absorption bands characteristic of isotactic PAN triads was revealed in graft copolymers. These results were confirmed by X-ray structural analysis. By spectroscopic analysis of polyacrylic acid prepared by polymer-analogous transformation of PAN, the stereoregular isotactic structure of grafted PAN was established.