STRUCTURE AND INTERACTIONS IN HOMOPOLYMERS AND BLENDS AS STUDIED BY THE METHODS OF VIBRATIONAL AND NMR-SPECTROSCOPY

The combination of IR, Raman and NMR spectroscopy was used in the stud y of the blends of semicrystalline and amorphous polymers with conside rably different strength of intermolecular interactions: poly(epsilon- caprolactam)/polystyrene (PCL/PS), poly(ethylene oxide)/poly(methyl me thacrylate) (PEO/PMMA) and poly(N-methyllaurolactam) /poly(4-vinylphen ol) (PNMLL/PVPh). In the vibrational and NMR spectra of the blends com posed of non-interacting polymers (PCL/PS) and weakly interacting poly mers (PEO/PMMA), no band changes were observed which would indicate ch anges of the conformational structures. H-1 NMR relaxation of the PCL and PS components in the blends is the same as in the respective homop olymers similarly treated. In the blends of weakly interacting polymer s (PEO/PMMA), the crystallinity of PEO is influenced by the presence o f PMMA and is negligible in the blends with less than 30 wt.% of PEO. The rotating-frame spin-lattice relaxation time for protons T-1 rho(H) of PMMA indicates close contact of the PMMA and PEO chains. In the bl ends PNMLL/PVPh with strong hydrogen-bonding interactions, both compon ents are intimately mixed on a scale of 3-4 nm and significant shifts of some bands both in vibrational and in NMR spectra reveal changes of structure.