THE STERIC EFFECT OF SOLVENT MOLECULES IN THE DISSOLUTION OF POLYACRYLONITRILE FROM 5 DIFFERENT N,N-DIMETHYLFORMAMIDE DERIVATIVES AS STUDIED USING RAMAN-SPECTROSCOPY
M. Minagawa et al., THE STERIC EFFECT OF SOLVENT MOLECULES IN THE DISSOLUTION OF POLYACRYLONITRILE FROM 5 DIFFERENT N,N-DIMETHYLFORMAMIDE DERIVATIVES AS STUDIED USING RAMAN-SPECTROSCOPY, Polymer, 37(3), 1996, pp. 463-467
The steric effect of solvent molecules in the dissolution of polyacryl
onitrile (PAN) from five different kinds of N,N-dimethylformamide (DMF
) derivatives was studied using Raman spectroscopy and a laboratory co
nstructed laser optical instrument. The dissolution behavior of PAN fr
om solvents such as DMF, N,N-dimethylacetamide, N,N-diethylformamide,
N,N-dimethylcarbamylchloride, and N,N-dimethyltrichloroacetamide was s
tudied with the laser optical method. Raman spectra of the solvents an
d solutions provided significant information on the intermolecular int
eraction between nitrile and the solvents (i.e., dipole-dipole interac
tion). The carbonyl band in each solvent shifted from a lower to a hig
her frequency when nitriles were added, and the extent of the shift wa
s directly related to the structure and geometry of a subtituent in ea
ch solvent molecule. An inverse linear relationship between the value
of the dissolution temperature (T-sol) and the extent of the Raman car
bonyl shift is demonstrated. It seems reasonable to explain this in te
rms of the steric effect of solvent molecules in the dissolution of PA
N.