Abstract: Oriented films of poly($gamma@-benzyl-L-glutamate), PBLG, were prepared by evaporation of solvent from solutions held in electric fields applied parallel to the film surface. Films thus aligned showed non-linear optical (NLO) activity, i.e., second harmonic generation (SHG). Order parameters calculated from FTIR spectra were correlated with second order susceptibility, and the effects of field strength, solution concentration, and molecular weight on these parameters were investigated. Alignment was observed at field strengths as low as 0.8 kV/cm, as indicated by polarized IR spectra. However, the extent of alignment as measured by IR spectra and values of the second order nonlinear susceptibility, X$+(2)$/, depend not only on field strength but also on solution concentration and the polymer molecular weight. Optimum conditions for alignment appear to be with a molecular weight of 118,000 D and a solution concentration of 2.5% (w/w). Dried films show the typical banded structures reported for polymer films oriented by mechanical shearing stresses. We have shown that these structures extend through the dried film as laminae perpendicular to both the film surface and to the field direction. !10
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