Chemical modification of poly(vinyl chloride) (PVC) by dehydrochlorina
tion with ethanolic KOH is found to yield modified PVC with conjugated
polyene sequence. The semiconducting nature of ethoxide-modified PVC
is illustrated with temperature dependence of conductivity (sigma). Th
e relative ratios (r) of conductivity, sigma(modified PVC)/sigma(unmod
ified PVC), are greater than unity in the temperature range 50-degrees
- to 180-degrees-C, r being maximum in the vicinity of glass-transitio
n temperature (T(g)). T(g) inferred from conductivity-temperature prof
iles is found to be greater for modified PVC relative to unmodified PV
C, which is explicable in terms of restricted free rotation limiting s
egmental motion. For comparison with the conductivity and T(g) of etho
xide-modified PVC, LiCl-modified PVC and (aniline + S2O82-)-modified P
VC have also been studied.