The On the basis of Spring Dashpot Model it is shown that the temperature dependence of the thermal diffusivity (of linear amorphous and semicrystalline polymers can be expressed as =0 exp (kTc / kT). where 0 and kTc are the measure of elasticity and flexibility of the polymeric chains, respectively. 0 and exp (kTc / kT) are the contribution of the recoverable and irrecoverable movements of polymeric chains to thermal diffusivity, respectively. Calculated values of of twenty-two polymers are in excellent agreement with the observed values, over a wide range of temperature including glassy, leathery and rubbery regions, maximum deviation being 6%. Further the evaluated glass transition temperatures Tg are also in close agreement with the reported values, maximum deviation being less than 4% for all the polymeric samples except P4MP1.
