The effect of condensed structure on cohesive energy density of polymer has always been ignored in the field of polymer physics.A method for estimating the CED value of crystalline non-polar polymers based on heat of fusion was first proposed in this paper.And the CED value of Poly (tetrafluoroethylene)

Polyethylene and Polypropylene in crystalline were estimated.The estimated CED value better explained those polymers for plastics but with lower CED value.Heat of fusion essentially reflects the difference of intermolecular dispersion forces in non-polar polymer between crystalline and amorphous state.Estimating the cohesive energy density of crystalline non-polar polymer based on heat of fusion responds to the definition of cohesive energy density and its characteristic.In theory

the estimating method applied to all crystalline non-polar polymers.