Influence of cohesive forces on the glass transition temperatures of polymers

The relationship between cohesive energy (c.e.) or cohesive energy density (c.e.d.) and the glass transition tenperature (Tg) of polymers has been re‐examined on the basis of literature data. For polymers with Tg above 25°C., there is no correlation between published or calculated values of c.e. or c.e.d. and Tg. However, for the rest of the polymers there is a linear relationship between c.e.d. and Tg, and a broad relationship between c.e. and Tg. These results imply that c.e.d. is the regulating, though not the only, factor in determining Tg's up to values of approximately 25°C.