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