Relationship between the mechanical relaxations in the α zone and the calorimetric transitions in low density polyethylene

The α‐relaxation spectra of LDPE, irradiated and unirradiated, has been compared with their calorimetric thermograms. There exists a correlation between the two mechanical relaxations that appear in the α zone and the two fusion peaks observed in the calorimetric thermograms, confirming that the parameter that governs the temperature of the relaxations αI and αII is the most probable crystallite thickness, whereas the height of the α‐relaxation zone, as measured by means of tan δmax, depends on the total crystalline content of the sample.