Cross-linking of polyolefins : a study by thermoporosimetry with benzene   derivatives swelling solvents
  o, m, p-xylene, p-dichlorobenzene, 1,2,4 trichlorobenzene and naphthalene were calibrated as condensates used in thermoporosimetry technique. Exponential relationships were found connecting the pore radii (Rp(nm)) and dT (C) on one side and the apparent energy of crystallization (Wa (J.cm-3)) and dT on the other side: Pore or mesh size distribution can be derived from DSC thermal recording using the following equation: All the numerical parameter values were determined. Polyethylene and polypropylene samples, cross-linked with high-energy electrons or &#947;-rays, were submitted to thermoporosimetry study. The mesh size distributions (MSD) calculated for these polyolefins, using o, m and p-xylene as solvent, were found in the same sequences that their degrees of swelling and the irradiation doses they received. 
Nicolas Billamboz (LMNAC), Jean-Marie Nedelec (LMI), Manuel Grivet   (LMNAC), Mohamed Baba (PMM)