Cross-Linking of Polyolefins: A Study by Thermoporosimetry with Benzene Derivatives as Swelling Solvents
✍ Scribed by Nicolas Billamboz; Jean-Marie Nedelec; Manuel Grivet; Mohamed Baba
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 278 KB
- Volume
- 6
- Category
- Article
- ISSN
- 1439-4235
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The solvents o__‐,__ m__‐,__ p__‐xylene,__ p__‐dichlorobenzene, 1,2,4‐trichlorobenzene, and naphthalene were calibrated as condensates used in the thermoporosimetry technique. Exponential relationships were found connecting the pore radii__ R~p~ (in nm) and the freezing‐point depression of the swelling solvent Δ__T (in °C) on the one hand and the apparent energy of crystallization W~a~ (in J cm^−3__^) and Δ__T on the other hand: ${{\rm R}{_{p}}={\rm t},exp[- 1/({\rm c}{\Delta}{\rm T})]}$;__ ${{\rm W}{_{a}}={\rm W}{_{0}},exp({\Delta}{\rm T}/{\rm f})}$. Pore‐ or mesh‐size distributions can be derived from differential scanning calorimetry results by using the following equation: ${d{\rm V}{_{p}}/d{\rm R}{_{p}}={\rm k}{[{\rm cY}({\rm T}){\Delta}{\rm T}{^{2}}]/[{\rm W}{_{a}}{\rm R}{_{p}}]}}$. All the numerical parameters were determined. Polyethylene and polypropylene samples, cross‐linked with high‐energy electrons or γ‐rays, were submitted to thermoporosimetry study. Relative mesh‐size distributions, which depend on the polymer/solvent pair, were calculated for these polyolefins with o__‐,__ m__‐, and__ p__‐xylene as solvent and were found to be in the same sequence as those of their degrees of swelling and the irradiation doses received.__