Cross-linking of polyolefins : a study by thermoporosimetry with benzene derivatives swelling solvents

TL;DR

This study uses thermoporosimetry with specific benzene derivatives to analyze the pore structure of cross-linked polyolefins, revealing relationships between pore size, crystallization energy, and swelling behavior.

Contribution

It introduces calibrated solvents and exponential models to derive pore size distributions in cross-linked polyolefins using DSC thermoporosimetry.

Findings

Pore size distributions correlate with swelling degrees and irradiation doses.

Exponential relationships connect pore radii and crystallization energy with thermal data.

Calibrated solvents enable detailed pore structure analysis.

Abstract

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 γ-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.