Estimation of Crystalline Junction Size of Linear High-Density Polyethylene Gel Comprised of Lamellae

Abstract

A method for estimating junction point size in a thermoreversible gel made up of overlapping lamellae with disc-like morphology is proposed by combining the theory of melting temperature depression of copolymer-diluent system with the continuum percolation theory which takes account of the excluded volume of disc. According to our method, junction point size of gel can be estimated from measurement of gel-melting temperature Tmg* at the critical gelation concentration vc. This method was applied to linear high-density polyethylene (LHDPE)/xylene gel. The junction point size estimated by the present method, i.e., diameter and thickness of disc-like lamellae in a LHDPE gel, was in reasonable agreement with measurement by scanning electron microscopy (SEM) and small-angle X-ray scattering (SAXS) measurement.