Gel melting temperature and structure of junction zone in thermoreversible gels of linear low density polyethylene/decalin systems

Melting process of linear low density polyethylene/decalin thermoreversible gels was measured by the falling ball method (FBM), defferential scanning calorimetry (DSC), and polarized optical microscopy. The number of monomers per chain zeta and number of chains (s) contained in a junction point were evaluated by applying the Tanaka theory to the gel melting temperature measured by FBM. The zeta values obtained were about 40 for the quenched gel and 6 similar to 9 for the slowly cooled gel. On the other hand, the values of s were 3 for the quenched gel and 4 for the slowly cooled gel. The structure of junction point was determined by the extent of the overlapping of polymer chains in the system. Therefore, some scaling relation is expected to hold for gel melting temperature. We tried to superpose all the data points on experimentally determined master curve. The superposition was good, which showed that the scaling law held for gel melting temperature.