STUDY OF POLYOLEFIN GEL IN ORGANIC-SOLVENTS .2. STRUCTURE AND MORPHOLOGY OF BRANCHED LOW-DENSITY POLYETHYLENE GEL IN ORGANIC-SOLVENTS

Two kinds of branched low density polyethylene (BLDPE) gels were prepared by cooling a solution rapidly (a rapid cooling gel) and slowly (a slow cooling gel), and the morphology as well as the structure of the gels were studied. Moreover, gel-melting temperature T//m**g was measured and its dependence on polymer concentration, molecular weight, and branching degree was also investigated. A range of weight-average molecular weight of samples used is from 8. 7 multiplied by 10**4 to 17. 5 multiplied by 10**4. For both rapid and slow cooling gels, T//m**g increases with increasing polymer concentration as well as molecular weight, but decreases with increasing branching degree. The minimum polymer concentration C* for gel formation and the form of crystallites in gels depend on the cooling rate of a solution considerably, though the difference in T//m**g between the rapid cooling gel and the slow cooling one for a same sample is little.