Mechanical Dispersion and Molecular Motion in Crystals of Polyethylene and Other Polymers

摘要: Dynamic mechanical loss of solution-grown polyethylene crystals is measured by the suspension method as a function temperature and crystalline dispersion (α dispersion) observed above 40°C in just same manner melt-grown polyethylene. In range this dispersion, ratio crystal lattice constants b/a progressively changes toward that higher symmetry hexagonal form with increasing temperature. NMR line width broad component becomes gradually narrow rising range. It concluded from these reasons α should be ascribed to rotational vibration chain molecules phase about c-axis. Similar behavior low molecular weight paraffin below transition point affords an additional confirmation conclusion. Crystalline dispersions other polymers are briefly discussed.