Drawing effect on thermal properties of high-strength polyethylene fibers

The thermal conductivity κ and thermal diffusivity α of high-strength polyethylene fibers, DyneemaTM, with various draw ratios were measured from 10 K to 260 K. κ and α increased with increasing draw ratio and α was nearly proportional to the square root of the tensile modulus E of the fiber. The estimated phonon mean free path l (40-60 angstroms) was almost temperature independent. Boundarylike scattering due to characteristic microstructures with comparable size to l may effectively limit the thermal conduction in these fibers.