Crystal structure of single-crystalline high-density polyethylene in solution

Abstract The crystal lattices of high-density polyethylene (HDPE) single crystals in the solution state and dry state were investigated using wide-angle X-ray diffraction (WAXD) and infrared spectroscopy. WAXD measurement revealed that the size and ordering of the crystal lattice of the HDPE single crystals decreased after the drying process of the solvent. The HDPE single crystals in the solution state possess a precise crystal lattice that cannot be seen in the dry state. This indicates that the crystal lattice of the HDPE single crystals cannot be maintained during the drying process. The thermal lattice expansion of HDPE single crystals in the solution state was more pronounced than that in the dry state because of the restrictive effects of cohesive forces in the latter case. The obtained insights shed light on the underexplored structure and properties of isolated HDPE single crystals in solution and may therefore advance the basic science of polymer crystals.