Influence of lamella features of UHMWPE on its physical and uniaxial tensile properties. I. Effect of sterilization method in uncrosslinked and unaged materials
Affiliations: Department of Physics, The University of Memphis, Memphis, TN 38152, USA | Department of Physics, Rhodes College, Memphis, TN 38112, USA | Department of Mechanical Engineering, The University of Memphis, Memphis, TN 38152, USA | Department of Chemical Engineering, Christian Brothers University, Memphis, TN 38112, USA
Note: [] Corresponding author: Dr. Gladius Lewis, Department of Mechanical Engineering, The University of Memphis, Memphis, TN 38152‐3180, USA. Tel.: +901 678‐3266; Fax: +901 678‐5459; E‐mail: [email protected].
Abstract: The changes in the tensile toughness (U), degree of crystallinity (%C), melting temperature (Tm), lamella thickness, and lamella alignment of uncrosslinked and unaged GUR 1150HP ultra‐high‐molecular‐weight polyethylene specimens, following different sterilization treatments (none, γ‐irradiation in air, γ‐irradiation in a nitrogen‐rich atmosphere, ethylene oxide gas, and gas plasma) were determined. For each of the properties – U, %C, and Tm – the only significant difference in the mean value was found between the set of specimens γ‐irradiated in air, on the one hand, and each of the other sets, on the other hand. It was found that lamella thickness showed little change between the groups of specimens but there was a significant difference in the lamella orientation between the set of specimens that had been γ‐irradiated in air, on the one hand, and each of the other sets, on the other. It thus appears that the changes seen in the physical and mechanical properties determined may be a reflection of the change in the polymer's lamella alignment.
