title: Influence of lamella features of UHMWPE on its physical and uniaxial tensile properties. I. Effect of sterilization method in uncrosslinked and unaged materials.
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, gamma-irradiation in air, gamma-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 gamma-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 gamma-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.
authors.affiliation: Department of Physics, The University of Memphis, Memphis, TN 38152, USA.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Mishra
authors.forename: Ann
authors.initials: A
authors.lastname: Viano
authors.forename: Neil
authors.initials: N
authors.lastname: Fore
authors.forename: Gladius
authors.initials: G
authors.lastname: Lewis
authors.forename: Asit
authors.initials: A
authors.lastname: Ray
mesh_terms: D003460:Crystallization / Q000379:methods; D003461:Crystallography / Q000379:methods; D005027:Ethylene Oxide; D005720:Gamma Rays; D006358:Hot Temperature; D008422:Materials Testing / Q000379:methods*; D008854:Microscopy, Electron; D011095:Polyethylenes / Q000737:chemistry* / Q000528:radiation effects*; D013242:Sterilization / Q000379:methods*; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength
chemical_list: D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene; D005027:Ethylene Oxide