title: The use of trans-vinylene formation in quantifying the spatial distribution of electron beam penetration in polyethylene. Single-sided, double-sided and shielded irradiation.
abstract: The use of the quantification of trans-vinylene unsaturations in irradiated ultrahigh molecular weight polyethylene (UHMWPE) in determining the spatial distribution of electron beam penetration was investigated. UHMWPE was irradiated with a 10MeV linear electron beam accelerator to 100kGy at both room temperature and 125 degrees C in air. The irradiation was carried out in shielded and unshielded single-sided and unshielded double-sided irradiation modes. Dose-depth profiles were measured by quantifying the yields of trans-vinylene unsaturations as a function of depth away from the e-beam incidence surfaces using infrared spectroscopy. The extent of beam penetration increased with increasing irradiation temperature as was manifested by the increase in the iso-dose penetration with the unshielded single-sided irradiation and increased dose overlap with the unshielded double-sided irradiation. The optimum thickness with maximum uniformity in dose-depth distribution for double-sided irradiation was 85 and 90mm for 25 degrees C and 125 degrees C irradiation temperatures, respectively.
authors.affiliation: Orthopaedic Biomechanics and Biomaterials Laboratory, Massachusetts General Hospital, GRJ, 1206 55 Fruit Street, Boston, MA 02114, USA. orhun@alum.mit.edu
authors.forename: Orhun K
authors.initials: OK
authors.lastname: Muratoglu
authors.forename: John
authors.initials: J
authors.lastname: Delaney
authors.forename: Daniel O
authors.initials: DO
authors.lastname: O'Connor
authors.forename: William H
authors.initials: WH
authors.lastname: Harris
mesh_terms: D001672:Biocompatible Materials / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004583:Electrons; D010315:Particle Accelerators; D020959:Polyethylene / Q000737:chemistry*; D011095:Polyethylenes / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013696:Temperature; D013718:Tensile Strength
chemical_list: D001672:Biocompatible Materials; D011095:Polyethylenes; D011145:Polyvinyls; C111601:ultra-high molecular weight polyethylene; D020959:Polyethylene