title: Creep rupture of polypropylene sutures as a function of diameter, radiation dose and temperature.
abstract: The failure of polypropylene (PP) sutures was studied via creep rupture tests. Linear relationships were generated from plots of log time to break (tB) versus stress (sigma). At a constant sigma the results showed that tB was inversely proportional to the suture diameter (7-0, 6-0, 5-0 and 4-0) and to the radiation dose (0, 15, 20, 25 and 50 Mrad). Moreover, for the 6-0 suture size at a 15 Mrad dose, tB decreased with increasing temperature (26, 37, 44, 50 and 60 degrees C). For this creep rupture process the activation energy equalled 91.2 kJ/mol (21.8 kcal/mol). A mechanism for failure was presented which assumes that these sutures are bundles of oriented, semicrystalline microfibrils.
authors.affiliation: Dental Research Center/Department of Orthodontics and Biomedical Engineering, University of North Carolina, Chapel Hill 27599-7455.
authors.forename: J Q
authors.initials: JQ
authors.lastname: Whitley
authors.forename: R P
authors.initials: RP
authors.lastname: Kusy
mesh_terms: D004307:Dose-Response Relationship, Radiation; D004868:Equipment Failure; D008422:Materials Testing; D008962:Models, Theoretical; D010969:Plastics / Q000528:radiation effects; D011126:Polypropylenes / Q000528:radiation effects; D013537:Sutures; D013696:Temperature; D013718:Tensile Strength / Q000528:radiation effects
chemical_list: D010969:Plastics; D011126:Polypropylenes