Whitley J Q, Kusy R P
Dental Research Center/Department of Orthodontics and Biomedical Engineering, University of North Carolina, Chapel Hill 27599-7455.
Biomaterials. 1988 Nov;9(6):538-46. doi: 10.1016/0142-9612(88)90052-x.
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.
通过蠕变断裂试验研究了聚丙烯（PP）缝线的失效情况。从断裂时间（tB）的对数与应力（σ）的关系图中得出了线性关系。在恒定的σ下，结果表明tB与缝线直径（7-0、6-0、5-0和4-0）以及辐射剂量（0、15、20、25和50兆拉德）成反比。此外，对于6-0缝线尺寸和15兆拉德剂量，tB随温度升高（26、37、44、50和60摄氏度）而降低。对于这个蠕变断裂过程，活化能等于91.2千焦/摩尔（21.8千卡/摩尔）。提出了一种失效机制，该机制假定这些缝线是由取向的半结晶微纤维束组成。
