Lewis G, Xu J, Madigan S, Towler M R
Department of Mechanical Engineering, The University of Memphis, Memphis, TN 38152-3180, USA.
J Mater Sci Mater Med. 2007 Aug;18(8):1649-58. doi: 10.1007/s10856-007-3042-5. Epub 2007 May 5.
This study is a contribution to the growing body of work on the influence of changes in the composition of an acrylic bone cement on various properties of the curing and cured material. The focus is on one commercially-available acrylic bone cement brand, Surgical Simplex P, and three variants of it and a series of properties, namely, setting time, maximum exotherm temperature, activation energy and frequency factor for the polymerization reaction, diffusion coefficient for the uptake of phosphate buffered saline, at 37 degrees C, ultimate compressive strength (UCS), plane-strain fracture toughness, fatigue life (under fully-reversed tension-compression stress), hardness (H) and elastic modulus (both determined using quasi-static nanoindentation), and the variation of the storage and loss moduli with frequency of the applied force in a dynamic nanoindentation test. It was found that (a) a 68% reduction in the volume of the activator, N,N dimethyl-4-toluidine, relative to the total volume of the liquid monomer (the amounts of all the constituents in the powder and of the hydroquinone in the liquid monomer remaining unchanged) led to, for example, a significant decrease in the rate of the polymerization reaction, at 37 degrees C (c') and a significant increase in H; and (b) the elimination of the pre-polymerized poly (methyl methacrylate) beads in the powder (the amounts of all the other powder constituents and those of the liquid monomer remaining unchanged) led to, for example, a significant drop in c' and a significant increase in UCS. Thus, these findings suggest a strategy for optimizing the composition of an acrylic bone cement.
本研究为正在不断增加的关于丙烯酸骨水泥成分变化对固化及固化后材料各种性能影响的研究工作做出了贡献。研究重点是一种市售丙烯酸骨水泥品牌Surgical Simplex P及其三种变体，以及一系列性能，即凝固时间、最大放热温度、聚合反应的活化能和频率因子、37℃时磷酸盐缓冲盐水吸收的扩散系数、极限抗压强度（UCS）、平面应变断裂韧性、疲劳寿命（在完全反向拉压应力下）、硬度（H）和弹性模量（均使用准静态纳米压痕测定），以及动态纳米压痕试验中储能模量和损耗模量随施加力频率的变化。研究发现：（a）相对于液体单体总体积，活化剂N,N-二甲基-4-甲苯胺的体积减少68%（粉末中所有成分的量以及液体单体中对苯二酚的量保持不变），例如导致37℃时聚合反应速率显著降低（c'）以及H显著增加；（b）粉末中预聚合聚甲基丙烯酸甲酯珠粒的去除（所有其他粉末成分的量以及液体单体的量保持不变），例如导致c'显著下降以及UCS显著增加。因此，这些发现为优化丙烯酸骨水泥的成分提供了一种策略。
