The Federal Polytechnic, P. M. B. 55, Department of Mechanical Engineering, Bida, Nigeria.
Federal University of Technology P. M. B. 65, Nanotechnology Research Group, Centre for Genetic Engineering and Biotechnology, Minna, Nigeria.
Sci Rep. 2019 Dec 27;9(1):20146. doi: 10.1038/s41598-019-56778-0.
This research is motivated by the desire to restore the quality of life to amputees. The study uses multi-walled carbon nanotube (WMCNT) reinforced natural rubber (NR) polymer nanocomposite (PNC) for prosthetic foot application. The compound formulation was carried out in accordance to a modified procedure described by Hemkaew et al. Mixing of the ingredients during vulcanisation was performed according to ASTM D-3182 standard on an open two-roll mill. The various compositions of the nanocomposites (NCs) were cured at a temperature of 150 ± 2 °C and a pressure of 0.2 MPa for 10 minutes in an electrically heated hydraulic press. Mechanical investigation revealed that NR/MWCNT-3 exhibited the highest capacity to withstand tensile and dynamic loading (449.79 MPa). It also showed superior filler distribution and hence improved crystallinity and cross-link. Water absorption test indicated that NR/MWCNT-3 offers optimum dimensional stability at ambient conditions. Moreover, thermogravimetric analysis/differential thermogravimetry (TGA/DTG) showed degradation peaks at 305 °C and 290 °C respectively with temperature range within which the NCs degraded lying between 250 °C and 600 °C. Dynamic mechanical analysis (DMA) revealed that filler incorporation results in higher storage and loss moduli (2000-7500 MPa and 500-1413 MPa respectively). Tan δ curves proved that NR/MWCNT-3 has the highest capacity to dissipate energy through segmental motion. Furthermore, microstructure examination confirmed good filler/matrix adhesion as NR/MWCNT-3 indicated improved interaction; hence higher strength (6.02 MPa) of the NC. Better wear resistance ability can also be reported of the newly developed than existing prosthetic material. It can be deduced that the formulated nanocomposite from MWCNTs for reinforced natural rubber is suitable for the development of the anthropomorphic prosthetic foot.
这项研究的目的是为了恢复假肢使用者的生活质量。研究采用多壁碳纳米管（MWCNT）增强天然橡胶（NR）聚合物纳米复合材料（PNC）用于义肢脚的应用。该化合物的配方是按照 Hemkaew 等人描述的改进程序进行的。在开炼机上按照 ASTM D-3182 标准进行硫化过程中的配料混合。纳米复合材料（NCs）的各种成分在 150±2°C 的温度和 0.2 MPa 的压力下，在电加热液压机中硫化 10 分钟。力学研究表明，NR/MWCNT-3 具有最高的承受拉伸和动态负载的能力（449.79 MPa）。它还显示出更好的填料分布，因此提高了结晶度和交联度。吸水性测试表明，NR/MWCNT-3 在环境条件下具有最佳的尺寸稳定性。此外，热重分析/差示热重分析（TGA/DTG）显示分别在 305°C 和 290°C 处有降解峰，NCs 降解的温度范围在 250°C 和 600°C 之间。动态力学分析（DMA）表明，填料的加入导致更高的储能和损耗模量（分别为 2000-7500 MPa 和 500-1413 MPa）。Tan δ 曲线证明，NR/MWCNT-3 通过分子链段运动具有最高的能量耗散能力。此外，微观结构检查证实了良好的填料/基体附着力，因为 NR/MWCNT-3 表明了更好的相互作用；因此 NC 的强度更高（6.02 MPa）。与现有的假肢材料相比，新开发的材料还具有更好的耐磨性。可以推断，用 MWCNTs 增强天然橡胶的配方纳米复合材料适合开发拟人义肢脚。
