Mechanical properties and biocompatibility of melt processed, self-reinforced ultrahigh molecular weight polyethylene.
The low efficiency of fabrication of ultrahigh molecular weight polyethylene (UHMWPE)-based artificial knee joint implants is a bottleneck problem because of its extremely high melt viscosity. We prepared melt processable UHMWPE (MP-UHMWPE) by addition of 9.8 wt% ultralow molecular weight polyethylene (ULMWPE) as a flow accelerator. More importantly, an intense shear flow was applied during injection molding of MP-UHMWPE, which on one hand, promoted the self-diffusion of UHMWPE chains, thus effectively reducing the structural defects; on the other hand, increased the overall crystallinity and induced the formation of self-reinforcing superstructure, i.e., interlocked shish-kebabs and oriented lamellae. Aside from the good biocompatibility, and the superior fatigue and wear resistance to the compression-molded UHMWPE, the injection-molded MP-UHMWPE exhibits a noteworthy enhancement in tensile properties and impact strength, where the yield strength increases to 46.3 ± 4.4 MPa with an increment of 128.0%, the ultimate tensile strength and Young's modulus rise remarkably up to 65.5 ± 5.0 MPa and 1248.7 ± 45.3 MPa, respectively, and the impact strength reaches 90.6 kJ/m(2). These results suggested such melt processed and self-reinforced UHMWPE parts hold a great application promise for use of knee joint implants, particularly for younger and more active patients. Our work sets up a new method to fabricate high-performance UHMWPE implants by tailoring the superstructure during thermoplastic processing.
State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering and, Sichuan University, Chengdu 610065, People's Republic of China.
Yan-Fei
YF
Huang
State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering and, Sichuan University, Chengdu 610065, People's Republic of China.
Jia-Zhuang
JZ
Xu
Department of Biomedical Engineering, College of Polymer Science and Engineering and, Sichuan University, Chengdu 610065, People's Republic of China.
Jian-Shu
JS
Li
Rehabilitation Centre, Sport Hospital Attached to Chengdu Sport University, 251 Wuhou Temple Street, Chengdu 610041, People's Republic of China.
Ben-Xiang
BX
He
State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering and, Sichuan University, Chengdu 610065, People's Republic of China. Electronic address: xulingshannon@gmail.com.
Ling
L
Xu
State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering and, Sichuan University, Chengdu 610065, People's Republic of China. Electronic address: zmli@scu.edu.cn.
Zhong-Ming
ZM
Li
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D007720:Knee Prosthesis; D055595:Mechanical Phenomena; D051379:Mice; D011095:Polyethylenes / Q000737:chemistry*; D013499:Surface Properties; D013718:Tensile Strength / Q000502:physiology; D014961:X-Ray Diffraction
D001672:Biocompatible Materials; D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene
Artificial joints; Flow accelerator; Melt processing; Self-reinforcement; Ultrahigh molecular weight polyethylene