In-situ preparation and characterization of ultra-high molecular weight polyethylene/diamond nanocomposites using Bi-supported Ziegler-Natta catalyst

In this study, reinforcement of ultra-high molecular weight polyethylene (UHMWPE) was investigated using the sol-gel surface modified diamond nanoparticles (NDs). Nanocomposite samples were synthesized via in-situ polymerization using bi-supported Ziegler-Natta catalyst. Fourier transform infrared spectroscopy, thermogravimetric analysis and contact angle measurements proved the proper silanization (∼1.9%) of NDs. Characterization of the catalysts revealed decrease in the activity of catalysts in presence of NDs which were responsible for the lower average molecular weight of the samples. Field emission scanning electron microscopy revealed an improved dispersion of the modified NDs in UHMWPE matrix by silanization. The incorporation of 2 wt.% unmodified and modified NDs enhanced the storage modulus (≤106% and ≤124%) and tensile strength (≤33% and ≤86%), respectively. Also, improvement in shore D and scratch hardness strength can be achieved in presence of NDs. Furthermore, tribological properties of the samples were investigated and discussed accordingly.