Influence of Vitamin C on Morphological and Thermal Behaviour of Biomedical UHMWPE

Abstract

Summary: Biomedical Ultra-High-Molecular-Weight Polyethylene (B-UHMWPE) is widely used in orthopaedics as a biomaterial because of its mechanical properties and biocompatibility. However the adding of vitamin antioxidants can influence the inflammatory process. Thus, the objective of this study is to evaluate the influence of adding ascorbic acid (vitamin C) at different concentrations to the B-UHMWPE matrix, using for this purpose the Scanning Electron Microscopy (SEM) and Differential Scanning Calorimetry (DSC) analyses. The vitamin C was mixed with B-UHMWPE in concentrations of 0.5, 1.0 and 2.0%wt and the molding was performed with a 10MPa load at 160 C for 6min.The fracture surface of cross-sectional area of B-UHMWPE modified with vitamin C showed that the vitamin is present in the polymer matrix in the form of small agglomerates, being an indication that there was no fusion of the vitamin C during the processing step. Using the technique of differential scanning calorimetry it was observed that the melting temperature remained constant as well as the crystallisation temperature, but there was a small variation in crystallinity with the addition of vitamin C. From this study, we conclude that the presence of vitamin C (ascorbic acid) did not alter the thermal properties of crystallisation and melting of B-UHMWPE.

Antioxidant Effects of Vitamin C on Biomedical UHMWPE Compounds

“…Table 3 presents the degree of crystallinity for the pure polymer and compounds with Vitamin C, compared to values obtained using differential exploratory calorimetry (DSC), as used in a previous study. [3] Using Raman, the crystallinity values obtained were lower than those obtained using DSC. The differences for B-UHMWPE and its compounds using DSC technique were not significant.…”

“…We may calculate the degree of crystallinity of the samples from deconvolutions of the bands present in these regions using Equation . Table presents the degree of crystallinity for the pure polymer and compounds with Vitamin C, compared to values obtained using differential exploratory calorimetry (DSC), as used in a previous study . Using Raman, the crystallinity values obtained were lower than those obtained using DSC.…”

“…a) crystallinity using Raman; b) crystallinity usingDSC. [3] Macromolecular Symposia www.advancedsciencenews.com www.ms-journal.de…”

“…The wear of such biomaterials in the human body is the main reason for prosthesis exchange surgeries, and thus, increases in the useful life of prostheses are much sought after. Certain authors, aiming to increase resistance to surface wear have modified UHMWPE surfaces by means of ionizing radiation, which leads to formation of crosslinks. The radiation process unleashes oxidation and leads to the formation of free radicals in the polymer.…”

Non-isothermal crystallization kinetics of UHMWPE composites filled by oligomer-modified CaCO3

“…In comparison with other polyethylene, UHMWPE has lower coefficient of friction [5][6][7], higher mechanical strength [8,9] and abrasion resistance [10][11][12]. Thus, UHMWPE has a wider foreground of application for pipeline industry [13,14], biological medicine [15][16][17], textile industry [18,19] and so on. Nevertheless, UHMWPE has extremely high molecular weight so that it is difficult to be processed by common processing method.…”