Functionalization Of UHMWPE And Studies Of The Morphology Structure And Properties Of PA1010/UHMWPE Blends

Grafting-copolymer of ultrahigh molecular weight polyethylene (UHMWPE) with acrylic acid (AA) was carried out by using γray radiation. FT-IR was used to characterize the formation of grafting copolymer. From FT-IR spectra, it was found that a new peak at 1716 cm-1 appeared, which is attributed to contribution of carbonyl of AA. This result verified that AA has been grafted onto the UHMWPE molecular chains.Degree of grafting of functionalized UHMWPE was measured by the chemical titration. Grafting mechanism was tentatively proposed. The effects of monomer concentration,radiation dose and radiation time on degree of grafting was studied systematically. The results showed that functionalized UHMWPE with high degree of grafting and without any gelation. Thermal properties of ultrahigh molecular weight polyethylene grafted with acrylic acid (UHMWPE-g-AA) and UHMWPE were studied by using differential scanning calorimetry (DSC).The melting enthalpy of UHMWPE-g-AA was lower than that of the neat UHMWPE. This feature could be explained as follows. Because UHMWPE grafted polar AA molecular,functionalized UHMWPE molecular chains would decrease the perfection of crystals of UHMWPE. Polyamide 1010 (PA1010)/UHMWPE-g-AA/UHMWPE alloy was prepared by using reactive extrusion method. Thermal,morphology and mechanical properties of the blends were investigated systematically. DSC analysis indicated that the crystallization of PA1010 in PA1010/UHMWPE-g-AA/UHMWPE blends was inhibited, perhaps due to chemical reaction the AA molecular in UHMWPE-g-AA and any groups in PA1010. The SEM photographs showed that domains of PA1010/UHMWPE-g-AA/UHMWPE were much smaller, and their dispersions were more homogeneous than that of the PA1010/UHMWPE blends. Mechanical properties such as elongation at break and Izod impact strength were much improved compared with that of PA1010/UHMWPE blends. But there was not much difference in their tensile strength and modulus. Frictional properties of PA1010/UHMWPE-g-AA/UHMWPE blends were higher than that of PA1010/UHMWPE blends.