The Effect of Phase Structure on the Tribological Properties of PA66/HDPE Blends

Abstract

Summary: In this paper, immiscible, partially miscible and miscible blends of polyamide 66 (PA66) and high density polyethylene (HDPE) were obtained by changing compatibilizer concentrations. Mechanical and tribological properties of materials were tested. It was found that the addition of compatibilizer greatly improved the mechanical properties of PA66/HDPE blends. The wear of PA66/HDPE blends was strongly affected by the phase structure. The best blend for lower friction coefficient and higher wear resistance was the blend with a miscible structure, which significantly improved the tribological properties of PA66 and HDPE. SEM investigations on the worn surface and the steel counterface indicated that, for the immiscible and partially miscible blend systems, the dispersed HDPE particles were pulled out from the worn surfaces during sliding because of the poor adhesion between HDPE and PA66, while this was not observed in the miscible blend system.

The effect of zinc oxide addition on the compatibilization efficiency of maleic anhydride grafted high‐density polyethylene compatibilizer for high‐density polyethylene/polyamide 6 blends

“…Examinations of these micrographs, as well as dispersed phase sizes determined from these micrographs ( Table II), indicate that, based on this measure of blend compatibility, at least 2.5% of the compatibilizing agent is required to achieve maximum compatibilization efficiency. The amount of compatibilizer required for maximum efficiency is substantially higher than that found previously for HDPE/PA66 with HDPE-g-MAH compatibilizer, 28 as well as ethylene-acid copolymer and copolymer ionomer compatibilizers for blends between PA6 and LDPE. 35,37 Table II also indicates that the addition of zinc oxide causes slightly larger dispersed phase size at a given compatibilizer concentration.…”

“…The percentage increase in tensile strength versus the uncompatibilized material is $ 25%, which is significantly higher than the approximate 15% found for the HDPE-g-MAH compatibilizer in HDPE/PA 66 blends at a 25/75 weight fraction. 28 However, this value is substantially smaller than the $ 50% found in HDPE/PA 6 blends for compatibilizers such as ethylene-vinyl acetate 24 or an ethylene-methacrylic acid-isobutyl acrylate terpoly- mer zinc ionomer. 12 The tensile strength in the HDPE/PA6 20/80 blend is only 20% lower than a simple mixing rule prediction using pure material properties.…”

“…A small amount ($ 1%) is required for the maximum improvement in room temperature mechanical properties and maximum reduction in dispersed phase size. Adding more than this amount does not, in general, improve performance, 10,22,28 although higher levels of compatibilizer were found to be necessary in certain cases. 27 2.…”

“…27 2. Some studies investigated changes in room temperature mechanical properties with compatibilization 22,25,27,28 ; however, some studies were interested primarily in rheological behavior. 27,29,30,33 The addition of compatibilizer raises G 0 at low frequencies, 29 reduces the interfacial tension, 11 and increases the steady-shear melt viscosity.…”

Effect of compatibilizer on the transfer and tribological behaviors of PA46/HDPE polyblends

“…Bahadur and co-author [16] added some compatibilizers to the polyblends, and found that the compatibilizer did not influence the tribological properties, although it obviously changed the phase structure and mechanical properties of the polyblends. Study in our lab [17] showed that phase structure also affected the tribological properties of the polyblends. Better miscibility of the components of polyblend associated with a lower friction and wear.…”