Effect of maleic anhydride-grafted polytetrafluoroethylene on the tensile and tribological properties of blending polytetrafluoroethylene with polyamide-6

摘要

Blending polytetrafluoroethylene (PTFE) to polyamide-6 (PA6) with and without maleic anhydride-grafted polytetrafluoroethylene (PTFE-g-MA) was produced in a corotating twin screw extruder, where PTFE acts as the polymer matrix and PA6 as the dispersed phase. The effect of PTFE-g-MA on the tensile properties and tribological properties of PTFE/PA6 polymer blends is studied. Results show that the structural stability and morphology of the blends were greatly improved by PTFE-g-PA6 grafted copolymers, which were formed by the in situ reaction of anhydride groups with the amino end groups of PA6 during reactive extrusion forming an imidic linkage. The presence of PTFE-g-PA6 in the PTFE continuous phase improves the interfacial adhesion, as a result of the creation of an interphase that was formed by the interaction between the formed PTFE-g-PA6 copolymer in situ and both phases. Compared with the PTFE/PA6 without PTFE-g-MA, the PTFE/PA6 with PTFE-g-MAhad the lowest friction coefficient and wear under given applied load and reciprocating sliding frequency. The interfacial compatibility of the composite prevented the rubbing-off of PA6, accordingly improved the friction and wear properties of the composite.