| Popis: |
The nanocomposites between polyamide 11 and functionalized graphene nanoplatelets (GNPs); graphene carboxylic acid (GCOOH) was prepared to study the effect of GCOOH content and to study the effect of chill-roll velocity via cast film extruder on electrical, mechanical, thermal properties and morphology of nanocomposites. The nanocomposites were compounded with the different GCOOH weight ratio at 0, 0.5, 1.0, 2.0 and 4.0 wt% via a twin-screw extruder and a cast film extruder into films with the chill-roll velocities of 1.0, 1.3, 1.6 and 1.9 m/min. The film thickness was about 160-450 micron. The surface electrical resistivity of the composite films with a GCOOH concentration higher than 2 wt% had lower value compared to the neat PA11, and the values were reduced with the higher chill-roll velocity. SEM micrographs indicated the PA11 fracture surface was rougher than that of PA11/GC which adding higher GCOOH concentration showed smooth fractured surface because of brittleness. The failure occurred at the interphase between PA11 and GCOOH. GCOOH acted as a nucleating agent which the crystallization temperature was shifted to higher temperature compared to the neat PA11. Tensile stress at elongation 400% of the PA11/GCOOH films tended to be higher with the increasing chill-roll velocity. |
