Fiber reinforced polyketone and polyketone/polyamide 6 composite production

In this thesis, 30% glass fiber reinforced polyketone (PK) and polyketone/polyamide 6 (PK-PA6) blends were prepared homogeneously using a twin screw extruder. PK terpolymer with two different MFI (Melt flow index) values and a PA-6 were used in the blends. The PK and PK/PA-6 composites were prepared with two types of E-glass fibers added at an amount of 30 wt %. The 534A-type fibers were treated with a silane-based sizing, compatible with poly(ethylene terephthalate) and poly(butylene terephthalate) and the 568H-type fibers (were treated with a silane-based sizing, compatible with PA-6 and PA-66. This process was preferred to increase compatibility at the fiber-matrix interface and improve the mechanical properties of the composite material. The ethylene terpolymer (C1) and maleic anhydride grafted polyethylene (C2) were used as compatibilizers, while zinc stearate was used as a lubricant. The impact of two compatibilizers, ethylene terpolymer (C1) and maleic anhydride grafted polyethylene (C2), on the mechanical, thermal, and tribological properties of 30% glass-fiber-reinforced polyketone (PK) and polyketone/polyamide 6 (PK/PA-6) blend composites was investigated. In the case of 30% glass-fiber reinforced PK composites, the mechanical test results showed that C2 significantly improves the impact resistance (over 48.8%) and elongation at break (over 13.3%) values due to the enhanced compatibility between glass fibers and the PK matrix, attributed to the maleic anhydride functionality. The tensile and flexural properties of the 30% glass-fiber reinforced PK/PA-6 blend composites were determined to be between the values of pure PK/GF30 and PA-6/GF30 composites, which were its constituent components. Notably, these blend composites displayed higher impact resistance (19.6 kJ/m²) and elongation at break (4.86%) values than the pure PK/GF30 and PA-6/GF30 composites. The SEM images suggested that C2 creates a better interface between glass fibers and the matrix, resulting in a more cohesive structure. Differential scanning calorimeter analysis revealed two distinct glass transition temperatures, indicating the existence of two phases, and reflecting the immiscibility of the two polymers. Tribological studies showed that the friction coefficients and specific wear rates of PK/PA-6/GF30 composites were improved by increasing PK segment. The PK-25/PA6-50/GF30-C2 sample exhibited a friction coefficient of 0.341 μ and a specific wear rate of 1.15 10¯6 mm3/Nm. Overall, the C2 proved to be a more suitable compatibilizer than C1, offering valuable insights for tailoring high-performance materials with enhanced properties.