Effects of olefin-based compatibilizers on the morphology, thermal and mechanical properties of ABS/polyamide-6 blends

The Influence of Fused Deposition Modeling Parameters on the Properties of PA6/PA66 Composite Specimens by the Taguchi Method and Analysis of Variance

Fused deposition modeling (FDM) is widely used in the rapid prototyping of polymers. Polyamide (PA) has excellent mechanical properties, but its application in FDM is limited due to its high water absorption, warpage, and forming shrinkage. The material of the filament and the printing parameters of the printer are two critical aspects that affect the performance of a component. The prepared PA6/PA66 (composite polyamide [COPA], PA6:PA66 = 85:15) composite (COPA: acrylonitrile butadiene styrene [ABS]: maleic anhydride grafted acrylonitrile butadiene styrene [ABS-g-MAH]: polyethylene = 800:133:67:100) has low water absorption (0.39%) and high dimensional stability, which has a good application prospect in FDM. The influence of eight FDM parameters, including three rarely reported, on the properties of PA6/PA66 composite specimens was investigated by the Taguchi method. The significance of influencing factors was evaluated by analysis of variance (ANOVA) and the stability by signal-noise ratio. When the layer thickness was 0.15 mm, the infill pattern was zigzags, the build plate adhesion type was brim, and the distance from the nozzle to the printing platform and the layer thickness (ΔL) was 0.05 mm; the specimens' dimensional accuracy, surface quality, and mechanical properties were better than other levels. The layer thickness and infill pattern were the two most important factors. The switch of the cooling fan and the temperature printing platform played a significant role in the specimens' dimensional accuracy and surface quality. ΔL tremendously influenced the thickness and warping degree of the specimens. The preparation of high-performance PA composites and the investigation of multiparameters by the Taguchi method provide a possible solution for applying polyamide in FDM.

Investigation of rheological behavior of polyamide 6/acrylonitrile–butadiene–styrene/nanoclay in transient shear flow

Linear and nonlinear (in both steady and transient shear flows) rheological properties of polyamide 6/acrylonitrile–butadiene–styrene (PA6/ABS) nanocomposite blends have been investigated. Characterization of nanocomposite samples morphology by scanning electron microscopy revealed that with increasing nanoclay loading, size of dispersing phase droplets decreases significantly and their uniformity improved considerably. Transmission electron microscopy observations clearly display a coexistence of intercalate and exfoliate structure for nanoclay in the polymer-blend nanocomposite. On the other hand, we see that the tactoids are collected of a few silicate layers and possibly also of a single silicate. In other words, the results on rheological properties indicated that overshoots were observed for the start-up tests after different shear rates and delay times. Also, the results showed that the height of these overshoots increased with the applied shear rate and delay time. In addition, the overshoots are highly dependent on the network structure of the blends, and the magnitude of the overshoots increases with increasing nanoclay content. Hence, at very short delay time, the transient shear viscosity does not display any overshoot, while with increment in the delay time, the overshoot appears and increases as the delay time increases. Presented results revealed that increment in the preshearing rate decreases elastic and increases viscose behavior of nanocomposite samples.

Largely enhanced fracture toughness of an immiscible polyamide 6/acrylonitrile–butadiene–styrene blend achieved by adding chemically modified graphene oxide

Schematic showing of dual effect of PS–GO with PA6 and ABS components.