Solid state features and mechanical properties of PEI/PBT blends

Abstract

Extrusion-blended and injection-molded PEI/PBT blends were found to be miscible whatever the composition. The processability of the blends clearly improved with the presence of PBT. The melt pressure at the exit was seen to be a parameter as representative of the processability of the blends as the torque of blending. In the blends with 80 and 90% PBT, a positive volume of mixing and the maintenance of the crystallinity of PBT were seen. However, in the rest of the blends, negative volumes of mixing and important decreases in the crystallinity of PBT were found. These solid state features gave rise to a ductility similar to that of the pure PEI and to a synergism of the modulus of elasticity and of the yield stress in the 90/10 and 80/20 blends such that the values were higher than those of either of the pure components.

Widely dispersed PEI-based nanocomposites with multi-wall carbon nanotubes by blending with a masterbatch

“…A single T g peak appeared for each PN at temperatures between the T g of PEI and that of the PBT indicating a single miscibilized amorphous phase. This was to be expected because of the miscibility of PEI/ PBT blends [15]. These T g values are shown (continuous line) against the MWCNT content in Fig.…”

“…The melt conditions of the extruder are close to those of practical conditions. It has been also observed [15] that P provides similar results to the torque measurements obtained in a discontinuous kneader. P is a parameter directly related to melt viscosity, and thus, is a good indicator of the processability of the PNs.…”

“…This shows a significant improvement in the processability of PEI after the addition of the master-batch. As PBT clearly reduces P in PEI/PBT blends [15], the improvement in processability of the PEI-based PNs is attributed to the presence of the low-viscosity PBT in the masterbatch.…”

“…PEI is known to be fully miscible with poly(butylene terephthalate) (PBT) throughout the entire composition range [15]. Moreover, well-dispersed PBT-MWCNT master-batches are commercially available.…”

Thermal and mechanical properties of TPU/PBT reinforced by carbon fiber

“…Melt Flow Index (MFI) can be used to indicate the melt viscosity of polymers and is also an important parameter to indicate the engineering performance of polymer [21,22] . MFI values of each sample are shown in FIGURE 2.…”