Evolution of crystalline orientation and texture during solid phase die‐drawing of PP‐Talc composites

Abstract

The objective of the present work was to examine the development of crystalline orientation and texture in the polypropylene matrix of talc-filled i-PP and in unfilled i-PP with increasing draw ratio during solid-phase die-drawing at high strain rates (1 s 21 ) and a die temperature of 145 C. After drawing, the entire billet was cooled rapidly "under tension" to room temperature before releasing the billet and cutting specimens from different axial locations for analysis. Orientation distributions of the three crystal axes for increasing axial strains have been presented as pole figures in the MD-TD plane with the direction of draw (MD) as the reference direction. While disruption of spherulites was noticed within the die for neat PP at a draw ratio of 1.5, transcrystalline domains within the composite persisted even at a draw ratio of 3.5 in the free draw region outside the die. The transformation to fibrillar crystal morphology was complete in both materials at a draw ratio of 4.5 but the texture continued to develop beyond this stage. While the (110)[001] texture component was found to be dominant at all draw ratios for neat PP, the (010)[001] texture component was dominant at the higher draw ratios in the drawn composite. This may be attributed to the (010)[001] slip system being more active as the transverse spacing between elongated voids encasing the particles was decreased.

Effect of filler content, size, aspect ratio and morphology on thermal, morphological and permeability properties of porous talc filled—Polypropylene obtained throughMEAUSprocess

“…It is assumed that one of these peaks corresponds to crystals of the interconnected bridges between the lamellae and the other reflects the lamellae crystals. [28][29][30] Seguela et al [31] they reported the transition of metastable phase to more stable a-PP crystals during deformation process. They also showed that this endotherm revealed a smectic metastable phase, which was produced when a polypropylene film was extruded and rapidly cooled to room temperature.…”

Blown films with balanced in-plane properties from polypropylene-clay nanocomposites though silane coupling

“…The applied voltage and amperage of the X-ray beam was selected to make sure it penetrated through the polypropylene film. 19 The incident beam was collimated by a 1 mm diameter collimator. The film samples were subjected to azimuthal scans with the detector positioned at 2h angles of the a(110), a(040) and a(130) crystal planes of polypropylene.…”

Effect of Drawing Parameters on the Properties of Polypropylene/Inorganic Particles Composites by Solid-State Die Drawing

“…The results of many studies have shown that composite material after inorganic filling had obvious mechanical performance improvement under the combined action of the drawing load at the free end [29,30]. Wu et al [31] studied the properties of PP/multi-wall carbon nanotube composites under the die drawing method and showed that the tensile strength increased by 550% after drawing.…”

“…Lin et al [32] investigated the performance of porous tape prepared by solid-state drawn PP/Talc composites, and the results showed that the porosity increased with the increase in the drawing ratio. Rane et al [30] studied the crystal orientation and microstructure development of PP/Talc composites under different tensile ratios. As far as the current research is concerned, there are few studies on the effect of drawing process parameters on the properties of PP/inorganic particle composites.…”