Delamination of Organically Modified Layered Filler via Solid‐State Processing

Abstract

Summary: Solid‐state processing for the preparation of poly(p‐phenylenesulfide) (PPS‐) based nano‐composites having finely dispersed layered fillers was conducted. The mixture of PPS and organically modified layered filler (OMLF) (95/5 wt./wt.) was subjected to the processing using thermostated hot‐press at 150 °C, below Tm of PPS (i.e., PPS is still at the solid‐state), and applying pressures of 33 MPa for 30 s. The mixture exhibited disorder and delaminated layer structure with the thickness of 10–20 nm into the PPS matrix. In contrast, a nano‐composite prepared by melt compounding at 300 °C for 3 min showed large stacked silicate layers in the PPS matrix. The processing led to delamination of the silicate layers and attained the discrete dispersion.

The Influence of the Clay Particles on the Mechanical Properties and Fracture Behavior of PLA/o‐MMT Composite Films

“…The previous results seem to indicate that the mechanism for organoclay dispersion and exfoliation during the melt‐extrusion process was not so effective when the PLA was mixed with o‐MMT. It is well known that shear stress during the melt extrusion favors the breakup of large organoclay particles into dispersed stacks before individual platelets peel apart, which happens after delamination of the layered stacks . The values of ℓ p and ℓ p / t p presented in this work (Table ) suggest that breakup of silicate tactoids as well as some diffusion of polymer chains between sandwiched platelets occur with an inefficient delamination process and poor exfoliation.…”

Dispersion and Major Property Enhancements in Polymer/Multiwall Carbon Nanotube Nanocomposites via Solid-State Shear Pulverization Followed by Melt Mixing

“…Introduction. Intense research has been focused on polymer nanocomposites because of their potential to dramatically enhance properties relative to neat polymer and to yield multifunctional materials. – Since their discovery in the early 1990s, carbon nanotubes (CNTs) have been extensively studied as nanofillers – because of their low density, high aspect ratio, and excellent mechanical, electrical, and thermal properties. However, major challenges remain in polymer/CNT nanocomposites, especially related to CNT dispersion via industrially scalable, environmentally friendly methods and understanding the relationship between dispersion and optimal properties.…”

“…26,27 Limited, related effects have been observed with batch, solid-state processing. 25,32,[44][45][46] In particular, using a solventless, two-step SSSP-plus-MM process, we show that heavily entangled, unmodified MWCNTs can be well dispersed in polypropylene (PP). We achieve 50-57% increases in Young's modulus, the largest improvement in Young's modulus ever reported for unoriented, isotactic PP/ MWCNT nanocomposites.…”

Morphological evolution of block copolymer nanocomposites submitted to extensional flows

“…Whether block copolymers are used for their mechanical or electrical properties, there is a need to control their morphology [17]. In the case of a block copolymer with a certain chemical structure and molecular weight, this control can be achieved during processing and through the addition of well-tailored nanoparticles [18][19][20][21][22]. In particular, the morphology of block copolymers can be controlled by subjecting them to shear or extensional flows.…”