Multiwalled carbon nanotubes incorporated into a miscible blend of poly(phenylenether)/polystyrene – Processing and characterization

Abstract

Abstract. 4 wt% multiwalled carbon nanotubes (MWCNTs) were incorporated into a miscible blend of polyphenylenether/ polystyrene (PPE/PS) on a twin-screw extruder at a screw speed of 600 rpm. The masterbatch obtained was diluted at 400 and 600 rpm to obtain lower MWCNT loadings in PPE/PS. Electron microscopy & optical microscopy images show very good MWCNT dispersion even at high filler loadings of 4!wt%, but slightly larger agglomerate size fractions are observable at higher screw speeds. While MWCNT addition enhanced the thermal stability of PPE/PS, a small change in glass transition was observed on the composites at different filler concentrations compared to PPE/PS. The specific heat capacity at glass transition decreases considerably until 2!wt% MWCNT and levels down thereafter for both processing conditions pointing to enhanced filler-matrix interaction at lower loadings. Storage modulus of the nanocomposites was enhanced significantly on MWCNT incorporation with reinforcing effect dropping considerably as a function of temperature, especially at lower filler contents. The modulus and the tensile strength of PPE/PS were only marginally enhanced in spite of excellent MWCNT dispersion in the matrix. Electrical percolation occurs at 0.4!wt% MWCNT content, and the electrical conductivity of 0.5!wt% MWCNT reinforced PPE/PS was close to 12 orders in magnitude higher compared to PPE/PS.

Thermoplastic Nanocomposites with Carbon Nanotubes

“…Side feeding of the filler Nanocyl TM NC7000 which has a lower agglomerate strength is recommended owing to its loosely packed agglomerate structure with better dispersion envisioned by a dominant melt infiltration [84]. We have carried out comprehensive investigations on the influence of the twinscrew process parameters on MWCNT dispersion in PP, PS, PPE/PS and PC and have understood that the ideal processing parameters is strongly dependant on the nature of the matrix and its compatibility with the CNTs [65][66][67]83]. …”

An Image-Based Method for Objectively Assessing Injection Moulded Plastic Quality

“…Especially mould temperature and packing pressure are identified by Piscotti et al to have a high impact on color and gloss. Inhomogeneity in color across the material surface is often caused by insufficient dispersion of fillers or colorants, or by injection moulding parameters too [8,7].…”

Role of nanosilica localization on morphology development of HDPE/PS/PMMA immiscible ternary blends

“…This is why a considerable number of studies have been directed toward understanding parameters controlling the nanoparticle localization in polymer blends. It has been shown that the nanoparticle localization can be determined by thermodynamic parameters and more specifically by interfacial interaction between the nanoparticles and blend components or kinetic parameters, including the feeding sequence, viscosity of the blend components and mixing conditions [22][23][24]. It has been shown that the particle-particle and particle-polymer interactions have a major impact on the rheological as well as mechanical enhancement of fumed silica-filled nanocomposites due to the large surface area of particles.…”