Polystyrene composites containing crosslinked polystyrene‐multiwalled carbon nanotube balls
ABSTRACT Crosslinked polystyrene-multiwalled carbon nanotube (PS-MWCNT) balls, which act as conductive microfillers, were prepared by the in situ suspension polymerization of styrene with MWCNTs and divinyl benzene (DVB) as a crosslinking agent. The diameters of the synthesized crosslinked PS-MWCNT balls ranged from 10 to 100 μm and their electrical conductivity was about 7.7 × 10−3 S/cm. The morphology of the crosslinked PS-MWCNT balls was observed by scanning electron microscopy and transmission electron microscopy. The change in the chemical structure of the MWCNTs was confirmed by Raman spectroscopy and Fourier transform infrared spectroscopy. The mechanical and electrical properties of the PS/crosslinked PS-MWCNT ball composites were investigated. It was found that the tensile strength, ultimate strain, Young's modulus, and impact strength of the PS matrix were enhanced by the incorporation of the crosslinked PS-MWCNT balls. In addition, the mechanical properties of the PS/crosslinked PS-MWCNT ball composites were better than those of the PS/pristine MWCNT composites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
- J. Phys. Chem. B. 01/2004; 108:15009-15012.
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ABSTRACT: In this work, the carbon nanotubes (CNTs) were reinforced with polypropylene (PP) matrix resins to improve the electrical, thermal, and mechanical properties of CNTs/PP composites in different contents of 0, 1, 2, 3, and 5 wt.%. The volume resistivity was measured to discover the percolation threshold of the composites. The crystallization kinetics, organizations, and microstructures of CNTs/PP composites were investigated with differential scanning calorimeter (DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses, respectively. The Raman spectroscopy was also performed to obtain information on the CNTs/PP interactions. As a result, the volume resistivity was decreased with increasing the CNT content that could be governed in a percolation-like power law with a relatively low percolation threshold. And the crystallization exothermic peak shifted to a higher temperature, and the overall crystallization time was reduced by the increment of CNT content. Also, the nucleant of CNTs affected the crystallization of PP, but was not linearly dependent on the CNT content that meant a saturation of the nucleant effect at low CNT content.Materials Science and Engineering A 09/2005; 404:79-84. · 2.41 Impact Factor
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ABSTRACT: High-impact polystyrene (HIPS) was prepared by the bulk or low-solvent polymerization of styrene in the presence of dissolved rubber and characterized to measure the dispersed particle size of the rubber phase. Before preparation, the prepolymerization time was established by measuring the evolution of particle size distribution of the dispersed phase as a function of reaction time. The measurement technique by laser light scattering was found to be efficient enough not only to lead to the right prepolymerization time but also to predict rubber-phase particle size distribution. Polymerization experiments were then conducted to investigate the effect of solvent contents on the particle size distribution of the rubber phase, in which ethylbenzene was introduced as a solvent at levels of 0, 3, 10, and 15%. As the solvent content increased, the size of rubber-phase particles initially increased, reaching a maximum, and then decreased. It is speculated that a decrease in the molecular weight of the matrix, a decrease in the viscosity ratio between polybutadiene to polystyrene phases, and a change in rubber morphology all contributed to the change in the rubber particle size of HIPS. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3672–3679, 2003Journal of Applied Polymer Science 07/2003; 89(13):3672 - 3679. · 1.40 Impact Factor