Interface-Dependent Mechanical Properties in MWNT-Filled Polycarbonate

Man, Yuhong; Li, Z. C.; Zhang, Z. J.

doi:10.2320/matertrans.mra2008450

Cited by 11 publications

(19 citation statements)

References 22 publications

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“…A sharp decrease in the elastic modulus to levels similar to neat PC was, however, observed with addition of 5% w/w of MWNTs and steadily declined as the MWNTs compositions increased to 20% w/w. These results are in contradiction to the findings of Man et al and Chen et al, where a monotonical increase in the elastic modulus was observed with an increase in the MWNTs even though they found a decrease in tensile strength at high MWNTs concentrations. Their study found an improvement in the elastic modulus of approximately 20% higher than that of neat PC modulus at 4–5 wt%.…”

Section: Resultscontrasting

confidence: 99%

“…Investigation of PC/CNTs composite microstructures provided very good insights. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies were very informative and supported the relationship between MWNTs loading and the composite mechanical properties . However, contradicting results on the effects of composite homogeneity on electrical conductivity were observed.…”

Section: Introductionmentioning

confidence: 91%

“…The melt mixing using a micro single screw extruder showed that a single processing cycle was insufficient to obtain homogeneous composites, and hence, no benefit in reinforcing characteristics was observed . With intense melt mixing, composite mechanical properties within the range of percolation threshold were reported to be unchanged, enhanced, or reduced . The reinforcing behaviours are understood to be a result from the breakup of CNTs agglomerates, while the decline in the mechanical properties might be due to decreased homogeneity of the composites.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Properties characterisation of polycarbonate and multi‐walled carbon nanotubes composites prepared by solution technique

Thaithae¹,

Antonio

Wattanachai

2015

Asia-Pacific J Chem Eng

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Polycarbonate (PC) and multi-walled carbon nanotubes (MWNTs) composites were prepared by solution method where 0-20% w/w MWNTs were added into two types of PC solutions, i.e. a low and a high molecular weight solution. The composites were processed into plastic sheets using a compression moulding technique in order to study their mechanical, electrical, physical, and rheological properties. The results showed that addition of MWNTs at 1% w/w enhanced the tensile strength and modulus by up to 23 and 75%, respectively, and reduced their electrical resistivity significantly from being an insulator (1 × 10 16 À 1 × 10 17 Ω-cm) to a semi-conductor (8 × 10 8 Ω-cm), indicating a percolation threshold. A slight improvement in the mechanical properties was observed at up to 4% w/w MWNTs; however, the volume resistivity remained unchanged. As the amount of MWNTs increased >4% w/w, the mechanical properties drastically deteriorated because of the MWNTs agglomerating and segregating onto the surfaces. The segregation of the agglomerates was also supported by the surface resistivity and shear viscosity results, which decreased as MWNTs increased. MWNTs were found to interact better with the low molecular weight PC matrix and produced more homogeneous composites. The studies of composite colour and MWNTs dispersion confirmed the findings of both mechanical and electrical properties. This research demonstrates the possibility of preparation of PC and MWNTs composites at high MWNTs concentrations, which can be very useful for a master batch process.

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Section: Resultscontrasting

confidence: 99%

Section: Introductionmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

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Properties characterisation of polycarbonate and multi‐walled carbon nanotubes composites prepared by solution technique

Thaithae¹,

Antonio

Wattanachai

2015

Asia-Pacific J Chem Eng

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“…This has been reported by many researchers. 22,24,35 This is also evident from images of failed MWCNT/PC composite samples ( Fig. 3(d)).…”

Section: 36mentioning

confidence: 55%

Mechanical and electrical properties of high performance MWCNT/polycarbonate composites prepared by an industrial viable twin screw extruder with back flow channel

et al. 2014

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a High performance multiwall carbon nanotube (MWCNT) reinforced polycarbonate (PC) composites were prepared using an industrially viable fast dispersion process by a micro twin screw extruder with back flow channel and their mechanical and electrical properties were investigated for EMI shielding applications. A uniformly dispersed MWCNT/PC composite system was observed through SEM and TEM investigations. Incorporation of a small amount of MWCNT (2 wt%) led to enhancements in the tensile strength (up to 79.6 MPa) and flexural strength (up to 110 MPa), which were equivalent to 19.6% and 14.6% increases over the neat PC. The effect of MWCNTs on the failure mechanism of the PC under tensile loading showed a ductile to brittle transition with increasing concentration of MWCNTs. The results of enhanced mechanical properties were well supported by micro Raman spectroscopic studies. In addition to the mechanical properties, significant improvement in the electrical conductivity (0.01 S cm À1 at 10 wt% MWCNT) of these composites was observed which yielded the EMI shielding of À27.2 dB in the Ku band suggesting their possible use as a high strength EMI shielding material.

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“…This type of a qualitative change in the stress-strain behavior with the composite becoming less ductile as CNT concentration increases has also been reported by other workers. 12,14,30 The reduced ductility of CNT/PC composites by addition of CNTs has also been reported for oriented melt-spun bers of CNT/PC composites 10,13 and for CNT/PC composites studied at cryogenic temperatures.…”

Section: Tensile Properties Of A-mwcnt/pc and F-mwcnt/pc Composite Lmsmentioning

confidence: 68%

Mechanical and electrical properties of multiwall carbon nanotube/polycarbonate composites for electrostatic discharge and electromagnetic interference shielding applications

Pande¹,

Chaudhary²,

Patel³

et al. 2014

RSC Adv.

170

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Home-made multiwall carbon nanotubes (MWCNTs) were used as a reinforcing conducting filler for a thermoplastic polymer, polycarbonate (PC) and the mechanical and electrical properties of the composites were investigated for electrostatic discharge (ESD) and electromagnetic interference (EMI) shielding applications. A uniformly dispersed MWCNT/PC composite system was fabricated using solvent casting and a combination of solvent casting and compression molding techniques. The effect of MWCNTs on the failure mechanism of the polymer under tensile loading showed a ductile to brittle transition with increasing amount of carbon nanotubes. ESD studies showed that the composite films of 2 and 5 wt% functionalized-MWCNT/PC with respective charge decay times of 1 and 0.6 s show promise as electrostatic dissipative materials. EMI shielding effectiveness of a five-layered system ($2 mm thickness) of as-synthesized-MWCNT/PC composite films at 20 wt% loading reached 43 dB in the X-band (8.2-12.4 GHz). The primary mechanism of shielding was absorption, suggesting possible use as an EMI absorbing material. By using low pressure (contact pressure) compression molding the EMI shielding properties of bulk composites ($2 mm thickness) improved by about 14 dB at 10 wt% MWCNT loading.

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Interface-Dependent Mechanical Properties in MWNT-Filled Polycarbonate

Cited by 11 publications

References 22 publications

Properties characterisation of polycarbonate and multi‐walled carbon nanotubes composites prepared by solution technique

Properties characterisation of polycarbonate and multi‐walled carbon nanotubes composites prepared by solution technique

Mechanical and electrical properties of high performance MWCNT/polycarbonate composites prepared by an industrial viable twin screw extruder with back flow channel

Mechanical and electrical properties of multiwall carbon nanotube/polycarbonate composites for electrostatic discharge and electromagnetic interference shielding applications

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