Polycarbonate reinforced with silica nanoparticles

Abstract

Nanocomposites of polycarbonate (PC) reinforced with nanosized silica particles were prepared by a melt mixing technique in an internal mixer. Two kinds of commercial hydrophilic fumed silicas differing in their specific surface area were added in amounts up to 5% by volume, and their reinforcing action was compared to that of organically modified silica, loaded in the same amounts. Particle–matrix interactions were investigated by means of rheological and dynamic-mechanical thermal analysis, demonstrating the important role played by the organic modifi- cation in the interactions with the polymer matrix, and showing an optimal nano- particle loading around 2 vol%. The scratch resistance of the nanocomposites obtained from hydrophilic silicas was investigated, and a remarkable enhancement in the indenter’s penetration resistance was observed for all the compositions with respect to pristine PC. The same behaviour was observed for the Shore D hardness and for the impact resistance of the nanocomposites that also significantly improved with the maximum load shifting from a minimum value of 521 N for pristine PC up to values grater than 1330 N for the nanocomposites, demonstrating the activation of effective mechanisms of energy dissipation due to the presence of the nanofillers

The effect of silica nanoparticles on the morphology, mechanical properties and thermal degradation kinetics of polycarbonate

“…This was related to the reduced particle-particle interactions dominated by hydrogen bonding ensued from the hydroxide groups on the silica surface and the carbonyl groups in the PC [8,11].…”

Microstructure, thermal stability, and mechanical properties of modified polycarbonate with polyolefin and silica nanoparticles

“…However, the addition of 10 wt% EPC has caused a decline in E′ of the PC; it was further improved by the addition of small amount of SiO 2 NPs. The similar trend for increasing the E ′ was observed by compounding SiO 2 NPs with the PC . In Fig.…”

The processing of polycarbonate nanocomposites generated with various nanofillers

“…They found that the composite has paramagnetic properties after adding ferrite nanoparticles to the polymer matrix: high concentrations of CoFe 2 O 4 improve the magnetic properties of the composite. PC/nanosilica (SiO 2 ) nanocomposites were prepared by a melt-blending technique (Biswal et al, 2013;Luyt et al, 2011). The behavior, however, is not linear, with the largest increases; 16% of Young's modulus and 20% of hardness were achieved on samples containing 2 wt% magnetic nanofiller.…”

“…The behavior, however, is not linear, with the largest increases; 16% of Young's modulus and 20% of hardness were achieved on samples containing 2 wt% magnetic nanofiller. Using nanosilica as a filler in PC nanocomposite, it is possible to increase the thermal stability and viscosity of the nanocomposites with respect to the pristine matrix (Luyt et al, 2011). Montaung et al (2013) prepared PC nanocomposites by melt compounding with different amounts of ZrO 2 , 1-5 wt%, and found that the amount of ZrO 2 influences the thermal degradation process.…”

“…Eitan et al (2006) studied the modification of MWCNT by chemical treatment through oxidation and then a reaction with a hydroxyl-terminated epoxy molecule. Luyt et al (2011) used a hydrophobic silica with chemically surface-bonded methy groups in polycarbonate nanocompoistes. Pötschke et al (2009) used multiwalled carbon nanotubes in the form of bucky papers modified by Ar/O 2 plasma in polycarbonate nanocomposites.…”