Jiachun Zhong

Synergetic effect of cyanogen functionalized carbon nanotube and graphene on the mechanical and thermal properties of poly (arylene ether nitrile)

Cyanogen functionalized carbon nanotube and graphene/poly (arylene ether nitrile) (CNT-CN/GN-CN/PEN) nanocomposite films were prepared by a facile solution casting method. The weight ratio of CNT-CN/GN-CN was varied from CNT-dominated to GN-dominated for the purpose of investigating their synergetic effects on the mechanical and thermal properties of PEN nanocomposites. Consequently, GN-CN/PEN composites demonstrated better mechanical and thermal properties than CNT-CN/PEN composites due to larger contact area between GN-CN and PEN matrix. Nevertheless, all CNT-CN/GN-CN/PEN composites exhibit enhanced mechanical properties than those of GN-only nanocomposites. With the increasing of CNT-CN/GN-CN weight ratio, the mechanical properties of CNT-CN/GN-CN/PEN composites increase, then decrease, and reach their maximums when CNT-CN/GN-CN weight ratio is around 4/4. From scanning electron microscope images, it is found that around that point GN-CN is flatly dispersed and CNT-CN is penetrated into GN-CN, capable of transferring stress load and thus decreasing interface loss. Thermal properties of CNT-CN/GN-CN/PEN composites once again confirmed the joint effect of CNT-CN and GN-CN, leading to improved thermal properties. In short, a synergistic effect between one-dimensional (1-D) CNT and two-dimensional (2-D) GN on the mechanical and thermal properties of nanocomposites have been demonstrated in these systems.

The Preparation and Properties of PEN/MWNT Nanocomposites

Polyarylene ether nitrile (PEN)/multiwalled carbon nanotube (MWNT) composites was prepared, and their rheological behavior and mechanical properties were studied. The PEN/MWNT composites have been fabricated via solution mixing by using ultrasound and dispersion agent, and then casting. This results show that the rheological and mechanical properties of the PEN/MWNT nanocomposites prepared by ultrasound treatment with sodium dodecyl sulfate increase more significantly than that of the ultrasound-treated PEN/MWNT composites and the untreated PEN/MWNT composites with the increase in the MWNT content. The rheological and mechanical properties of the PEN/MWNT composites were related with the content ratio of the MWNT and the preparation ways.Polyarylene ether nitrile (PEN)/multiwalled carbon nanotube (MWNT) composites was prepared, and their rheological behavior and mechanical properties were studied. The PEN/MWNT composites have been fabricated via solution mixing by using ultrasound and dispersion agent, and then casting. This results show that the rheological and mechanical properties of the PEN/MWNT nanocomposites prepared by ultrasound treatment with sodium dodecyl sulfate increase more significantly than that of the ultrasound-treated PEN/MWNT composites and the untreated PEN/MWNT composites with the increase in the MWNT content. The rheological and mechanical properties of the PEN/MWNT composites were related with the content ratio of the MWNT and the preparation ways.

High-performance PEN/GF crosslinkable thermoplastic composites: preparation, properties, and crosslinking reaction

The continuous glass fiber-reinforced polyarylene ether nitriles (PEN) composites were successfully fabricated from PEN pre-impregnated glass fabric mates and PEN films using a film-stacking method. The work involved heat treatment for crosslinking reaction of PEN, and so it provided an interesting comparison of how heat treatment can influence the properties of composites. Detailed study on heat treatments for crosslinking reaction of PEN in the catalysis of the ZnCl2 at high temperature promoting the thermal and mechanical properties of composites were also investigated. The results showed that the thermal and mechanical properties of composites were enhanced by heat treatment, which is due to the fact that PEN resins could be crosslinked by the catalytic action of ZnCl2 at high temperature and formed triazine rings with a more thermally stable structure.

Thermal degradation kinetics of poly(arylene ether nitrile) and its cross-linked polymer

The kinetics of the thermal degradation of poly(arylene ether nitrile) (PEN; cross-linked and uncross-linked) was investigated by thermogravimetric analysis. The corresponding kinetic parameters of PEN were determined using the Flynn–Wall–Ozawa and the Friedman method. The Satava method was also used to explore the probable degradation mechanisms of PEN. The results showed that the activation energy (E) obtained from the Flynn–Wall–Ozawa method was in good agreement with the value obtained from the Friedman method. The solid-state decomposition mechanisms of uncross-linked and cross-linked PEN were A2 (nucleation and growth) and R2 type (phase boundary–controlled reaction), respectively. The E and initial decomposition temperature of cross-linked PEN were higher than those of uncross-linked PEN, which indicates that cross-linking treatment is effective in enhancing the thermal stability of PEN.

In situ polymerization approach to poly(arylene ether nitrile)-functionalized multiwalled carbon nanotube composite films: thermal, mechanical, dielectric, and electrical properties

Abstract Poly(arylene ether nitrile) (PEN)-functionalized multiwalled carbon nanotube (MWNT) composites were successfully prepared via an in situ polymerization method based on the combination of nucleophilic aromatic substitution polymerization with simple acylate-functionalized MWNTs (MWNTs-COCl) in the presence of nitrile monomers. The structure and morphology of PEN-MWNT composites were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. The improvement in the thermal stability and mechanical properties of PEN-MWNT films was achieved because of the good-quality dispersion of MWNTs and strong interfacial interaction between the PEN matrix and MWNTs. The most important result is that the dielectric constant and electrical conductivity can be remarkably enhanced by a high MWNT content.