Polyarylene ether nitriles (PENs)/TiO2 nanocomposite has been successfully synthesized through the sol–gel process; the films were characterized by FTIR, XPS, SEM and TG. The dielectric properties of the films were also measured to find that the dielectric constant of nanocomposite films increases linearly with the TiO2 weight content and reaches 6.21 at a 20 wt.% TiO2 content. The nanocomposite films have favorable mechanical and thermal properties and are not sacrificing dielectric breakdown strength compared to that of pristine polymer. © 2004 Elsevier B.V. All rights reserved.

In this paper, a new kind of aliphatic biodegradable polyesteramide copolymers P (CL/AU) x/y based on e-caprolactone and 11-aminoundecanoic acid were synthesized by the melt polycondensation method. Hydrolytic degradation behavior of P (CL/AU) copolymers were studied by using FTIR, 1H-NMR and DSC. Chemical compositions, macromolecular weight, thickness of the test sample, and pH of the degradation medium have great effect on degradation rate. The degradation rate decreased with increase in aminoundecanoic acid content, macromolecular weight, and thickness of the test samples, but increased with incubation temperature and pH of the degradation medium. The degradation mechanism was studied according to the mathematical model developed by professor G. opferich.

A new kind of aliphatic polyetheresteramide copolymers (PEEAs) based on E-caprolactone, 11-aminoundecanoic acid, and poly (ethylene glycol) (PEG) were synthesized by melt polycondensation. The thermal and hydrolytic degradation behaviour of these copolymers was studied using FTIR, 1H-NMR, and TGA. PEG content, thickness of the test sample, and pH of degradation medium have great effect on degradation rate. The degradation rate increased with PEG content and pH, but decreased with thickness of the test sample.

Multi-walled carbon nanotube (MWNT) composites were fabricated using the screw extrusion and injection technique. The polymer-wrapped MWNTs were dispersed in fumed silicon dioxide with the help of ultrasonic stirring, and then further dispersed in a high density polyethylene (HDPE) matrix by a twin-screw extruder. It was found that there was a critical MWNT concentration around 1.0 wt% where a fine network of MWNT/SiO2 was formed. This gives the MWNT/HDPE composites much improved mechanical properties. From the mechanical property, it was found that the surface treatment of MWNT/SiO2 had a large effect on the performance of the composites. Thermogravimetric analysis (TGA) measurement showed that MWNT could stabilize HDPE when its weight content was greater than 2.0 wt%, whereas silicon dioxide accelerated thermo-oxidation of the composites.

The stabilization of polyesteramide (PEA) was studied by TGA, melt index and intrinsic viscosity. Primary antioxidant A1010 (0.6 wt.%) combined with 0.2 wt.% of hydroperoxide decomposer A168 is effective in stabilizing PEA; but the holding life of PEA in the extruder barrel is only 30 min, and the antioxidants are completely consumed when it is extruded four times. Fillers including heavy calcium carbonate (HCC), tricalcium phosphate (TCP) and talc affect both the thermal stability and mechanical properties of the resultant composites, which are discussed in detail. The Turcsanyi model can best describe the composition dependence of tensile strength of the HCC and talc filled PEA, and the Sato-Furukawa can best predict the Young’s modulus of HCC filled PEA, but is poor for the talc-filled material © 2003 Elsevier Ltd. All rights reserved.