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.

Biodegradable polyesteramide copolymer P (CL/AU) based on €-caprolactone and 11-aminoundecanoic acid was synthesized by the melt polycondensation method. Polyesteramide (PEA) microspheres were prepared by a simple O/W emulsion solvent evaporation method. The effects of variations in preparation parameters (such as emulsifier concentration, polymer concentration, polymer solution adding rate, stirring rate, and whether vacuum was applied) were studied in detail. The obtained microsphere morphologies were observed using an optical microscope and via scanning electron microscopy (SEM). The particle size distribution was determined using a Malvern laser particle sizer. When the PEA microspheres were incubated in PBS saline, the particle size increased at first, and then decreased after a longer time period; the theory that this behavior was due to degradation of the microspheres was confirmed by SEM.

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.

Glass fiber (GF) reinforced phenolphthalein-based polyarylene ether nitrile composites were prepared through melt blending, and the composites were characterized by various methods to find that both the mechanical and thermal properties of the silane coupling agent treated GF reinforced composites were improved with the increase of GF content. Tensile strength, flexural strength and Izod impact strength got their highest values with GF content at 35 wt.%, 30 wt.% and 25 wt.% respectively. The heat distortion temperature (HDT) of 30 wt.% GF reinforced composite is 284

Poly (D, L-lactide) (PDLLA) degraded at processing temperature under air and nitrogen. A random chain scission model was established and used to determine the activation energy Ea, and FT-IR, 1H and 13C NMR were used to elucidate the degradation behavior under different atmospheres. Results showed that there were two to three stages. The 1st stage was dominated by the oligomers containing carboxylic acid groups and hydroxyl groups, during which oxygen and nitrogen had little effect on the degradation, thus they share similar Ea. When the oligomers were consumed over or evaporated, the 2nd stage began, and oxygen had a promoting effect on the thermo-oxidation process, resulting in the great decrease in Ea. The third stage of PDLLA was observed when it degraded under nitrogen over 200