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.

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.

Copper powder is synthesized by hydrothermal treatment using the copper powder obtained from the chemical reduction method as a precursor. The copper powder is also treated in benzotriazole solution. The powder X-ray diffraction patterns and SEM photomicrographs exhibit that the copper powder possesses perfect crystallinity and narrow size distribution. The thermal behavior of the three kinds of copper powder is evaluated by thermogravimetry and derivative thermogravimetry. Comparing with the sample prepared by means of the chemical reduction method, the copper powder treated under hydrothermal condition displays a peak temperature of the formation of Cu2O shifting from 60.49

Sn-doped (Ba, Sr) TiO3 (BSTS) thin films have been deposited on highly (200) oriented LaNiO3 (LNO) thin films by sol-gel method. The atomic force microscope (AFM) images exhibited that the dopant Sn did not decrease the crystalline grain size of BST thin films. The structure of the BST film, determined by X-ray diffraction (XRD), presented the higher intensity (110) and (200) peaks, while the latter was distinctly induced by LNO layer. Evidently, Sn-doped BST thin films on LNO/Si substrate were found to decrease the dielectric constant and the dielectric loss, which is favourable to potentially improve the figures of merits (FD) of pyroelectric materials. The BSTS thin films on LNO layer also displayed an excellent leakage current property comparing with the BST thin film on Pt/Ti/SiO2/Si and LNO/Si substrates.