Dezhi Han

TG/FTIR analysis on co-pyrolysis behavior of PE, PVC and PS.

The pyrolysis and co-pyrolysis behaviors of polyethylene (PE), polystyrene (PS) and polyvinyl chloride (PVC) under N2 atmosphere were analyzed by Thermal gravimetric/Fourier transform infrared (TG/FTIR). The volatile products were analyzed to investigate the interaction of the plastic blends during the thermal decomposition process. The TGA results showed that the thermal stability increased followed by PVC, PS and PE. The pyrolysis process of PE was enhanced when mixed with PS. However, PS was postponed when mixed with PVC. As for PE and PVC, mutual block was happened when mixed together. The FTIR results showed that the free radical of the decomposition could combine into a stable compound. When PE mixed with PVC or PS, large amount of unsaturated hydrocarbon groups existed in products while the content of alkynes was decreased. The methyl (-CH3) and methylene (-CH2-) bonds were disappeared while PVC mixed with PE.

Preparation of Size Controllable MgO Nanoparticles via Reverse Microemulsion Method

Nanoparticles of MgO were successfully prepared in Triton X-100/n-hextnol/cyclohexane/water W/O microemulsion system. Basic preparation conditions were determined. TG-DTA showed that the proper calcination temperature was 450 oC. The nanoparticles were characterized by XRD and IR measurements in order to determine the crystal phase and component of the products. The morphological feature of the nanoparticles has been investigated by TEM. The result of XRD pattern demonstrated that the particles were exactly indexed to a cubic rock salt structure of MgO. There are no organic or inorganic impurities appeared after 450 oC calcination. The result of TEM showed that the MgO nanoparticles were spherical and uniform. The UV-visible spectra demonstrated the phenomenon of absorption blue shift, which is the evidence of quantum confinement effect, with the decrease of water/surfactant(R) value. Average size of the nanoparticles increased with increasing R value.