Zhou Lincheng

Photo-Heat Transition of Coatings Derived from Furfural Resin and Fe2 O3 Nanoparticles

A composite coating based on furfural matrix resin and Fe2O3 nanoparticles was prepared by the ultrasonic mixing of furfural with Fe2O3 nanoparticles. Coatings obtained from this mixture exhibited improved photo-heat transition properties. The composition, structure and properties of the composite coating were investigated using transmission electron microscopy (TEM), Fourier transform infrared (FTIR), thermogravimetric analysis (TGA) and spectrophotometry. The TEM results indicated that the size of resulting Fe2O3 particles were in the range of 50 to 100 nm. The initial decomposition temperature of the composite coating was 250°C. The solar absorptivity (αs) of the composite coatings was as high as 90%, and its emission rate (εn) was reduced to 56%, while the relative eff iciency of light-heat transition (αs/εnK) was about 1.6. The nanocomposite coatings exhibited excellent abrasion resistance, weatherability and water resistance due to the formation of a three-dimensional network structure during the thermal curing process. The results indicate that the nanocomposite material could be used as a solar light-heat transition coating that could be employed in solar hot-water collection.

Synthesis and Properties of PMR Matrix Resins of Poly(Pyrrolone-Benzimidazole)s

PMR type of poly(pyrrolone-benzimidazole) copolymers (PPBI) were synthesized by the polycondensation of monoethyl ester of cis-5-norbornene-endo-2,3-dicarboxylic acid (NE), diphenyl-isophthalate (DPIP), diethyl ester of 4,4′-oxydiphthalic acid (ODPE) and 3,3′-diaminobenzidine (DAB) or 3,3′,4,4′-tetraamindiphenyl ether(TAD) in a mixing solution of anhydrous ethyl alcohol and N -methylpyrrolidone (NMP) under different temperature and pressure procedures. The resulting resin solution showed an excellent solubility in polar organic solvents and good stability at room temperature, while the corresponding PPBI molded powder and molded plate could be prepared by undergoing amidation, imidization, cyclization and crosslinking reactions when the reaction temperature would be increased from 150 to 350°C, especially, the crosslinking structure formed by the reverse Dials-Alder reaction at 270-290°C under 2.5-3.5 MPa pressure displayed by the pressure meter. The chemical reactions and properties of the resulting PPBI molded powders and molded plates were studied by means of FT-IR, TGA, DMA methods, and the results indicate that the PPBI materials obtained hold excellent thermal stability and processability, the initial decomposition temperature > 600°C and its T g defined by the peak temperature in tan δ curve from the DMA method is 448°C (DAB) or 423°C (TAD) for PPBI-20 molded plate.