Advanced Materials Research Vols. 306-307

Abstract: The straight and orderly microrods of polypyrrole(PPy) was synthesized in a microemulsion system consisted of cetyltrimethylammonium bromide(CTAB), n-pentanol, water and pyrrole by chemical oxidative polymerization, in which CTAB was used as soft templates and APS was used as the oxidant. Fourier-transform infrared spectroscopy (FTIR) was used to characterize the structure of the PPy microrods. Transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) was used to characterize the morphology of the samples. We discussed the impact of temperature, the adding way of the oxidant, the amount of cosurfactant n-pentanol to the morphology of PPy microrods. The results showed that straight and orderly PPy microrods with a diameter about 300nm and a length up to 20μm were synthesized when the temperature was kept at room temperature (25°C), the dropping time of APS was more than 1.5h, the ratio of CTAB to n-pentanol was 0.6:1, and the polymerization time was about 24h. We studied the growth process of PPy microrods by HTEM analysis. HTEM images revealed that the growth process of PPy changed from hollow microrods, semi-hollow microrods, and finally solid microrods.

Abstract: Frictional characteristic of three kinds of polymeric material was studied by Mark II slipmeter under the condition of different couple materials and test conditions in order to understand the frictional mechanism of people’s walking deeply and decrease the probability of accidents caused by slips and falls. The results indicate that test conditions and couple materials influent friction characteristic of polymeric materials but the influence of test conditions is more significant. In the three test conditions, the friction coefficient of dry condition is highest and that of oil condition is lowest. The friction coefficient of polymeric materials on different floor samples had different trend indicated that there was interaction between shoe sole samples and floor samples.

Abstract: A new ion-imprinted polymer (IIP) material was synthesized by copolymerization of 4-vinylpyridine(VP) as monomer, ethylene glycol dimethacrylate(EGDMA) as crosslinking agent and 2,2΄-azobisisobutyronitrile(AIBN) as initiator in the presence of Pb–1,5-diphenylcarbazone(Pb-DHCB) complex. Blank non-imprinted polymer (NIP) were prepared under identical conditions without the use of lead imprint ion. The synthesized polymers were characterized by IR spectroscopy and elemental analyzer techniques. Of the several polymers synthesized, only the imprinted polymer formed with binary complex of Pb²⁺–DHCB showed quantitative enrichment of lead ion from aqueous solution. The relative standard deviation of the five replicate determinations of Pb (II) was3.26%. The detection limit for 150 mL of sample was 1.6 µg L-1 using flame atomic absorption spectrometry. The developed method was successfully applied to the determination of trace lead in environmental samples with satisfactory results.

Abstract: A modification was proposed to overcome problems of inaccuracy while traditional end group analysis was applied for hydroxyl value assay of polylactic acid oligomer owing to hydrolyzation. The modified method possessed simplification and accuracy resulting from avoiding hydrolyzation of polylactic acid oligomers, and it could be used for characterising molecular ingredient of polylactic acid oligomers, while the other techniques, such as 1H-NMR, Fourier transform infrared spectroscopy and viscosimetry, were applied at the same time.

Abstract: Conducting polymer – polypyrrole (PPy) microstructures were fabricated in an aqueous solution of dodecylbenzenesulfonic acid (DBSA) by electrochemical polymerization. The study implied the concentration of DBSA had great effect on the morphologies and conductivities of PPy microstructures. At lower DBSA concentration (0.2M), no obvious microstructures were generated. Increasing DBSA concentration, some novel “chayote-like”, “flower-like” microstructures were obtained by modulating electrochemical conditions. The growth process of microstructures was studied by scanning electron microscopy and relevant mechanism was discussed. Raman characterizations indicated that the microstructures were made of conductive PPy doped by DBSA.

Abstract: A cost-effective better performing silicone waterproofing agent interpenetrating polymer network coating for the protection of concrete has been developed. The working mechanism of the silicone polymer on the concrete was revealed and the effect of the material on the water absorption, chloride diffusion coefficient of concrete was analyzed. The results showed that the deep penetration of silicone material formed a hydrophobic layer and provides an effective protection against water corrosion and chloride ingress. A long-term protection can be guaranteed in case the surface of the concrete is waterproofing.

Abstract: Neodymium ion imprinted polymers (IIP) were synthesized by formation of ternary complexes of neodymium ion with Vanillin Benzidine(VLB) and 4-vinylpyridine (VP) as chelating agent following copolymerizing with styrene as func­tional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linking monomer using 2,2´-azobisisobutyronitrile as initiator. Control polymers（CPs） were prepared under identical conditions without the use of neodymium imprint ion. The synthesized polymers were characterized by IR spectroscopy and elemental analyzer techniques. Of the several polymers synthesized, only the imprinted polymer formed with ternary complex of Nd³⁺–VLB–VP(1:1:2 IIP) showed quantitative enrichment of neodymium ion from aqueous solution.

Abstract: A novel polyfluorene derivative, poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7- fluorene)-alt-2,7-(9,9- p-divinylbenzene)] (P-1) was synthesized by the palladium-catalyzed Suzuki coupling reaction and it’s quaternized ammonium polyelectrolyte derivatives was obtained through a postpolymerization treatment on the terminal amino groups. The electrochemical and optical properties of the resulting copolymers was fully investigated. The results showed that the new polyfluorene derivative had potential useful in used as materials for electronic conductivity, chemical and biological sensors that derive from its highly conductive and strong fluorescence.

Abstract: Ammonium polyphosphate (APP) is a widely used intumescent flame retardant ingredient, it has six crystalline forms, APP-V is seldom studied in literature. In this study, APP-V was prepared by process of diammonium phosphate (DAP)+P₂O₅ as raw material, and melamine as condensation agent under dry ammonia. Its properties such as water solubility was tested and compared with APP-II. Further characteristics techniques such as FTIR, XRD, and TGA were used to characterize this product.

Abstract: Polypyrrole (PPy) nanoparticles were successfully synthesized from the gelatin solution. PPy nanoparticles with different size and morphology are prepared by changing the preparation conditions including the gelatin concentrations, with surfactant or not. The characteristics of the obtained PPy particles was collected by scanning electron microscopy (SEM), The X-ray diffraction(XRD), Fourier transformation infrared(FT-IR) spectra and Four-probe conductivity meter. The results indicated PPy could form nanoparticles, whereas some bigger spheres occurred when the gelatin concentration is 0.05g/L and the conductivity of the PPy is 0.05S/cm. The possible mechanism was proposed that the gelatin is used as a morphology-directing agent in the polymerization process.