Advanced Materials Research Vols. 284-286

Abstract: To avoid the formation of layer-pore structure and flocculation caused by the excessive introduction of nonionic surfactant detergent polyoxyethylene 20 cetyl ether (Brij58) into poly N-isopropylacrylamide/inorganic nanoclay hectorite hydrogels network (PLH hydrogels), inorganic nanoclay hectorite content, severed as physical cross-linker, was increased from 1wt% to 3wt%. The morphology, temperature- responsibility, capacity of water absorption and swelling kinetics of resulting PHL hydrogels were investigated by SEM, DSC and Gravimetric method, respectively. It was found that PLH hydrogels would keep well honeycomb-like pore with increasing hectorite content. Furthermore, PLH hydrogels exhibited good temperature sensitivity regardless of physical cross-linker content.

Abstract: Flame retarded ethylene-vinyl acetate copolymer (EVA) was prepared in a melt process containing melamine phosphate (MP), or MP in combination with dipentaerythritol (DPER) as flame retardants. The influence of MP and MP/DPER on flame retardant properties of EVA was investigated by limiting oxygen index (LOI) and UL 94 test. Thermal decomposition of the flame retardants and flame retarded EVA composites was studied by the thermogravimetric analysis. The results show that MP used alone in EVA does not exerts good flame retardancy, even at a loading of 50wt%. It is found that the flame retardant properties of the EVA/MP/DPER composites is greatly improved when a suitable amount of MP substituted by DPER. Moreover, mechanical properties of the EVA composites were studied.

Abstract: TCNT(Triton® X-100 pre-treated carbon nanotubes)/ PP (Polypropylene) composite has been successfully prepared and charactered by SEM, electrical tests. It was found that the best usage of Triton X-100 (P-octyl polyethylene glycol phenyl ether) was 80 wt% based on the CNTs. The results showed that the TCNTs could effectively improve the composites’ electrical conductivity over pristine CNTs. The mechanisms for the results have been discussed.

Abstract: Polystyrene(PS)/Polystyrene-expanded graphite(EG)(PS/PSEG) composites were prepared by melt blending, using a variety of PSEG. The electrical and mechanical properties of the PS/PSEG were measured. Mechanical property measurements of composites indicated higher impact strength and lower tensile strength with increasing content of PSEG. Exfoliated graphite has seen a significant reduction for composites in electrical resistivity.

Abstract: Thiophene derivative polymer is an important kind of conductive polymers. They often have good electrochemical activity, environment stability and ease of processing. Here, 3-bromothiophene and 3-thiophenezoic acid as monomers, using chemical oxidation approach, the poly (3-thiophenezoic acid) (PTPA), the copolymer of 3-bromine thiophene (BTP) and 3-thiophenezoic acid (TPA) are synthesized in the media of chloroform or methanol. The structures of both polymers are characterized with FT IR, NMR and UV-vis. The results showed that the reactivity of TPA can be improved after alkalizing. The copolymer has strong absorption in the UV region. Its absorption band and intensity are higher than that of PTPA.

Abstract: The objective of this study was to find out a kind of MIP which was suitable for recognizing NG in aqueous medium. A non-covalent NG-β-CD imprinted polymer was prepared by using β-cyclodextrine (β-CD) as a functional monomer, naringin (NG) as a template molecule and hexamethylene diisocyanate (HMDI) as cross linker. The binding property and selectivity were evaluated by the equilibrium binding experiment, its imprinting factors α is 1.39.

Abstract: Thermoplastic vulcanizates (TPVs) of natural rubber (NR) and polypropylene (PP) (60:40) containing various dosages (0.5-5.5phr) of peroxide were prepared using a Haake Rheocord. The effects of peroxide content on the crosslink density, thermal behaviors, morphology, mechanical and rheological properties of NR/PP TPVs were studied. The crosslink density of TPVs increased with increasing of peroxide content. However, the tensile strength, tear strength and elongation at break obtained the maximum values when 2.5phr peroxide was added, which was ascribed to the presence of smallest particle size of crosslinked rubber phase at this peroxide content. It was proposed that the effect of DCP, which not only initiated crosslink reaction in NR phase, but also degraded the polypropylene molecules, played an important role in determined the morphology and properties of TPVs. The viscosity of TPVs decreased with shear stress, indicating pseudoplastic nature of the TPV samples. The elastic modulus of the samples gradually increases with the increase in DCP content.

Abstract: The carbazoled poly(arylene imino)s (c-PAI) have been synthesized via palladium-catalyzed polycondensation of 3,6-diamino-N-(2-ethylhexyl)carbazole with different aromatic dibromides. The structure of c-PAI were characterized by means of FT-IR, ¹H NMR spectroscopy and elemental analysis, the results show an agreement with the proposed structure. The thermal properties of c-PAI were detected by DSC and TG. The result show that the polymers possess high glass transition temperature (Tg＞250°C ), good thermal stability with high decomposition temperatures (T_D＞410°C), In addition to the thermal properties, the optical properties were studied, including Uv-vis absorption, photoluminescence and time of flight (TOF).

Abstract: Sulfoned aromatic acid and o-phenylenediamine as the monomers, sulfoned-benzimidazole was obtained by condensation reaction. Poly(aryl sulfone benzimidazole) sulfone (PSBIS) as novel heat-resistant polymer was obtained by the condensation polymerization via Palladium-catalyzed aryl amination reaction of sulfoned-benzimidazole and aromatic dibromide. Differential scanning calorimetry (DSC) and thermal analysis (TG) measurements showed that the polymer synthesized possessed high glass transition temperature (T_g>321°C), good thermal stability with high decomposition temperature (T_D>540°C) and good solubility.

Abstract: In order to study the performance of asphalt mixture with PR.S, Marshall test and rutting, low temperature bending, water stability test were done. The results indicated that the additive PR.S played an important role in improving high-temperature anti-rutting performance of asphalt mixture because of the cementation, reinforcement, inter-lock and adsorption function. With the amount of PR.S increasing, high-temperature performance of asphalt mixture increased gradually and low-temperature performance declined a little. In order to decide the appropriate amount of the additive PR.S, the low-temperature anti-cracking performance should be mainly considered when asphalt mixture was designed. The other performance of asphalt mixture with the amount of 0.45% PR.S could also meet the requirements of the specification. Considering its great contribution to anti-rutting, PR.S asphalt mixture was more properly adopted in the middle layer of asphalt pavement.