Advanced Materials Research Vols. 781-784

Abstract: Monomers based on 2,1,3-benzothiadiazole bearing solubilizing side chains have been synthesized in high yields over four steps from readily available starting materials. A multistep synthesis of the electron-poor 5,6-bis (heptyloxy) benzo [[1,2,thiadiazole are presented. The new deficient acceptor has good solubility in organic solvents to permit an appropriate coating process.

Abstract: Phosphotungstic acid supported over silica catalysts were prepared, characterized and tested. The results show that silica-supported phosphotungstic acid with 50 wt% of loading amount indicates excellent catalytic performance for the polymerization of α-pinene. It is also found that the products are easily separated from reaction mixture and the silica-supported phosphotungstic acid catalysts are low-corrosive. Hence, a clean and environmentally friendly heterogeneous catalyst for α-pinene polymerization is reported.

Abstract: The dissolution process of benzene, toluene and ethylbenzene in amorphous polyethylene (PE) membrane was studied in this paper, and the solubility coefficients of the above organic molecules were analyzed and calculated by molecular dynamics simulation. The results showed: the solubility coefficient decreased with increasing molecular weights of organic molecules in the same temperature, and it also decreased with increasing temperature for the same organic molecule. Distribution of density field and energy field for organic molecules in PE were obtained. From the density distribution, the concentrated adsorbed area of the three kinds of molecules is clearly seen, which located at the more loose place in polyethylene membrane. From the energy distribution, it showed thehot spots of the organic molecules, which were the location that the organic molecules were most easily absorbed. The adsorption capacities of benzene, toluene and ethyl benzene in polyethylene membrane decreased in turn.

Abstract: The research relates to a method for preparing an in-situ crosslinked polymer coating. It has excellent solubility in aqueous alkaline solution, but didnt dissolve in general organic solvents and water. The crosslinked polymer coating was made through the reaction of a copolymer derived from diacetone acrylamide (DAAM) and ethacryloyloxyethyl-carbazochrome-p-toluenesulfonamide (MCTS) with a crosslinking agent, isonicotinyl hydrazide. The two components were dissolved in 3-methoxypropanol to prepare the coating solution, which was then coated to a grained and anodized aluminum substrate and dried at 120 °C for 5 min to obtain the crosslinked coating. There exists intermolecular hydrogen bond between the pyridine ring of isonicotinyl hydrazide and the sulfonamide group of the MCTS unit of the copolymer. The reaction between the hydrazide group and the carbonyl group during the drying process generated the hydrazone bond, resulting in the crosslinked polymer coating. The intermolecular hydrogen bond and the covalent bond render the coating insoluble in most organic solvents. However, the hydrogen bond was readily broken down when the coating was exposed to aqueous alkaline solution due to the ionization of the sulfonamide group, causing rapid dissolution of the coating. The coating was also used as the under-layer for the preparation of a double-layed CTP plate. The performance of the double-layed CTP plate was preliminarily studied.

Abstract: A thermosetting epoxy shape memory polymer was obtained by adding modifier end thioglycolic acid butyl glycol ester which prepared in our lab into E-44/D-230. The results show that the tensile and impact strength of modified epoxy are improved, and it can be bended as U style in thermal transition temperature, shape fixed rate is 100% after removing external force. When temperature is raised to thermal transition temperature again, the shape of modified epoxy can be restored completely. The time of recovery is between 178~183s and not effected by cycle times.

Abstract: This research aims to determine the influences of radiation-induced crosslinking on the mechanical properties of polymer blends between poly (lactic acid) (PLA) and thermoplastic starch (TPS). PLA and TPS were mixed at different ratios (90:10, 80:20, 70:30, 60:40) in the presence of a crosslinking agent using a twin screw extruder. The blends were compression molded into films. The film samples were irradiated by gamma radiation at different doses. Gel fraction was used to determine crosslinking efficiency. Results showed that gamma radiation was able to induce crosslinking for PLA/TPS blends. The gel fraction and mechanical properties decreased with increasing TPS content. The optimum ratio of PLA:TPS with the maximum gel fraction and mechanical properties was 90:10 and the optimum dose was 40 kGy by gamma radiation.

Abstract: The research of conductive polymer material has received the widespread attention and development. This article has introduced the classification and preparation methods of conductive polymer materials, conductive mechanism, application and research progress in various fields.

Abstract: Natural rubber compound using different silicas, including unmodified silica, admicellar-modified silica and silica with silane coupling agent, were studied. The properties including cure characteristics, mechanical properties and dynamic properties were examined with the comparison of three compounds. The results show that cure characteristics of admicellar silica/rubber compound (Ad-Si/R) was shorter than those of unmodified silica/rubber compound (Un-Si/R) and silane coupling silica/rubber compound (Sil-Si/R). Mechanical properties of Ad-Si/R and Sil-Si/R were better than those of Un-Si/R. In addition, wet grip and rolling resistance analyzed from tan δ (5 Hz) at 0°C and 60°C, respectively, by DMA were found that the wet grip of Ad-Si/R was the best, whereas the rolling resistance of Sil-Si/R was the best, in the comparison.

Abstract: Directly starting from D,L-lactic acid (LA) and melamine (MA), poly (lactic acid-co- melamine) [P(LA-co-MA)] as a kind of potential polymeric flame retardant is synthesized via melt polycondensation. The properties of P(LA-co-MA) s at different molar feed ratios are characterized by XRD, DSC and TGA. Most decomposition temperatures of P(LA-co-MA) s are higher than these of homopolymer poly (D,L-lactic acid) (PDLLA). For the char yield, all copolymers have higher char yield than PDLLA. Furthermore, the more MA in the feed content, the higher char yield.

Abstract: Distinguishing carton black and impurity is important for evaluating carton black’s dispersion in rubber. There are two types of impurities, filamentous impurity and scratch. According to the characteristics of filamentous impurity, the ratio of perimeter to solidity of region and hole’s area were calculated to distinguish this type of impurity. If hole’s area was larger than 3 or the value of the ratio larger than 160, the region was regarded as filamentous impurity. Scratch was very like line, which could be identified by the way of hough translation. The treatment of impurities based on morphology is helpful for improving the accuracy of detecting carton black and calculating carton black’s dispersion.