Advanced Materials Research Vols. 602-604

Abstract: The effects of initiator, modifier, electrolyte, and emulsifier on emulsion polymerization of styrene butadiene rubber were investigated. The results showed that the conversion could reach up to 70% within 12 hour with the same properties as conversion 62% without changing the kinds and specification by using the adjusted recipe: the amount of initiator was 10%, the mass ratio of initial amount to addition amount of molecular weight regulator was 100/20, addition time was at polymerization beginning 2 hour, the initial amount of electrolyte was 110%-115%, the total amount of emulsifier was 110%, the addition amount of emulsifier was 10% and adding time was at polymerization beginning 2 hour. the raw and vulcanizate properties of rubber crumb high monomer conversion of 70% by adjusting recipe were satisfied to meet the requirements of the superior product standard of styrene butadiene rubber.

Abstract: Hydroxyl functional hyperbranched polyester initiators initiated the ring-opening polymerization(ROP) of ε-caprolactone (CL) and the star-shaped polymer with PCL arms using hyperbranched polyester as nuclear was produced. Then, the bromide of star-shaped polymer, initiated the atom transfer radical polymerization (ATRP) of oligo(ethylene oxide) methacrylate (OEOMA) and the star-shaped polymer containing the arms of PCL-b-POEOMA was synthesized ,and the characterization of polymer structure was investigated by NMR.

Abstract: In order to enhance oil recovery and avoid the profile control agents degradation in the alkali/surfactant/polymer composite solution in the oil layer, the copolymer of AM (basic monomer), 2-EHA (salt resistance monomer with large lateral group) and VTEOS(temperature tolerance monomer) was prepared by free radical copolymerization method as the profile control agent. FT-IR and 1H-NMR were used for the structure characterization. Thermo gravimetric analysis, Core/Sand pack experiments and water drive displacement tests of copolymer particles were used to evaluate the properties. The results shows that the copolymer particles have good thermal stability, alkaline resistance, anti-salt property and excellent blocking property as profile control agent.

Abstract: Poly(bis(2-(trimethylamino)ethyl) 2-hydroxyl propylidene ammonium) chloride (PTMAEPAC) is one kind of oligomeric cationic polymer with a quarter nitrogen atom on its main and side chain. It was synthesized from Bis(2-trimethyl ammonium)ethyl ammonium chloride (TMAEAC) and epichlorohydrin (ECH) by copolymerization reaction, effects of reaction temperature, mole ratio of raw materials, reaction time, amount of solvent on the cationicity of product were studied. The structure of PTMAEPAC was confirmed by IR and 1H-NMR, and its anti-clay-expanding ability was studied. The results show that the cationicity of PTMAEPAC can reach 83.9% with the reaction time of 6h at 65°C when TMAEAC-to-ECH mole ratio is 1.2:1 and the amount of solvent is 30% in total. According to the IR and NMR analysis the product has the same structure with the aim compound. When the content of the product is 3 wt% it has a good anti-clay-expanding ratio of 96.1%.

Abstract: In this study, urea-formaldehyde resin was modified and used to bond three-ply plywood. The effect of hot press parameters on properties of plywood bonded by the modified urea-formaldehyde resin adhesive was investigated by an L(43) experimental design. The optimum technical parameters of hot press were obtained. Conclusions were as follows: (1) After modification, the free formaldehyde content of the urea-formaldehyde resin and the formaldehyde emission of resulting plywood were reduced by 74% and 70%, respectively; (2) The optimum technical parameters were 140°C of hot-pressing temperature, 80s/mm of hot-pressing time, 300g/m2 of glue content, and 0.8% of curing agent; (3) Under the optimum technical parameters, the bond strength and the formaldehyde emission of the plywood was 1.17MPa and 0.47mg/L, respectively.

Abstract: Epoxy resin is widely used in many electronic packages, the ability to predict properties of cross linked epoxy resin before experiments will facilitate the process of materials design. Molecular dynamics (MD) is a powerful method that can simulate the materials at atomic scale and it can be used to predict the performance and properties of a wide range of materials. In this work, the properties of the cross-linked epoxy resin compound at high temperature were studies by MD simulations. The relations of the glass transition temperature (Tg) and properties of the cross-linked epoxy resin were investigated. The results show that Tg can be estimated by the plot of non-bond energy at different temperatures, and consist with the experimental data.

Abstract: Silicon dioxide plays an important role in integrated circuits and microelectronics. However, the experiments have limitations in micro/nano-scale characterization of fracture properties at high temperatures. In this paper, the structural and fracture properties of amorphous silicon dioxide (a-SiO2) were studied at temperatures up to 1500K. The simulation results consist with the experiments on pair distribution functions, structure factor and angular distributions.

Abstract: This work aims at developing an accurate measurement of characterization flow field of polymer melts by small-angle light scattering (SALS). In this article we propose a new method, based on radial basis function neural network (RBFNN) for predicting the optimum vibration field parameters. A laser light passes through polymer melts in the visual slit die. The results reported in this study were obtained with polystyrene (PS) with rotation speed at 20 rpm. In order to capture the scattered light, a polarizer and an analyzer are placed before and after the polymer melts. RBFNN inputs consist of frequency and amplitude, which are used as input parameters to predict the maximum light intensity projection area. RBFNN predicts that the optimum value of frequency, amplitude are 15.86 Hz and 0.20mm, respectively. And the maximum light intensity projection area is predicted to be 9260 pixels.

Abstract: The flame retardancy of a thermally stable flame retardant, poly(bisphenol phenyl dichlovophosphate) (PBCL) and its synergistic effect with ammonium polyphosphate were studied in ABS. TG result indicated the good thermal stability and char-forming ability of PBCL. Thermal stability and flammability properties of ABS/APP/PBCL composites were investigated by thermogravimetric analysis (TGA), oxygen index test (LOI) and micro calorimeter calculate test (MCC). The results showed that the synergistic effect of APP and PBCL improved the thermal stability and flame retardancy of ABS, which was favorable to yield more stable layer at higher temperature and enhanced the char residue of ABS resin.

Abstract: The melting, crystallization behavior, morphology and mechanical properties of poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT)/calcium carbonate (CaCO3) composites were investigated by means of differential scanning calorimetry (DSC), scanning electron microscopy(SEM), and mechanical test. It is shown that PBAT decreases the crystallinity, while CaCO3 increases the crystallinity of the composites. A synergistic toughening effect is obtained by the combination of CaCO3 and PBAT. The optimum mechanical properties can be achieved in case of the composite (PLA: PBAT: CaCO3=60: 20: 20).