Synthesis of random or tapered solution styrene–butadiene copolymers in the presence of sodium dodecylbenzene sulfonate as a polar modifier

Random or tapered solution styrene–butadiene copolymer (SSBR) is very difficult to prepare in an isothermal batch process without the use of polar modifiers because of the diverse reactivity ratios of the styrene and the butadiene in hydrocarbon solvents. In the presence of polar modifiers, the random SSBR can be synthesized by anionic living polymerization with the variety of microstructures, which results in the change of glass transition temperature (T_g). This article will discuss the use of sodium dodecylbenzene sulfonate as a polar modifier in isothermal batch process that controls the microstructure of the SSBR resulting in a random as well as tapered SSBR with low T_g (?67°C to ?80°C). The T_g of SSBR was controlled by the styrene content rather than the microstructure of polybutadiene. Physical properties of SSBR compounding were discussed for tire tread applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Enhancement of fibroblastic proliferation from photoreactive starch with immobilized epidermal growth factor

Carboxymethyl starch was modified by the incorporation of an azidophenyl group to prepare photoreactive starch, and characterized by Fourier transform infrared reflectance (FT‐IR), proton nuclear magnetic resonance (¹H‐NMR), and ultraviolet (UV) spectroscopy. Photo‐irradiation immobilized the Az‐starch on a polystyrene plate and it was stably retained on the surface. The protein containing immobilized Az‐starch was also immobilized on a stripe micropatterned plate. UV irradiation time and Az‐starch concentration were used to alter the physical properties of Az‐starch and consequently control the rate of epidermal growth factor (EGF) release. The Az‐starch that released growth factor was not cytotoxic to 3T3‐L1 fibroblast cells, and the immobilized EGF maintained its activity and induced cellular proliferation in vitro. These results suggest that Az‐starch could be useful as a clinical synthetic material for medical applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Optimization of LC droplet size and electro‐optical properties of acrylate‐based polymer‐dispersed liquid crystal by controlling photocure rate

We investigated the effects of the different content ratios of 2‐ethylhexylacrylate (2‐EHA) and 2‐ethylhexylmethacrylate (2‐EHMA) on the relationships among the photopolymerization rate, morphology of liquid crystals (LCs) droplets, and electro‐optical properties of trifunctional urethane acrylate‐based polymer‐dispersed liquid crystal (PDLC) systems. Photo‐differential scanning calorimetry (DSC) analysis and resistivity measurement revealed that increasing 2‐EHMA content gradually decreased the photocure rate of trifunctional urethane acrylate‐based PDLCs, which prolonged the phase separation between the LC molecules and the prepolymers. Morphological observations and electro‐optical measurements demonstrated that trifunctional urethane acrylate‐based PDLCs with the 2‐EHA:2‐EHMA ratios from 4:1 to 3:2 in weight percent formed the favorable microstructures of LC droplets being within the range of 1–5 µm to scatter light efficiently and showed the satisfactory off‐state opacity and on‐state transmittance and the relatively low‐driving voltage. The microstructures of LC droplets and electro‐optical properties of trifunctional urethane acrylate‐based PDLCs could be usefully optimized by controlling the photocure rate using the different 2‐EHA/2‐EHMA content ratios. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3098–3104, 2013     

Encapsulation of aliphatic amines into nanoparticles for self-healing corrosion protection of steel sheets

A noble approach based on the encapsulation of corrosion inhibitors has been presented, which are capable of improving the active corrosion protection without negatively influencing the barrier properties of the coating layers. Polymeric nanocapsules loaded with six types of amine corrosion inhibitors were synthesized by multi-stage emulsion polymerization. Depending on the basicity and water solubility of amines, different amounts of releasable corrosion inhibitors were encapsulated into the polymer capsules. Encapsulated organic amines were generally well released under alkaline conditions, and linear amines were more easily released from inside capsules than branched ones. The nanocapsules were incorporated into the coating resin and were coated on cold-rolled steel sheets to investigate corrosion protection efficiencies. The corrosion inhibitive efficiencies of the nanocapsule-containing coating layers were evaluated by electrochemical impedance spectroscopy (EIS) and scanning vibrating electrode technique (SVET). In this study, it was revealed that the intrinsic properties of the amines as well as their encapsulation/release behaviors determined the barrier property and self-healing protection capability of the coating layer.     

Effect of Mn Dispersion on Gas Phase Ozone Decomposition at Room Temperature Using Natural Manganese Oxides

In this study, various analyses were performed to evaluate the ozone removal characteristics using natural manganese ore (NMO) at room temperature. NMO exists primarily in the form of MnO₂, and the specific forms of manganese oxide are formed as the calcination temperature increases. The activity tests, XRD, BET, and XPS analyses confirmed that the dispersion of manganese site exposed to the surface was a critical factor for ozone removal using NMO. To evaluate the actual application of NMO as a catalyst for ozone decomposition, NMO was also made as a form of monolith; as a result, the catalyst showed an excellent conversion rate (over 80%) even at space velocity 30,000 h^?1.     

贫瘦煤配煤炼焦试验及应用

对贫瘦煤进行工业分析、镜质组反射率分析和成焦分析,并对其进行20kg小焦炉的配煤炼焦试验和生产应用,研究分析表明,采用贫瘦煤配煤炼焦在合理调整配比的情况下能够生产出质量合格的焦炭。     

A study on sulfonated poly(arylene ether sulfone) membranes containing two different types of SiO2 for a high temperature and low-humidified polymer electrolyte fuel cell

Two different types of silica oxide were prepared as filler in sulfonated polymers for fuel cell applications operated under water deficient environment. SiO₂ nanoparticle and thiol-embedded SiO₂ nanoparticles were mechanically mixed with sulfonated (arylene ether sulfone) solutions, and then the mixtures were cast to prepare composite membranes. The composite membranes with different amount of SiO₂ were prepared to investigate the effect of two types of SiO₂ nanoparticles on ionic conductivity with relative humidity at 120 °C. In addition, ion exchange capacity, water uptake, thermogravitational analysis, differential scanning calorimetry were studied. As results, the composite membranes containing thiol-embedded SiO₂ showed better water-channel forming ability at low relative humidity less than 50% in this study. Under full hydration of the composite membranes, the composite membranes containing pure SiO₂ nano-particles have higher ionic conductivity since the thiol-embedded SiO₂ might cause steric hindrance to make water channel well connected. Thus, below 50% relative humidity, the composite membranes containing 10 wt% of thiol-embedded SiO₂ showed the best ionic conductivity. It is very promising for polymer electrolyte fuel cells operated normally under 50% relative humidity at cathode.     

电磁屏蔽材料的应用研究进展

简要阐述了电磁屏蔽材料的重要性以及电磁屏蔽机理,综述了近年来重要的电磁屏蔽材料,特别是电磁屏蔽涂料、电磁屏蔽织物和电磁屏蔽塑料的应用及研究进展。     

水煤浆气化炉使用煤质管理探讨

针对水煤浆气化装置使用煤质比较苛刻,煤质管理难度较大的问题.文章主要从技术角度和管理角度对煤质管理进行剖析,探讨了煤质管理措施及可行性.     

浅谈应用化学特色专业的建设

特色专业建设是高校在高等教育大众化新形势下得以生存和发展的重要战略手段。本文结合我校的实际,概述了应用化学专业特色建设目标、建设方向、专业定位及专业建设措施,在特色专业建设方面进行了有益的探索,有力地推动了"质量工程"建设,成效较为显著。