Preparation and characterization of a novel environmentally friendly coal dust suppressant

To mitigate the dust dispersion pollution in the open-pit coal mines, this study experimentally develops a novel environmentally friendly coal dust suppressant. The experiment uses naturally biodegradable soybean protein isolate (SPI) as the main material and utilizes anion surfactant sodium dodecyl sulfate (SDS) to modify SPI. In the carboxymethylcellulose sodium and sodium silicate and other auxiliary agents, this process produces gives rise to the SDS-SPI coal dust suppressant. Experimental characterization of the developed dust suppressant reveals that the viscosity of the 5% dust suppressant solution can reach 24.6 mPa s. Correspondingly, the compressive strength reaches 0.48 MPa, and the dust suppression efficiency can reach 93.47% with the presence of force 9 wind. Furthermore, this study uses Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) to analyze the dust suppression mechanism of the developed dust suppressant. It is observed that a layer of compact hardened shell is formed at the surface of the coal powder treated with the newly developed dust suppressant. Also, there exists a strong cementing effect among dust particles, yielding a decent cementing performance. Therefore, the present dust suppressant can effectively suppress dust dispersion in the open-pit coal mines, allowing a mitigation of the environmental pollution. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47354.     

基于木钠盐与NNO复配水煤浆添加剂制备试验研究

为克服单一添加剂的缺点,提高水煤浆性能,研制了一种基于木质素磺酸钠与亚甲基二萘磺酸钠(NNO)复配的新型水煤浆添加剂,研究了添加剂复配比、添加剂用量、煤粒级配及温度等对水煤浆成浆性能的影响。结果表明,木质素磺酸钠与亚甲基二萘磺酸钠的复配比为1∶2,添加剂用量为0.8%,0.25、0.18、0.12 mm煤粒质量比为1∶2∶3.5时制备的水煤浆具有较好的稳定性及流动性,黏度为2 000 m Pa·s,浆液流动性达B级,且放置1、3 d后,落棒实验均显示一棒落底。水煤浆黏度与温度的自然对数成线性关系,即随着温度的升高,水煤浆黏度下降明显。     

Preparation and performance of a composite gel as a dust suppressant for coal transportation and storage

In the process of coal transportation and storage, a large amount of dust is inevitably generated, which seriously threatens the health of coal miners and causes the waste of resources. How to prevent and control the dust generated during coal transportation and storage is a key issue of coal mine occupational safety research. In this study, sodium alginate is reacted with 2-acrylamide-2-methylpropanesulfonic acid, and the resulting intermediate is graft copolymerized with acrylic acid to prepare an environment friendly dust suppressant product suitable for coal transportation and storage. The microscopic reaction and structure of the product are analyzed by infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The optimal synthesis conditions have been obtained by taking the strength of the coking coal as the single factor experiment evaluation index. Through the research on the related properties of the dust suppressant, it is found that this dust suppressant has excellent performance and an obvious dust suppression effect. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47819.     

铁路煤炭运输扬尘覆盖剂自动喷洒系统设计

中国铁路煤炭运输以敞车车型为主,在运输过程中对铁路沿线生态环境造成严重扬尘污染。为了解决铁路煤炭运输过程中的扬尘污染问题,研发了新型环保扬尘覆盖剂及自动喷洒系统装置。自动喷洒系统可实现扬尘覆盖剂溶液自动配置;溶液浓度、黏度、电导率、温度等数据在线监测;喷洒量根据车速自动调节;在车辆运行过程中实现喷洒作业,不需停车等特点。自动喷洒系统适应各种C车型,具有操作简便、运行稳定可靠、喷洒均匀,自动识别牵引机车和混编列车等优点,不影响机车车辆的安全和正常运行。自动喷洒系统人工使用量少,自动化程度高,抑尘作业成本比传统喷水降尘,遮盖篷布等方法低,实现了新型抑尘技术在铁路煤炭运输抑尘领域的工业化推广应用。     

一种环保型化学清洗剂的研制及性能研究

以柠檬酸、氨基磺酸、聚天冬氨酸钠、硫脲和助剂制备了一种固体环保型化学清洗剂.采用静态挂片和振动摇床试验法对清洗剂的腐蚀和生物降解性能进行了测定.采用极化曲线法和腐蚀试片扫描电子显微镜照相分别对缓蚀机理进行了研究.结果表明,该清洗剂对碳钢、不锈钢、铜和铝具有优良的缓蚀性能,28天后降解率可达94%以上.     

The effects of coal dust concentrations and particle sizes on the minimum auto‐ignition temperature of a coal dust cloud

Flash fires and explosions in areas containing an enriched combustible dust atmosphere are a major safety concern in industrial processing. An experimental study was conducted to analyse the effects of atmospheric coal dust particle sizes and concentrations on the minimum auto‐ignition temperature (MAIT) of a dust cloud. Two different coal samples from Australian coal mines were used. The coal dust particles were prepared and sized in 3 ranges, of below 74 μm, 74 to 125 μm and 125 to 212 μm, by using a series of sieves and a sieve shaker. A humidifier was used to increase the moisture content of the particles to the required level. All the experiments were conducted in accordance with the ASTM E1491‐06 method in a calibrated Goldbert‐Greenwald furnace. The results from this study indicate that coal dust properties, such as the chemical nature (H/C), concentration, particle size (D₅₀), and moisture content, impact on the MAIT. For coal dust concentrations less than 1000 g.m^?3, the MAIT decreases with increasing coal dust concentrations. On the other hand, for low concentrations of 100 to 15 g.m^?3, the MAIT becomes more reliable for particle size D₅₀ rather than for volatile matters.     

Preparation,characterization, structure,and dynamics of carboxymethyl chitosan grafted with acrylic acid sodium salt

Graft copolymerization of different vinyl monomers onto chitosan (Cs) and its derivatives can alter their properties and consequently expands their potential applications. In this study, carboxymethyl chitosan (CMCs) was prepared and characterized. Graft copolymerization of acrylic acid sodium salt (AAs) onto CMCs was accomplished by using ammonium persulphate (APS)‐induced free radical polymerization in aqueous medium under nitrogen atmosphere. Occurrence of grafting was confirmed and the effects of [AAs], [APS], reaction time, and temperature on the extent of grafting were studied. The influence of grafting yield on the structure and dynamics was also investigated by using differential scanning calorimetry (DSC), two‐dimensional wide‐angle X‐ray scattering (2D‐WAXS), scanning electron microscopy (SEM), and dielectric spectroscopy. Preliminary study, using dielectric spectroscopy, was carried out to the CMCs‐g‐AAs copolymer with grafting percent ～ 2900%, as an example, in a wide range of temperature (from 299 to 473 K) and frequency (from 1 × 10^?2 to 1 × 10⁵ Hz). One relaxation process with Arrhenius type was detected. This process has the characteristics of a secondary relaxation process related to local chain dynamics with activation energy of 53 ± 3 kJ/mol. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and characterization of acrylic acid‐treated bacterial cellulose cation‐exchange membrane

The feasibility of using bacterial cellulose as a source for environmentally compatible ion‐exchange membranes (IEM) was studied. Bacterial cellulose was modified with cation‐exchangeable acrylic acid (AAc) by UV‐graft polymerization to prepare membranes having ion‐exchange capacity (IEC) and greater structural density. Fourier transform infrared (FTIR) spectra showed that acrylic acids were successfully bound to bacterial cellulose. Morphological changes of acrylic acid‐treated bacterial cellulose were examined through scanning electron microscopy. A dense structure of the membrane increased with increasing UV‐irradiation time. Acrylic‐modified bacterial cellulose membrane showed reasonable mechanical properties, such as tensile strength of 12 MPa and elongation of 6.0%. Also the prepared membranes were comparable to the commercial membrane CMX in terms of the electrochemical properties, ie IEC of 2.5 meq g^?1‐dry mem, membrane electric resistance of 3 ohm cm², and transport number of 0.89. Copyright © 2003 Society of Chemical Industry     

煤炭运输用天然植物胶抑尘剂制备与应用

以天然植物胶为主要原料,复配少量合成水溶性高分子以及其他助剂,制备出一种煤炭运输抑尘剂。该抑尘剂符合铁道部行业标准TB／T3210．1-2009《铁路煤炭运输抑尘技术条件》第1部分抑尘剂的要求,使用时将其喷洒在煤炭的表面,可形成具有一定韧性和压缩强度的固化层,能够承受长时间车辆的颠簸和风力作用,对车体金属、漆层和橡胶无腐蚀作用。经过内蒙古一年的实际应用,使用该抑尘剂能够避免列车运输途中煤炭扬尘污染．同时也节约了煤炭资源．     

煤炭运输专用扬尘覆盖剂均匀腐蚀性能研究

为了解决煤炭运输过程中的扬尘污染和煤炭损耗问题,研制了抑尘效果显著的新型煤炭运输专用扬尘覆盖剂。为了保证扬尘覆盖剂在应用过程中不对运煤列车、汽车等交通工具的重要部件产生不良影响,以扬尘覆盖剂溶液为试验介质对交通工具重要部件的组成材料进行均匀腐蚀试验。通过对普通碳钢、TCS不锈钢、铝合金、醇酸油漆、火车用橡胶管的均匀腐蚀试验验证了煤炭运输专用扬尘覆盖剂具有无腐蚀的优良性能。煤炭运输专用扬尘覆盖剂可以广泛应用于各种交通工具。     

Polypropylene/polypropylene‐grafted acrylic acid blends for multilayer films: Preparation and characterization

Polypropylene (PP) was functionalized with acrylic acid (AA) and styrene (st) as a comonomer by means of a radical‐initiated melt‐grafting reaction. FTIR, ESCA, and ¹H‐NMR spectroscopies were used to characterize the formation of polypropylene grafted with acrylic acid (PP‐g‐AA) and polypropylene grafted with acrylic acid and styrene (PP‐g‐AAst). The content of AA grafted onto PP was determined by using volumetric titration. Blends of PP with 0–100 wt % of PP‐g‐AA were prepared by melt mixing. The effect of the modified polymer content on the surfaces of cast films was characterized through FTIR–ATR and ESCA analysis as well as contact‐angle, wetting‐tension, and ink‐adhesion measurements. The influence of the content of AA on the melting and crystallization temperature of PP was investigated by DSC. The contact angles of water on cast‐film surfaces of PP/PP‐g‐AA blends decreases with increasing modified polymer content and decreasing PP‐g‐AA molecular weight. A notorious improvement on wetting tension was observed with increasing modified polymer content and decreasing PP‐g‐AA molecular weight. From FTIR–ATR and ESCA spectra of the blends, a calculation was made of the carbonyl index on the films' surfaces. It was found that the higher the carbonyl index, the lower the contact‐angle value for the polypropylene blends. An increase in crystallization temperature of PP was observed when AA monomers were grafted into PP and with increasing PP‐g‐AA content in the blend, probably caused by a nucleation effect of AA monomers that would improve the crystallization capability of PP. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1497–1505, 2001     

Factors influencing absorbent properties of saponified starch‐g‐(acrylic acid‐co‐acrylamide)

Mixtures of acrylamide (AM) and acrylic acid (AA) were grafted onto gelatinized maize starch by using ceric ammonium nitrate (CAN) as an initiator. These graft copolymers were hydrolyzed with alkali to yield hydrogels. The effects of different reaction variables, such as the concentration of the initiator and crosslinker, initial dilution of monomers, gelatinization conditions of starch, and the ratio of AM and AA in the monomer feed, on the water absorption capacities of these hydrogels have been examined. Absorption increases on gelatinizing starch at a higher temperature for a longer time as smaller granules gelatinize only under these conditions. The higher proportion of AA in the monomer feed enhances absorption due to formation of polyelectrolyte. The optimum conditions for obtaining maximum water absorbency established in the present study are granular maize starch = 2.0 g; gelatinization temperature = 95°C; gelatinization time = 60 min; AM = 1.0 g; AA = 4.0 g; CAN = 0.008 mol/L; N,N′‐methylene bisacrylamide = 1%. The product so formed was saponified with NaOH and then precipitated in excess of methanol. The dried and finely powdered product showed the maximum water absorbency of 510 g/g. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2480–2485, 2000     

Water‐soluble copolymers. III. Two‐step terpolymerization of acrylamide,acrylic acid,and acryloyloxyethyl trimethylammonium chloride

Terpolymerization of acrylamide (AM), acrylic acid (AA), and acryloyloxyethyl trimethylammonium chloride (DAC) was studied in aqueous solution by a two‐step polymerization method, consisting of adiabatic polymerization until reaching a maximum temperature and following retaining temperature for maturation. A redox agent:promotor triad‐initiating system was employed as an initiator. The effects of various parameters on terpolymerization were investigated. The optimum values were obtained at the DAC:AA molar feed ratio and the total monomer concentration, at the oxidant:reductant ratio and total redox agent concentration, and at the promotor concentration and redox agent:promoter ratio. The structure of the terpolymer was identified by Fourier transform infrared (FTIR) and ¹³C NMR spectroscopy. And the terpolymer composition was agreed favorably with feed ratio. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3278–3284, 2007     

农用低成本超强吸水剂的制备工艺

概述了合成类吸水树脂在农用上的进展,提出采用低成本且工艺成熟的水溶液法,以丙烯酸(AA)、丙烯酰胺(AM)为基体、接枝可溶性淀粉进行三元单体共聚,经钠基膨润土改性,复合引发剂、复合交联剂制备低成本、易降解的合成类吸水性树脂。经实验改进和工艺条件优化后,树脂吸去离子水倍率可达1 940.9 g/g,吸自来水899.8g/g。采用红外光谱仪、热重分析仪、扫描电镜、X射线衍射仪等分析手段对合成树脂进行了分析表征,证实了产物为淀粉、丙烯酸及丙烯酰胺的共聚物。     

Preparation and properties of poly(siloxane‐ether‐urethane)‐acrylic hybrid emulsions

Poly(siloxane‐ether‐urethane)‐acrylic (PU‐AC) hybrid emulsions were prepared by introducing different hydroxyethoxypropyl‐terminated polydimethylsiloxane (PDMS) content into the acrylic‐terminated poly(ether‐urethane) backbone and then in situ copolymerizing with methyl methacrylate and butyl acrylate via emulsion process. The effects of PDMS on the particle size and viscoelastic behavior of the hybrid emulsions were investigated. Meanwhile, the hydrogen bonding, mechanical and thermal mechanical properties, water resistance, the surface gloss, and wettability of the resultant hybrid films were also studied. The results showed that all the hybrid emulsions showed shear‐thinning behaviors, and the introduction of PDMS resulted in the formation of the hybrid emulsions with increased average particle size and decreased viscosity. The chemical bonds built between PU and AC yielded higher than 73% crosslinking fraction in all the hybrid materials, but this value decreased with increasing PDMS content because PDMS reduced the hydrogen bonding interactions and enhanced the phase separation. As a result, an increase in the PDMS content led to an increase in the elongation, water resistance, surface roughness, and water hydrophobic of the films, but the tensile strength, hardness, storage modulus, and glass transitions temperature decreased. It is suggested that introduction of PDMS can provide the hybrid materials with the improved flexibility, water resistance, and surface hydrophobicity, which has potential application value in the fouling‐release coatings, biomaterials, and surface fishing. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44927.     

表面活性剂和硅烷偶联剂有机复合改性蒙脱土的制备及性能表征

为增加蒙脱土与有机物的相容性,采用十六烷基三甲基溴化铵(CTAB)与硅烷偶联剂(KH-560)对蒙脱土进行了有机复合改性。X-射线衍射和红外光谱的结果表明,CTAB已插入蒙脱土片层,平均层间距离从1.54 nm增大到3.98 nm和2.08 nm,而KH-560未插入蒙脱土片层,只是覆盖在蒙脱土表面,未改变蒙脱土的插层结构;分散性实验表明,表面活性剂和硅烷偶联剂有机复合改性的蒙脱土在苯乙烯、液体石蜡中的分散性好于其他改性蒙脱土;有机复合改性不仅增大了蒙脱土层间距,且改善了蒙脱土与聚氯乙烯的界面效果,提高了蒙脱土在聚氯乙烯基体中的分散均匀性,从而使聚氯乙烯/蒙脱土复合材料玻璃化转变温度的提高和力学性能的改善更明显。     

制备聚丙烯酸钠分散剂的最佳工艺条件探究

以丙烯酸为单体,采用过硫酸铵和亚硫酸氢钠为氧化还原引发剂,同时亚硫酸氢钠又作为链转移剂来制备低分子量的聚丙烯酸钠。研究了单体浓度、引发剂用量、链转移剂用量以及反应温度对分子量和分散性的影响。通过正交设计实验确定了最佳反应条件:过硫酸铵用量为 5 56%,亚硫酸氢钠为 4 44%,单体浓度为 33 3%,温度 70℃,反应时间为 3h。     

MA-AM-AA三元共聚物的制备及阻垢性能

以马来酸酐(MA)、丙烯酸(AA)和丙烯酰胺(AM)为原料,研制出环保型三元共聚阻垢剂PMAA,并通过研究其阻垢性能确定了产品的最佳工艺配方。实验结果表明,当单体的质量配比m(AA)∶m(AM)∶m(MA)=2∶3∶0·5,引发剂用量为单体总质量的1.5%,反应温度为80℃,单体质量分数为15%时,得到的聚合物PMAA的用量为5mg/L时,用国标法测得其对碳酸钙的阻垢率达94·15%,对磷酸钙的阻垢率达80·93%。     

煤热解工艺中挥发分除尘技术的现状分析及建议

针对粉煤热解多联产工艺中热解挥发分除尘的技术难题,阐述了热解挥发分所含粉焦及煤灰颗粒的特性、热解工艺对除尘器的要求,对热解挥发分除尘技术的研究现状进行分析并提出建议,认为煤热解工艺中挥发分除尘技术应该从热解工艺本身出发,采用加氢(催化)热解方式,促进热解气中重质焦油组分裂解,使热解产物轻质化,从而降低煤热解挥发分的除尘难度。此外,可以采用多种除尘设备有机组合的方式并辅以分离前对细小粉尘进行预团聚等手段,强化除尘效果、提高煤热解工艺中挥发分的除尘效率。     

大颗粒吸水树脂的制备工艺及其性能

采用反相悬浮聚合制备了大颗粒聚丙烯酰胺-丙烯酸-丙烯酸钠[P(AM-AA-SA)]树脂微球,考察了搅拌速率与乳化剂对树脂微球粒径的影响,交联剂用量、单体配比和丙烯酸中和度对330μm树脂微球吸水倍率的影响,丙烯酸丁酯的用量对树脂吸水速率的影响以及树脂微球在80℃下的保水性能.结果表明:制备的树脂吸去离子水量达983.0 g/g,对NaCl和CaCl2溶液的吸水倍率最大值分别为91 3,15.6 g/g,在80℃下有良好的保水性能,丙烯酸丁酯的加入可将吸水饱和时间延长2倍.