白炭黑改性及其在橡胶中的应用研究进展

介绍白炭黑改性及其在橡胶中的应用研究进展。通过白炭黑表面接枝改性和偶联剂改性以及白炭黑与其它填料插层复配,可增强白炭黑与橡胶间的相互作用,改进白炭黑的补强效果。白炭黑用于天然橡胶、顺丁橡胶、丁苯橡胶、三元乙丙橡胶等中,胶料网络结构增强,物理性能和抗湿滑性能改善,滚动阻力降低。未来白炭黑研究应集中在白炭黑的界面属性方面,以进一步发挥白炭黑作为补强填料的优势。     

表面活性剂在橡胶中的应用

从胶乳方面的应用和对无机填料的改性2个方面对近年来表面活性剂在橡胶中的应用进行了总结,目前主要研究方向集中在对无机填料的改性方面。无机填料经过适当改性,可以解决其易团聚、难分散、与橡胶相容性差等问题,从而更好地与橡胶结合达到更好的补强效果。重点介绍了表面活性剂对无机填料的改性。     

煤炭资源类填充剂在橡胶中的应用进展

介绍了高硫煤、煤矸石、粉煤灰和石煤渣等煤炭资源类填充剂经粉碎、表面改性后在橡胶中的应用,以及制备炭黑、白炭黑后应用于橡胶中的进展。煤炭资源的废弃物多为无机材料,对其表面改性以增强其与橡胶的相容性就显得极其重要。煤炭资源类填充剂的利用具有经济、社会和环境的三位一体的效益。     

工业铝灰作为铝质校正原料在熟料煅烧中的应用

0引言 工业铝灰是电解铝或铸造铝生产工艺中产生的熔渣经冷却加工后的副产品,人们通常把工业铝灰当作废渣而堆弃,寻找经济有效的方法加以利用和治理工业铝灰,不仅可以实现资源的有效循环利用,还将对实现经济、社会的可持续发展产生重要的影响.我公司将工业铝灰在水泥企业的开发利用作为一个重要课题进行试验研究,并进行推广利用,取得了较...     

纤维织物在我国胶鞋工业中的应用

胶鞋是橡胶工业最早的产品之一,也是我国橡胶工业中起源最早、历史最久的传统产品。我国自1917年广东出现第一家胶鞋厂到1997年已成为世界上最大的胶鞋生产国和出口国,胶鞋花式品种累计已达千余种。据国家统计局统计,2002年胶鞋总产量已达9.59亿双,民间根据内销和出品量估计实际上应为15亿双左右。胶鞋按材料可分为布面胶鞋、胶面胶鞋和橡塑鞋三类。布面胶鞋鞋帮取材于纺织物,配上围条、大底、中底和前包头等胶制部件;胶面胶鞋整个统面取材于覆贴胶面的棉毛针织物,具有不渗漏的功能;橡塑鞋底材采用纯胶或橡塑共混物、热塑性弹性体,帮材采用…     

Application of rice husk ash as fillers in the natural rubber industry

Rice husk ash (RHA) obtained from agricultural waste, by using rice husk as a power source, is mainly composed of silica and carbon black. A two‐stage conventional mixing procedure was used to incorporate rice husk ash into natural rubber. For comparison purposes, two commercial reinforcing fillers, silica and carbon black, were also used. The effect of these fillers on cure characteristics and mechanical properties of natural rubber materials at various loadings, ranging from 0 to 40 phr, was investigated. The results indicated that RHA filler resulted in lower Mooney viscosity and shorter cure time of the natural rubber materials. The incorporation of RHA into natural rubber improved hardness but decreased tensile strength and tear strength. Other properties, such as Young's modulus and abrasion loss, show no significant change. However, RHA is characterized by a better resilience property than that of silica and carbon black. Scanning electron micrographs revealed that the dispersion of RHA filler in the rubber matrix is discontinuous, which in turn generates a weak structure compared with that of carbon black and silica. Overall results indicate that RHA can be used as a cheaper filler for natural rubber materials where improved mechanical properties are not critical. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 34–41, 2005     

Reactivity of rice husk ash

Effect of lime:silica ratio on the kinetics of the reaction of silica with saturated lime has been investigated. Below C/S=0.65 the reaction does not proceed to completion and even in the presence of a large excess of silica only 90% lime is consumed. A parameter, lime reactivity index, has been defined to quantity the reactive silica present in rice husk ash. The product of the reaction between rice husk ash and saturated lime is a calcium hydrosilicate, CSH(I)⁷. The fibrilar structure and the hollow tubular morphology of the fibres of CSH, have been explained by a growth mechanism, where the driving force is osmotic pressure.     

由稻壳灰制备的新型硅环氧化合物改性白炭黑增强硅橡胶的性能

用直接从稻壳灰制备的硅环氧化合物(SiE)改性白炭黑增强硅橡胶。结果表明:SiE的加入可显著提高硅橡胶的性能,当其用量为4份时,硅橡胶的综合性能最佳,撕裂强度、拉伸强度及扯断伸长率分别为12.6 kN/m,6.4 MPa和500％,比未改性的分别提高了32.6％,33.3％和31.6％;同时胶料的加工工艺性能亦有很大改善。     

稻壳灰纳米白炭黑对天然橡胶复合材料性能的影响

利用稻壳灰通过溶胶-凝胶法制备稻壳灰纳米白炭黑,采用傅里叶变换红外光谱、X射线衍射谱和扫描电子显微镜法分析稻壳灰纳米白炭黑的微观结构、组成和粒径,研究其作为填料对天然橡胶（NR）复合材料性能的影响,并与高分散性白炭黑Z1165MP和175MP进行对比。结果表明：制备的稻壳灰纳米白炭黑的纯度较高,平均粒径为40～60 nm;与白炭黑Z1165MP和175MP相比,稻壳灰纳米白炭黑在NR基体中的分散性较好,填充稻壳灰纳米白炭黑的NR混炼胶t10和t90延长,硫化胶的拉伸强度较高,0 ℃时的tanδ较大,综合性能明显提高。     

Pastes of tricalcium silicate with rice husk ash

Pastes of tricalcium silicate with rice husk ash (RHA) were cured at 25°C for 1–245 days and examined by XRD, analytical electron microscopy, TG, acid extractions to determine unreacted rice husk ash, and trimethylsilylation. The rice husk ash was highly reactive, and contents of calcium hydroxide, referred to the ignited weight, never exceeded 3%. Initially, a product having a Ca/Si atom ratio of 0.1–0.2 was formed, but this was later replaced by one having a Ca/Si ratio of approximately 1.3. The proportion of the Si in the hydration products that was present as polymeric ions was greater than that found in pure C₃S or C₃S-fly ash pastes of similar age, but the anion size distributions within the polymer were all broadly similar.     

Use of rice husk ash as filler in natural rubber vulcanizates: In comparison with other commercial fillers

Rice husk ash is mainly composed of silica and carbon black remaining from incomplete combustion. Both silica and carbon black have long been recognized as the main reinforcing fillers used in the rubber industry to enhance certain properties of rubber vulcanizates, such as modulus and tensile strength. In this study, two grades of rice husk ash (low‐ and high‐carbon contents) were used as filler in natural rubber. Comparison was made of the reinforcing effect between rice husk ashes and other commercial fillers such as talcum, china clay, calcium carbonate, silica, and carbon black. Fourier transform infrared spectroscopy (FTIR) analysis was employed to study the presence of functional groups on the ash surface. The effect of silane coupling agent, bis(3‐triethoxysilylpropyl)tetrasulfane (Si‐69), on the properties of ash‐filled vulcanizates was also investigated. It was found that both grades of rice husk ash provide inferior mechanical properties (tensile strength, modulus, hardness, abrasion resistance, and tear strength) in comparison with reinforcing fillers such as silica and carbon black. However, the mechanical properties of the vulcanizates filled with rice husk ash are comparable to those filled with inert fillers. The addition of silane‐coupling agent has little effect on the properties of the ash‐filled vulcanizates. This is simply due to the lack of silanol groups on the ash surface. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2485–2493, 2002     

Characterizing pozzolanic activity of rice husk ash by impedance spectroscopy

Rice husk ash (RHA) has long been known to possess a pozzolanic property. The abundance of rice husk as agricultural waste makes RHA the most promising candidate to be used as a supplementary cementitious material (SCM) in many rice-exporting countries. The use of RHA as an SCM helps reduce the use and thus the production of cement that involves great energy consumption and CO₂ emission. To promote the use of RHA as an SCM, a method to assess its pozzolanic activity is needed for the process of optimizing the burning conditions and/or selecting RHA from uncontrolled burning of rice husk as biomass fuel.The present work aims to use impedance spectroscopy to characterize pozzolanic activity of RHAs prepared on a pilot scale. The method is based on the rate of the normalized conductivity change of the Ca(OH)₂ + RHA paste, d(σ/σ₀)/dt, during the first 24 h of hydration. The measurement was found to be sensitive to the unburnt carbon content in the 6–8 wt.% range and the amorphous SiO₂ content (regardless of the unburnt carbon content). When used to evaluate two separate groups of RHAs, each with comparable unburnt carbon contents, the method gives very high correlation coefficients to the strength activity index at 3, 7, and 28 days. However, the correlation coefficients fall significantly when RHAs with vast difference in the unburnt carbon contents are considered together. The method thus proves to be powerful for evaluation of the pozzolanic activity of RHAs with comparable carbon contents.     

Competitive adsorption of phenol and resorcinol onto rice husk ash

The present study deals with the adsorptive removal of phenol and resorcinol from aqueous solution onto rice husk ash. The competitive adsorption equilibrium of the binary mixtures (phenol/resorcinol) was determined by conducting batch experiments with initial concentration varying in the range of 50 to 1000 mg/L. In order to evaluate multicomponent adsorption isotherm parameters, individual adsorption equilibrium studies were also carried out. Langmuir, Freundlich and Redlich-Peterson equilibrium isotherm models were used for single compound equilibrium sorption data modeling. All three models almost similar fit for single compound equilibrium data. Binary equilibrium adsorption data and the parameter evaluated from single adsorption data were fitted to various multicomponent isotherm models by minimizing the sum of square of error. The extended Langmuir model gave the better fit to the experimental adsorption data of phenol and resorcinol from binary systems onto rice husk ash. It seems that both phenol and resorcinol compete for the same adsorption sites on rice husk ash. The net interactive effect of phenol and resorcinol on the adsorption of resorcinol by rice husk ash was found to be antagonistic.     

Reaction product of lime and silica from rice husk ash

Rice husk ash (about 95% silica) with known physical and chemical characteristics has been reacted with lime and water. The setting process for a lime-excess and a lime-deficient mixture has been investigated. The product of the reaction has been shown to be a calcium silicate hydrate, C-S-H(I)⁺ by a combination of thermal analysis, XRD and electron microscopy. Formation of C-S-H(I) accounts for the strength of lime-rice husk ash cement.     

稻壳灰建材资源化的研究进展

稻壳灰是工业中稻壳作为生物燃料煅烧后的残留废弃物,利用稻壳灰生产建筑材料是其资源化的有效途径;简单介绍了稻壳灰的组成和烧制工艺,重点介绍了稻壳灰建材资源化的研究进展,尤其是稻壳灰在水泥、混凝土中的最新研究成果,以及稻壳灰在砂浆、砌块和保温建材中的应用;指出了稻壳灰建材资源化中存在的问题,需要进一步探索研究来更好的利用稻壳灰资源。