AC发泡剂的改性

本文分四个主要方面来叙述AC发泡剂的改性。其改性目的在于扩大应用领域,增加新品种,优化发泡制品以及加速AC产品系列化。     

改性AC发泡剂对PVC木塑复合材料力学性能影响

采用动态热流式差示扫描量热仪对自制改性偶氮二甲酰胺(AC)发泡剂进行了分析,并研究了其用量对聚氯乙烯（PVC）木塑复合材料力学性能的影响。结果表明,该改性AC发泡剂的分解温度在165~187 ℃,与传统AC发泡剂相比分解温度降低约40 ℃,且峰值放热量降低了39.5 ％;改性AC发泡剂的平均发气量为189 mL/mg;扫描电子显微镜分析表明,使用1.2份改性AC发泡剂时获得的PVC木塑复合材料的泡孔致密均匀,明显优于使用未改性AC发泡剂的情况;与未发泡的材料相比,使用1.2份改性AC发泡剂时, PVC木塑复合材料的冲击强度提高了34.6 %,表观密度降低了22.5 ％。     

改性AC发泡剂对PVC木塑复合材料性能影响

采用动态热流式差示扫描量热仪对自制改性偶氮二甲酰胺(AC)发泡剂进行了分析,并研究了其用量对聚氯乙烯(PVC)木塑复合材料力学性能的影响。结果表明,该改性AC发泡剂的分解温度在165~187℃,与传统AC发泡剂相比,分解温度降低约40℃,且峰值放热量降低了39.5%;改性AC发泡剂的平均发气量为189 mL/mg;扫描电子显微镜分析表明,添加1.2份改性AC发泡剂时获得的PVC木塑复合材料的泡孔致密均匀,明显优于未改性的;与未发泡的材料相比,添加1.2份改性AC发泡剂时,PVC木塑复合材料的冲击强度提高了34.6%,表观密度降低了22.5%。     

改性AC对EPDM海绵橡胶结构及发泡特性的影响

以三元乙丙橡胶(EPDM)为基胶,二氧化硅为成核剂,对比探究了二氧化硅化学改性发泡剂AC和物理改性发泡剂AC对EPDM发泡材料性能的影响。结果表明,引入成核剂可使EPDM发泡材料泡孔均匀性变好,尺寸更加均一;化学改性发泡剂优于物理改性发泡剂。     

SBR高发泡海绵的制备与性能研究

以SBR为基本原料,添加硼酸酯偶联剂改性陶土、环烷油、苯二磺酰肼/AC复合发泡剂等助剂,采用硫化发泡方法制备SBR高发泡海绵,并对其性能进行研究.结果表明,改性陶土能够增大SBR海绵胶粘度,减缓硫化速率;环烷油能够延长正硫化时间.添加30份改性陶土和3.5份环烷油的SBR海绵具有密度低、柔软度好、弹性高和缓冲减震性能好等特点.     

浅谈AC发泡剂的工艺改进

介绍了AC生产过程和降低AC生产成本的一些措施以及AC的改性等。     

发泡剂ADC改性的研究现状和发展趋势

系统地概述了近几十年来国内外对发泡剂ADC进行改性的研究状况,并探讨了未来发泡剂ADC改性研究的发展趋势.     

氨水改性玉米秸秆活性炭处理间苯二酚胶粘剂废水的研究

采用氨水改性AC(玉米秸秆活性炭),并对改性AC的表面特性及吸附胶粘剂废水的吸附效果进行了探讨。研究结果表明:经15%氨水浸渍8h后,AC的孔隙结构变得更为发达,从而更有利于提升其吸附效果;改性AC对胶粘剂废水表现出很强的吸附能力,其最大吸附容量为44.58mg/g;改性AC对胶粘剂废水的吸附符合Freundlich吸附类型。     

AC发泡剂的改性

通过添加氧化锌，过氧化锌等化学品，对ＡＣ发泡剂进行改性。     

AC发泡剂生产工艺的探讨

本文介绍了AC发泡剂的生产工艺:氯法、氯酸盐法、双氧水法、氯与氯酸盐结合氧化法,并对不同工艺下的AC收率进行探讨。其中以氯与氯酸盐结合氧化法为最好,该工艺在我国目前情况下值得推广。     

Modified activated carbon with an enhanced nitrobenzene adsorption capacity

To enhance nitrobenzene removal from aqueous solution, commercial activated carbon (AC) was modified by oxidation with HNO₃ followed by heat treatment in a nitrogen atmosphere. The modification process introduced oxygen-containing functional groups and changed the charge properties of the AC surface. The effects of surface chemical properties and pore structure on the adsorption of nitrobenzene by the AC were investigated through kinetics and equilibrium isotherms. HNO₃ oxidation modified the surface chemical properties and increased the number of acidic oxygen-containing surface groups, but had an almost negligible effect on the pore structure. Subsequent heat treatment caused decomposition of oxygen-containing functional groups on the AC surface, increased the pH point of zero charge (pH_PZC) and increased the number of mesopores. The maximum adsorption capacity achieved by the modified AC was 1,443.53 mg g^?1, 3.33 times of that unmodified AC. HNO₃ oxidation combined with heat treatment was an effective method for the preparation of AC with high nitrobenzene adsorption capacity and fast adsorption kinetics. An appropriate pH_PZC, amount of surface oxygen groups and the presence of well-developed mesopores together with micropores were the main reasons for the high nitrobenzene adsorption capacity of the modified AC.     

Behavior of phenol adsorption on thermal modified activated carbon

Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon(AC) samples after thermal modification were prepared by using muffle furnace. The phenol adsorption kinetics and equilibrium measurements were carried out under static conditions at temperature ranging from 25 to 55 °C. The test results show that the thermal modification can enhance phenol adsorption on AC samples. The porous structure and surface chemistry analyses indicate that the decay in pore morphology and decrease of total oxygen-containing functional groups are found for the thermal modified AC samples. Thus, it can be further inferred that the decrease of total oxygen-containing functional groups on the modified AC samples is the main reason for the enhanced phenol adsorption capacity. For both the raw sample and the optimum modified AC sample at 900 °C, the pseudo-second order kinetics and Langmuir models are found to fit the experimental data very well. The maximum phenol adsorption capacity of the optimum modified AC sample can reach144.93 mg·g-1which is higher than that of the raw sample, i.e. 119.53 mg·g-1. Adsorption thermodynamics analysis confirms that the phenol adsorption on the optimum modified AC sample is an exothermic process and mainly via physical adsorption.     

Synthesis of novel acrylic modified water reducible alkyd resin: Investigation of acrylic copolymer ratio effect on film properties and thermal behaviors

New four‐component water reducible acrylic modified alkyd resins that are based on 1,3‐propanediol and contain different ratios of acrylic copolymer (AC) were synthesized by using a novel four‐stage fatty acid method. The final content of solids in the water reducible acrylic modified alkyd resins was 60% by weight. After the modified alkyd resin films were cured at 150°C for 1 h, it was observed that the use of AC as the modifier component had improved their physical and chemical surface coating properties and thermal behaviors. Experimental results show that the optimum AC ratio is 40% of the equivalent amount of AC to alkyd resin. Low‐volatile organic compounds (VOC) content water reducible acrylic modified alkyd resins yielded soft and flexible films with high chemical/thermal resistance, suitable for manufacturing of surface coating binders. POLYM. ENG. SCI., 56:947–954, 2016. © 2016 Society of Plastics Engineers     

活性炭改性对卷烟烟气中VOCs吸附效率的影响

为研究改性活性炭对主流烟气中挥发性有机物（ VOCs）吸附效率的影响,将HCl、 H2 O2、 HNO3、 NaOH和丙酮改性的活性炭添加到滤嘴中,并采用GC-MS方法检测主流烟气中5种主要VOCs的释放量。结果表明：①活性炭对主流烟气中VOCs有较高的吸附效率;②滤嘴中活性炭的最佳添加量为30 mg;③活性炭对VOCs的吸附效率随VOCs分子量和沸点的升高而呈升高趋势;④不同方法改性的活性炭对卷烟主流烟气中VOCs的吸附效率不同, HCl改性活性炭吸附效率最理想;⑤影响活性炭对VOCs吸附效率的最主要因素是其比表面积,但其他因素,如微孔孔容、微孔率、 pH值等也会对活性炭的吸附效率产生影响。     

Removal of low-concentration formaldehyde in air by adsorption on activated carbon modified by hexamethylene diamine

Activated carbon (AC) was modified by hexamethylene diamine (HMDA) to remove low-concentration formaldehyde in air. Results demonstrate that no ammonia or amine compounds give out from the modified AC up to 423 K. And the modification significantly improves the adsorption performance of AC for formaldehyde. There exists an optimum loading amount, being around 0.04 g HMDA/g AC in this study.     

The examination of surface chemistry and porosity of carbon nanostructured adsorbents for 1-naphthol removal from petrochemical wastewater streams

Chemically modified mesoporous carbon (CMMC) and chemically modified activated carbon (CMAC) were prepared by an acid surface modification method from mesoporous carbon (MC) and commercial activated carbon (AC) by wet impregnation method. The structural order and textural properties of the nanoporous materials were studied by XRD and nitrogen adsorption. The presence of carboxylic functional groups on the carbon surface was confirmed by FTIR analyses. Adsorption of 1-naphthol over various porous adsorbents such as CMMC, CMAC, MC and AC was studied. The adsorption isotherms of 1-naphthol were in agreement with a Langmuir model; moreover, the uptake capacity of 1-naphthol followed the order: CMMC>MC>CMAC>AC.     

Enhancement of the denitrification efficiency over low-rank activated coke by doping with transition metal oxides

Low-rank activated coke (AC) is widely used for industrial flue gas purification due to its multipollutant cooperative removal capability. To enhance the denitrification capacity of AC for the selective catalytic reduction (SCR) of NO with NH₃, several transition metal (Fe, Mn, Ce, V) oxides were uniformly loaded into AC by solvent impregnation. Compared to untreated AC, modified AC showed excellent denitrification efficiency above 90%. N₂ adsorption-desorption and Raman spectroscopy techniques were used to characterize the pore size distribution and crystal structure of AC samples. The introduction of transition metal oxides had little effect on the pore structure of AC but increased the nitrogen-containing functional groups, which facilitated NO removal. Moreover, x-ray photoelectron spectroscopy (XPS) was used to analyze the valence changes of metal elements before and after denitrification. After the reaction, the content increase of the low-valence metal oxides indicated that the transition metal oxides were involved in the reaction of NO with NH₃. High-valence metal oxides oxidized NO to NO₂, which reacts more easily with NH₃, thereby increasing the denitrification efficiency. Importantly, in the presence of SO₂, modified AC still presented high denitrification performance. This transition metal oxides doping method can effectively improve the ability of low-rank AC to remove NO in multi-contaminant flue gas.     

Implantation of amino functionality into amorphous carbon sheet surfaces by NH3 plasma

Amorphous carbon (AC) sheet surfaces were modified with ammonia (NH₃) plasma in order to form primary amino groups on AC surfaces. The NH₃ plasma modification formed both nitrogen- and oxygen-containing groups on the AC sheet surfaces, and the contact angle of water against the modified AC surfaces decreased from 76° to 64°-56°. The formation of primary amino groups preferred NH₃ plasma operated at a low rf power (5-10 W) to that at a high power. The concentration of primary amino groups was strongly influenced by how much rf power the NH₃ plasma was operated. The NH₃ plasma operated at 10 W was a preferable condition for the formation of primary amino groups on the AC sheet surfaces, and their concentration was 1.3-1.4 N(amino)-atoms/100 C-atoms.     

The adsorption and desorption characteristics of a binary component system of toluene and methylethylketone on activated carbon modified with phosphoric acid

As adsorption characteristics, breakthrough curve and adsorption capacity were investigated using a flow-typed fixed-bed adsorption system for single or binary component, mixed gas systems of toluene and methylethylketone (MEK) on activated carbon (AC) modified with phosphoric acid (PA). In the results, the amount of toluene and MEK adsorbed on the PA modified AC (PA/AC) was larger than that on the purified AC. The breakthrough curve of the key component (toluene) was sigmoidal in the binary components. However, the breakthrough curve of the non-key component (MEK) exhibited the roll-up phenomenon, which was entirely different from the single component adsorption process because of the competitive adsorption of the key component. After passing a stream of toluene over the MEK adsorbed PA/AC, almost all of the MEK was easily substituted with toluene and desorbed at 25 °C. Therefore, the roll-up of MEK was attributed to its lower adsorption intensity than toluene.