蒙脱土纳米复合材料作为成碳剂的热氧化分解动力学研究

采用蒙脱土纳米复合材料与高聚磷酸铵(APP)组成的阻燃体系对棉织物进行阻燃整理,并用非等温热重分析方法对复合阻燃体系整理后棉织物的热氧化分解特性进行研究.在空气气氛下,以不同的升温速率将样品从室温加热至900℃.通过基于动力学补偿效应的恒定动力学参数(IKP)法计算整理后织物的非等温氧化分解动力学参数,并由IKP法求得常用固相机理函数概率分布,确定复合体系的动力学模型.最终确定整理后织物的热氧化分解过程可由成核和核增长以及幂级反应机理函数进行描述.

一种含生物基成碳剂的阻燃聚丙烯材料及其制备方法

本发明属于高分子材料技术领域,具体公开了一种含生物基成碳剂的阻燃聚丙烯及其制备方法。含生物基成碳剂的阻燃聚丙烯的配方为:聚丙烯70phr,聚磷酸铵18phr,生物基成碳剂与季戊四醇总量为12phr,两者质量比为1.0∶(1.5~3.0)。采用本发明制备的含生物基成碳剂的阻燃聚丙烯具有阻燃性能好,成碳剂可再生,价格低廉,生产工艺简单,易于工业化,符合材料的可持续发展趋势。

生物质阻燃剂对聚丙烯的性能影响研究

以MPP为脱水剂和发泡剂,魔芋飞粉为成碳剂,膨胀石墨为协效剂组成了新型的膨胀型阻燃剂,应用到聚丙烯中制备出了聚丙烯阻燃材料,并对其阻燃及力学性能进行了系统研究。结果表明魔芋飞粉的存在对聚丙烯阻燃材料的力学性能稍有改善,但对其阻燃性能改善不太明显,这可能是由于魔芋飞粉中存在的大量小分子有机物反而促进了聚丙烯的燃烧。

金属化合物对新型膨胀阻燃LDPE的协同作用

以新型的齐聚物式成碳剂(OCA)与多聚磷酸铵(APP)复配成新型膨胀型阻燃剂(IFR),采用氧指数测定仪(LOI)、垂直燃烧测定仪(UL)、热重分析仪(TGA)和红外光谱(FTIR)研究了碳酸镍(NC)、硼酸锌(ZB)和二氧化锰(MnO2)与LDPE/IFR体系的阻燃协同作用。结果表明:添加1%的金属化合物后,复合材料的氧指数值都有一定程度的提高,其中NC的效果最佳。TGA分析结果表明:金属化合物都能促使复合材料提前分解成碳,NC还能保留更多的残碳。FTIR分析表明:残碳中形成了聚芳烃和P-O-C、P-O-P的交联结构。

无卤膨胀型阻燃聚乙烯的性能研制

选择自制碳源、酸源、气源与一体的阻燃剂B-1，螺环类阻燃剂-PEPA及具有酸源和气源的多聚磷酸铵（APP）为基本阻燃元素进行配方设计，考察了不同成碳剂品种（A1、A2、A3、A4、A5）及用量对阻燃效果的影响。试验结果表明：PEPA与APP复配具有很好的阻燃效果，当PEPA/APP配比在60-40/40-60范围内，成碳剂A1加入量为1.0%，阻燃剂总添加量为30%时达到UL-94V-0标准，通过优化偶联剂的品种和用量，使膨胀型阻燃聚乙烯在拥有阻燃效果的同时具有优良的力学性能及加工性能。

协同阻燃氯丁橡胶的无焰燃烧与阻燃性能

利用氧指数(LOI)和锥形量热仪(CONE)探讨了微胶囊化红磷(MRP)、成碳剂(CTJ)、化学膨胀剂(IFR)复合阻燃氯丁橡胶的协同效应,通过热失重分析(TG)研究了阻燃氯丁橡胶的热失重行为。结果表明,当三者共用10份,且MRP:CTJ:IFR为3:1:1时,阻燃氯丁橡胶体系的阴燃时间为4s,同时LOI达到了44%;热释放速率只有纯CR的50%;生烟速率为纯CR的1/3,表现出一定的协同作用;在空气气氛下,三者相互促进形成碳层,抑制热释放、延长失重时间。

阻燃氯丁橡胶的无焰燃烧与阻燃性能

将十溴二苯乙烷(DBDPE)、成碳剂(CTJ)、化学膨胀剂(IFR)复配阻燃氯丁橡胶,利用氧指数(LOI)和锥形量热仪(CONE)探讨了十溴二苯乙烷与CTJ、IFR复配阻燃氯丁橡胶的协同效应,通过扫描电镜研究表征样品的断面形貌。结果表明,当三者共用15份,且DBDPE∶CTJ∶IFR比例为7:2:6时,阻燃CR体系的无焰燃烧时间为7 s,同时LOI达到了4 0%,热释放速率只有纯C R的11.4%,生烟速率为纯C R的3 0.8%,表现出一定的协同作用;从样品燃烧后的断面扫描电镜照片看出,兼有了物理成炭和化学成炭的优点,提高了阻燃性能。

膨胀封堵型防火复合材料的研制

以热膨胀聚合物为基料,添加阻燃剂、燃烧发泡剂、成碳剂、增充剂、增强剂等助剂,制备了膨胀型封堵防火材料。实验结果表明,使用浇注工艺制得的材料制品,燃烧膨胀率达到16,材料的氧指数达到66,燃烧发烟量很少。

钢结构用防火粉末涂料的研制

介绍了钢结构用防火粉末涂料的配方及性能;探讨了树脂、发泡剂、成碳剂、阻燃剂的用量对防火性能的影响。

Effects of zinc on Fe-based catalysts during the synthesis of light olefins from the Fischer-Tropsch process

Fe‐based catalysts for the production of light olefins via the Fischer‐Tropsch synthesis were modi‐fied by adding a Zn promoter using both microwave‐hydrothermal and impregnation methods. The physicochemical properties of the resulting catalysts were determined by scanning electron mi‐croscopy, the Brunauer‐Emmett‐Teller method, X‐ray diffraction, H2 temperature‐programed re‐duction and X‐ray photoelectron spectroscopy. The results demonstrate that the addition of a Zn promoter improves both the light olefin selectivity over the catalyst and the catalyst stability. The catalysts prepared via the impregnation method, which contain greater quantities of surface ZnO, exhibit severe carbon deposition following activity trials. In contrast, those materials synthesized using the microwave‐hydrothermal approach show improved dispersion of Zn and Fe phases and decreased carbon deposition, and so exhibit better CO conversion and stability.

水性饰面型防火涂料的研制

介绍水性饰面型防火涂料的防火机理及阻燃体系的确定 ,涂料成膜基料、膨胀催化剂、发泡剂、成碳剂、颜填料及助剂等的选用 ,通过正交试验 ,确定防火涂料最佳配方。

On the role of cobalt carbidization in higher alcohol synthesis over hydrotalcite-based Co-Cu catalysts

Co-Cu-based catalysts are widely applied in higher alcohol synthesis (HAS) from synthesis gas. Although the nature of the active sites is still not fully understood, the formation of Co2C under HAS conditions seems to play a major role. A CO pretreatment procedure was developed allowing a systematic investigation of the influence of cobalt carbidization on the structural properties and catalytic performance of the catalysts. By exposing the catalyst to a CO-containing atmosphere prior to HAS, Co enrichment of the catalyst surface occurred followed by carbide formation. This surface modification decreased the formation of hydrocarbons and enhanced the formation of C2+OH. The catalyst pretreated with CO at 20 bar achieved the highest selectivity to ethanol and the lowest hydrocarbon selectivity.

Current status and future development of solvent-based carbon capture

Solvent-based carbon capture is the most commercially-ready technology for economically and sustainably reaching carbon emission reduction targets in the power sector. Globally, the technology has been deployed to deal with flue gases from large scale power plants and different carbon-intensive industries. The success of the technology is due to significant R＆D activities on the process development and decades of industrial experience on acid gas removal processes from gaseous mixtures. In this paper, current status of PCC based on chemical absorption--commercial deployment and demonstration projects, analysis of different solvents and process configurations--is reviewed. Although some successes have been recorded in developing this technology, its commercialization has been generally slow as evidenced in the cancellation of high profile projects across the world. This is partly due to the huge cost burden of the technology and unpredictable government policies. Different research directions, namely new process development involving process intensification, new solvent development and a combination of both, are discussed in this paper as possible pathways for reducing the huge cost of the technology.

Preliminary Study on the Characteristics of Isotactic Polypropylene with Nucleating Agent Swollen by Supercritical Carbon Dioxide

Impregnation of isotactic polypropylene (iPP) with nucleating agent (NA21) using supercritical carbon dioxide as the swelling agent at different temperature and pressure and its non-isothermal crystallization kinetics were investigated. The results showed that NA21 was dispersed at a nanometer-scale in the PP matrix, resulting in the formation of different typesof crystal phases of iPP and the enhancement of its mechanical properties.

Zn–Ca–Al mixed oxide as efficient catalyst for synthesis of propylene carbonate from urea and 1,2-propylene glycol

A series of Zn–Ca–Al oxides with different CaO and ZnO contents have been prepared and evaluated in the synthesis of propylene carbonate(PC) from 1,2-propylene glycol(PG) and urea in a batch reactor. The effect of catalyst composition, basicity and reaction process parameters such as temperature, catalyst dose, molar ratio of PG to urea, purge gas flow and reaction time has been studied to find suitable reaction conditions for the PC synthesis. The PC selectivity and yield under the desired conditions could reach 98.4% and 90.8%, respectively. The best performing catalyst also exhibited a good reusability without appreciable loss in the PC selectivity and yield after five consecutive reaction runs. In addition, a stepwise reaction pathway involving a 2-hydroxypropyl carbamate intermediate was proposed for the urea alcoholysis to PC in the presence of Zn–Ca–Al catalysts, according to the time dependences of reaction intermediates and products.

Highlights of the major progress in single-atom catalysis in 2015 and 2016

The idea that single metal atoms dispersed on a solid support can act as an efficient heterogeneous catalyst was raised in2011when single Pt atoms on an FeOx surface were reported to be active for CO oxidation and preferential oxidation of CO in H2.The last six years have witnessed tremendous progress in the field of single‐atom catalysis.Here we introduce the major achievements on this topic in2015and2016.Some particular aspects of single‐atom catalysis are discussed in depth,including new approaches in single‐atom catalyst(SAC)synthesis,stable gold SACs for various reactions,the high selectivity of Pt and Pd SACs in hydrogenation,and the superior performance of non‐noble metal SACs in electrochemistry.These accomplishments will encourage more efforts by researchers to achieve the controllable fabrication of SACs and explore their potential applications.

Review on current advances,future challenges and consideration issues for post-combustion CO_2 capture using amine-based absorbents

Among the current technologies for post-combustion CO2 capture,amine-based chemical absorption appears to be the most technologically mature and commercially viable method.This review highlights the opportunities and challenges in post-combustion CO2 capture using amine-based chemical absorption technologies.In addition,this review provides current types and emerging trends for chemical solvents.The issues and performance of amine solvents are reviewed and addressed in terms of thermodynamics,kinetics,mass transfer,regeneration and solvent management.This review also looks at emerging and future trends in post-combustion CO2 capture using chemical solvents in the near to mid-term.

Study on Direct Synthesis of Diphenyl Carbonate with Heterogeneous Catalytic Reaction (V) Screening Catalysts and Optimizing Synthesis Conditions

Pd/LaxPbyMnOz, Pd/C, Pd/molecular sieve and Pd-heteropoly acid catalysts for direct synthesis of diphenyl carbonate (DPC) by heterogeneous catalytic reaction were compared and the results of DPC synthesis indicated that the catalyst Pd/LaxPbyMnOz had higher activity. The Pd/LaxPbyMnOz catalyst and the support was characterized by XRD, SEM and TEM, the main phase was Lao.szPbo.asMnOa and the average diameter could be about 25.4nm. The optimuna conditions for synthesis of DPC with Pd/LasPbyMnOz were determined by orthogonal experiments and the experimental results showed that reaction temperature was the first factor of effect on the selectivity and yield of DPC, and the concentration of O2 in gas phase also had significant effect on selectivity of DPC. The optimum reaction conditions were catalyst/phenol mass ratio l to 50, pressure 4.5MPa, volume concentration of O2 25%, reaction temperature 60℃ and reaction time 4 h. The maximum yield and average selectivity could reach 13% and 97% respectively in the batch operation.

Synthesis of acetals and ketals catalyzed by tungstosilicic acid supported on active carbon

Catalytic activity of activated carbon supported tungstosilicic acidin synthesizing 2-methyl-2-ethoxycarbonylmethyl- 1,3-dioxolane, 2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane, cyclohexanone ethylene ketal, cyclohexanone 1,2-propa- nediol ketal, butanone ethylene ketal, butanone 1,2-propanediol ketal, 2-phenyl-1,3-dioxolane, 4-methyl-2-phenyl-1,3-dioxolane, 2-propyl-1,3-dioxolane, 4-methyl-2-propyl-1,3-dioxolane was reported. It has been demonstrated that activated carbon supported tungstosilicic acid is an excellent catalyst. Various factors involved in these reactions were investigated. The optimum conditions found were: molar ratio of aldehyde/ketone to glycol is 1/1.5, mass ratio of the catalyst used to the reactants is 1.0%, and reaction time is 1.0 h. Under these conditions, the yield of 2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane is 61.5%, of 2,4-dimethyl- 2-ethoxycarbonylmethyl-1,3-dioxolane is 69.1%, of cyclohexanone ethylene ketal is 74.6%, of cyclohexanone 1,2-propanediol ketal is 80.1%, of butanone ethylene ketal is 69.5%, of butanone 1,2-propanediol ketal is 78.5%, of 2-phenyl-1,3-dioxolane is 56.7%, of 4-methyl-2-phenyl-1,3-dioxolane is 86.2%, of 2-propyl-1,3-dioxolane is 87.5%, of 4-methyl-2-propyl-1,3-dioxolane is 87.9%.