氢氧化铝/有机改性蒙脱土复合改性沥青性能研究

采用氢氧化铝(ATH)和两种有机改性蒙脱土(OMMT-C、OMMT-F)对沥青进行阻燃抑烟改性,旨在提高隧道沥青路面的阻燃抑烟性能。通过测试三大指标来评价ATH/OMMT复合改性沥青的常规性能,测试极限氧指数(LOI)与烟密度(SDR)来评价其阻燃抑烟性能,利用动态剪切流变(DSR)试验研究其流变性能。基于综合指数法优选出ATH/OMMT复合改性沥青的最佳复掺配比,通过热重(TG)试验分析了ATH/OMMT复合改性沥青的热解燃烧特性并建立了阻燃性能预测模型。研究结果表明,ATH/OMMT复合阻燃剂提高了沥青的稠度与软化点,降低了沥青的低温性能。当ATH掺量为10%(质量分数),OMMT-C掺量为3%(质量分数)时,复合改性沥青的综合性能最优,其极限氧指数大于23%,符合路用阻燃沥青的标准,同时烟密度相对基质沥青降低了33.9%,初始分解温度较基质沥青提高了3~6 ℃,分解残余量提高率最高可达61.3%。ATH/OMMT-C复合阻燃剂通过阻隔热交换通道提高了沥青的阻燃抑烟性能,通过增加沥青的弹性成分提高了沥青的复数模量与车辙因子,以及高温抗变形能力。     

阻燃处理对竹粉增强聚乳酸复合材料阻燃抑烟性能影响

分别采用氢氧化铝(ATH)、聚磷酸铵(APP)及ATH+ APP复合阻燃剂对竹粉增强聚乳酸复合材料进行阻燃抑烟处理,并对处理后的复合材料性能进行测试与表征.结果表明,两种阻燃剂均显著增加了复合材料的成炭率,ATH+ APP产生了协同作用,使复合材料成炭率提高了近4倍,达到了45.3％;复合材料经阻燃处理后其阻燃性能均得到了不同程度的提升.其中,APP对复合材料燃烧过程中热量释放的抑制作用最明显,ATH对复合材料表现出了较强的抑烟效果,而ATH +APP复合阻燃剂产生的协同作用使复合材料具有阻燃和抑烟的双重特性.     

阻燃改性沥青及其混合料性能探析

为了降低沥青在封闭环境中的燃烧风险,本文选用氢氧化铝(ATH)及氢氧化镁(MH)阻燃剂作为主要的阻燃改性剂对基质沥青和SBS改性沥青进行改性,制备了具备阻燃性能的沥青材料,采用氧指数试验全面评价不同类型阻燃改性沥青的阻燃性能,并采用马歇尔试件燃烧试验对其阻燃性能进行验证,在此基础上,采用高温稳定性试验及低温抗裂性试验评价阻燃改性沥青混合料的路用性能。     

ATH/EVMT/ATO复合阻燃剂对HDPE阻燃性能的影响

将高密度聚乙烯(HDPE)作为主要原料,POE-g-MAH为相容剂,氢氧化铝(ATH)、膨胀蛭石(EVMT)和三氧化二锑(ATO)为复合抑烟阻燃剂,通过密炼、粉碎和注塑等工艺制备了抑烟型阻燃HDPE材料.分析了 POE-g-MAH含量、ATH/EVMT配比及(ATH/EVMT)填充量对HDPE材料力学性能和阻燃性能的影...     

ATH和APP对聚乳酸/竹粉复合材料阻燃抑烟性能的影响

利用竹粉和聚乳酸为原料复合制备聚乳酸/竹粉复合材料,分别采用氢氧化铝(ATH)和聚磷酸铵(APP)阻燃剂对聚乳酸/竹粉复合材料进行阻燃抑烟处理并对阻燃处理后的复合材料进行性能测试。结果表明,两种阻燃剂的加入均使复合材料高温下的成炭率提高了约2倍,分别达到了24.7%和25.6%;ATH和APP的加入均有效提高了聚乳酸/竹粉复合材料的阻燃性能;其中,APP对复合材料燃烧过程中热量释放的抑制明显,其热释放速率在燃烧100s以后下降了近2倍,约为150kW/m2,但生烟量大;而ATH对复合材料的抑热效果不及APP,但抑烟效果显著,平均烟释放速率只有约0.02m2/s。     

四溴双酚-A阻燃体系在HIPS／OMMT复合材料中的阻燃性研究

采用熔融插层法分别制备高抗冲苯乙烯／有机蒙脱土（HIPS／OMMT）复合材料和四溴双酚-A／三氧化二锑（TBBPA—Sb2O3）体系阻燃的HIPS／OMMT复合材料,透射电镜研究表明,有机蒙脱土均匀地分散于HIPS基体当中,形成了插层复合结构,锥形量热仪和氧指数仪研究表明：与纯的HIPS相比,HIPS／OMMT复合材料的阻燃性和抑烟性有所提高,但阻燃性的提高幅度较有限：与仅添加OMMT时的HIPS／OMMT复合材料相比,添加相同量OMMT时TBBPA—Sb2O3体系阻燃的HIPS／OMMT复合材料的热释放速率（HRR）和热释放速率峰值（PHRR）均有所降低,氧指数有所增加,且随TBBPA—Sb2O3阻燃剂添加量的增加阻燃性能的提高越明显,但TBBPA—Sb2O3的加入会导致聚合物燃烧过程生烟速率和生烟量的显著增加．因此此类阻燃剂的加入量不宜过高。     

蒙脱土/EPDM纳米复合材料燃烧性能的研究

采用熔融插层法制备了蒙脱土/EPDM纳米复合材料,并研究了燃烧性能。结果表明,EPDM大分子不能与未有机化的钠基蒙脱土(Na+-MMT)插层复合,但能有效插入有机蒙脱土(OMMT)片层之间,形成OMMT/EPDM插层纳米复合材料。Na+-MMT对改善蒙脱土/EPDM纳米复合材料的阻燃和抑烟效果不明显;OMMT/EPDM纳米复合材料的热释放速率、总生烟量及烟密度等参数均明显降低;随OMMT用量的增大,阻燃性和抑烟性变得越来越好,最后趋于稳定。     

复合阻燃剂阻燃硬质聚氨酯泡沫塑料的性能研究

制备了复合阻燃剂阻燃硬质聚氨酯(PUR-R)泡沫塑料,研究了复合阻燃剂甲基膦酸二甲酯(DMMP)、三(2-氯异丙基)磷酸酯(TCPP)、可膨胀型石墨(EG)和氢氧化铝(ATH)对PUR-R泡沫塑料阻燃性能的影响,采用正交试验确定了复合阻燃剂的最佳配比。用极限氧指数(LOI)测定仪、烟密度测定仪和万能试验机测定了阻燃PUR-R泡沫塑料的LOI、烟密度等级和压缩强度,结果表明,当DMMP,TCPP,EG,ATH的质量比为2∶2∶3∶3时,在25份聚醚多元醇中添加12份复合阻燃剂,制备的阻燃PUR-R泡沫塑料的LOI达26.3%,烟密度等级为77.63,压缩强度为0.18 MPa,阻燃PUR-R泡沫塑料具有良好的综合性能。     

阻燃剂表面改性对阻燃沥青性能的影响

为提高阻燃剂与沥青的相容性,对阻燃剂进行表面改性并用于制备阻燃沥青.通过沥青氧指数试验、软化点试验、动态剪切流变试验、延度试验和离析试验评价阻燃剂对沥青阻燃性能、高、低温性能及储存稳定性的影响并确定最佳掺量.借助热重(TG)和扫描电镜(SEM)分析阻燃剂的表面改性机理和阻燃机理.结果表明,阻燃剂可以显著提高沥青的阻燃性能和高温性能,当掺量不超过8%,对沥青的低温性能和储存稳定性影响较小;阻燃剂可以促进沥青成炭,减少沥青燃烧时气体挥发物的逸出;表面改性会提高阻燃剂的分散性和阻燃沥青的热稳定性,改善阻燃沥青的阻燃性能和低温性能.     

隧道沥青路面阻燃抑烟技术及机理研究进展

介绍了沥青燃烧特性及阻燃机理,综述了隧道沥青路面阻燃技术和沥青抑烟技术。从组成成分对比分析了阻燃剂阻燃、组分阻燃、多孔结构阻燃、纳米阻燃及复合协同阻燃等阻燃技术的优势和不足;从改进制备工艺和添加抑烟除味剂等方面介绍了沥青抑烟技术的特点,并归纳了沥青阻燃抑烟性能测试方法,最后分析了隧道沥青路面阻燃抑烟技术面临的问题并展望其前景,为改善隧道沥青路面阻燃抑烟性能提供理论参考。     

乙苯,苯乙烯的生产及合成乙苯,苯乙烯催化剂的研究进展

苯乙烯是重要的石油化工原料。本文介绍了国内外苯乙烯生产的发展概况，合成乙苯，苯乙烯所用的催化剂种类，并就苯乙烯生产及催化剂的发展趋势提出了自己的观点。     

Synthesis and characterization of homopolymers and copolymers of various acrylates and acrylonitrile

Various homopolymers and copolymers of methyl acrylate, ethyl acrylate, butyl acrylate, and acrylonitrile in different feed ratios were synthesized. These were characterized by IR, ¹³C-NMR, DSC, DTA, and TGA. Spectroscopic characterization helped in differentiating copolymers of different mol ratios. Thermal analysis revealed different degradation patterns for homopolymers and copolymers. The temperature and energy changes associated with various phase transitions were dependent on the chemical composition of homo- and copolymers, as expected. © 1993 John Wiley & Sons, Inc.     

生物质气化及生物质与煤共气化技术的研发与应用

总结了生物质原料的特点及生物质单独气化的缺点;介绍了国内外生物质气化技术及生物质与煤共气化技术的研发与应用现状;分析了在此领域国内外的发展趋势与前景;概括了开展生物质与煤共气化技术研发的意义。     

责任和责任心的涵义与结构

责任是人应主动承担的角色义务和对其因过失所造成后果应承担的责罚.有两层涵义:一是义务;二是后果.责任心是个体自觉做好分内事务和履行道德义务的心理倾向,是个性心理品质成分中自我特征维度上的重要内容.责任心具有两个方面的涵义:一是角色分内职责;二是角色道德义务.责任心是一种通过责任认知、责任个性和责任适应的动态形式表现出来的静态品质,责任心是责任心过程结构与责任心关系结构相互制约、相互影响的统一体.     

二甲基二烯丙基氯化铵和丙烯酰胺的合成及应用

用复合引发体系(过硫酸盐-偶氮类引发剂)和脂肪胺类氧化还原体系引发,在实验室获得了单体转化率≥98%,特性粘数高于13.6 dL/g的阳离子共聚物PDA,探讨了控制聚合物分子量的影响因素.     

Comparison of the Adhesion and Cohesion of Triblock and Random Copolymers of Styrene and Butadiene

A substantially greater detachment energy is required to strip a polyethylene tereph-thalate (Mylar) film from a styrene-butadiene-styrene (SBS) triblock copolymer compared to that for peeling from a random styrene-butadiene (SBR) copolymer. This is true even though the intrinsic interaction between the Mylar and each elastomer is expected to be similar because of their virtually identical chemical composition. It is proposed that this difference in peel strength (between the SBS and SBR) is a consequence of the much higher dissipative capacity of the former elastomer. Another manifestation of this is the higher cohesive tear strength of the SBS compared to the SBR. Extents of energy dissipation within each elastomer during detachment of the Mylar adherend are consistent with the hypothesis that the average maximum stress experience before detachment is some similar fraction of each elastomer's tensile strength.     

Kinetics and Mechanism of Oxidation of Mono- and Polyacetals

Abstract

Kinetics and mechanisms of oxidation of 6 acetals by molecular oxygen and ozone in liquid phase have been studied. Reaction with molecular oxygen (70°C, 15–16 hr) leads to the formation monoethers of the corresponding glycols with 68–90% selectivity. Salts of metals and complexes with crown-ethers have increased the reaction rate significally. Ozone have reacted with acetals with formation similar products. The mechanisms of intermediate stages have been proposed.     

钾盐资源及钾肥供需情况分析及预测

阐述了国内外钾盐资源及钾肥生产现状,对国内外钾盐的供需形势进行了分析及预测,从资源、原材料、国际市场三方面提出了解决我国钾盐短缺的措施。     

Electronic structures and reactivities of monometallic and bimetallic clusters of Au and Cu

The variation of the Au 4f binding energy of Au clusters with the cluster size has been established by measuring the binding energies of clusters whose size distributions were independently determined by HREM and STM. The binding energy increases significantly when the cluster size is less than 2 nm. Au-Cu bimetallic clusters of the composition Cu₃Au have been deposited for the first time on carbon substrates. The shifts in the core level binding energies of the bimetallic clusters show the effect of alloying in the case of large clusters, but show effects of both alloying and cluster size in the case of the small clusters. The interaction of CO with Cu₃Au clusters is stronger than with a bulk Cu metal. The interaction of CO with small Cu clusters also seems to be stronger than with bulk Cu or with large Cu clusters.     

Wetting properties of homopolymers and copolymers of pentafluorostyrene and methylacrylate and homopolymer blends

Polypentafluorostyrene (PPFS), polymethylacrylate (PMA), and poly(pentafluorostyrene-co-methylacrylate), poly(PFS-co-MA) were prepared and the wetting characteristics of polymer blends of PPFS and PMA were compared with that of poly(PFS-co-MA) via contact angle measurements. The critical surface tension of polypentafluorostyrene was found to be 22.6 dyne/cm, which is comparable to the value reported for polytrifluoroethylene (22 dyne/cm). The critical surface tension of poly(PFS-co-MA) is not linearly related to its composition. The polymer blends of PPFS and PMA exhibit significant surface enrichment of the fluoropolymer. The harmonic-mean method¹ was employed to determine surface tensions of these polymers and many known polymers. It is found that the method produces useful surface tension data provided the contact angle values are derived from testing liquids of dissimilar polarity.