可膨胀石墨在膨胀型钢结构防火涂料中的应用

为了改善钢结构防火涂料膨胀炭质层蓬松易脱落和易开裂的缺点,将可膨胀石墨(EG)添加到防火涂料中,通过耐火实验来研究EG对炭质层形貌和钢结构耐火极限的影响。结果表明,EG膨胀后成“蠕虫”状穿插于膨胀炭质层中,起到增强作用,使炭质层结构更致密。热分析结果表明,w(EG) =6 7%时,防火涂料在600℃时的热失重减少了7%;w(EG) =0 5%时,钢结构耐火极限延长了10min。     

MoO3与可膨胀石墨改性聚磷酸铵/季戊四醇/三聚氰胺防火涂料研究

采用MoO3、可膨胀石墨(EG)和MoO3/EG对APP/PER/MEL膨胀防火涂料进行改性,制备成改性涂料,运用隔热性能分析和热重分析(TGA)测试改性涂料的耐火极限和残碳率.结合扫描电镜分析结果,探讨MoO.EG和MoO3/EG对涂料耐火性能提高的途径分别为MoO3通过与APP/PER/MEL涂料体系作用提高了涂料残碳率;EG通过自身膨胀产生"蠕虫"结构显著改善了碳层结构;而MoO3/EG则通过MoO3和EG各自的作用,产生了明显的协同增效效果.     

新型阻燃体系对木塑防火涂层阻燃性能的影响

采用隔热性能试验、热失重分析(TG)、傅里叶红外光谱分析(FTIR)以及显微分析等方法,研究了两种改性材料膨胀石墨(EG)和云母对膨胀防火涂层防火性能和热降解行为的影响。结果表明:EG与云母加入后不会改变涂层的基本阻燃进程,且会提高膨胀炭质层的热稳定性,涂层的阻燃效果显著改善。     

海泡石和EG对水性膨胀型钢结构防火涂料的影响

采用可膨胀性石墨(EG)和海泡石对传统的APP/PER/MEL膨胀型防火涂料体系进行改性,制备了一种新型水性超薄膨胀型防火涂料,并采用防火性能测试装置、热重分析(TGA)、差热重量分析(DTG)及X射线衍射(XRD)等方法对该防火涂料的耐火性能、热降解过程、炭化层结构进行了研究。热分析结果表明,海泡石与EG复合使用,将充分发挥它们的协同作用:EG在较低温度区域能够延缓炭化层的形成,而海泡石则能够在高温区域阻止炭化层氧化分解,并提高成炭率从而达到阻燃的目的。XRD结果显示,复合使用EG和海泡石能够促进炭化层中TiP2O7的形成,在高温阶段保护炭化层不被氧化。当防火涂料中添加质量分数3%海泡石和质量分数2%EG,涂层厚度为1.0 mm时,钢材的耐火时间达到72 min。     

钼酸铵与可膨胀石墨改性超薄型钢结构防火涂料的研究

采用钼酸铵(AM)、可膨胀石墨(EG)和AM/EG对三聚氰胺聚磷酸盐(MPP)/三聚氰胺(MEL)/季戊四醇(PER)超薄型防火涂料进行改性,制备改性涂料.耐火性能测试、TGA分析表明,与EG改性相比,AM、EG协同改性延长了耐燃时间,提高了残炭量.采用Freeman方法计算了防火涂料的热降解活化能,AM/EG改性较EG改性的防火涂料在200～330℃、330～500℃阶段的活化能分别提高了59.72 kJ/mol和67.71 kJ/mol,AM/EG改性防火涂料防火性能好.     

海泡石和可膨胀性石墨对水性超薄膨胀型钢结构防火涂料阻燃性能的影响

采用可膨胀性石墨（EG）和海泡石对传统的APP/PER/MEL膨胀型防火涂料体系进行改性,制备了一种新型水性超薄膨胀型防火涂料,并采用防火性能测试装置、热重分析（TGA）、差热重量分析（DTG）及X射线衍射（XRD）等方法对该防火涂料的耐火性能、热降解过程、碳化层结构进行了研究。热分析结果表明,海泡石与EG复合使用,将充分发挥它们的协同作用：EG在较低温度区域能够延缓碳化层的形成,而海泡石则能够在高温区域阻止碳化层氧化分解,并提高成炭率从而达到阻燃的目的。XRD结果显示,复合使用EG和海泡石能够促进碳化层中TiP2O7的形成,在高温阶段保护碳化层不被氧化。当防火涂料中添加3wt%海泡石和2wt%EG,涂层厚度为1mm时,钢材的耐火时间达到72min。     

室内水性膨胀型防火涂料的性能测试

用壁挂式酒精喷灯模拟火灾现场,对一种室内水性膨胀型钢结构防火涂料的耐火极限和膨胀倍数进行测试。采用热重/差热(TG/DTG)对涂料的热稳定性进行表征,用红外光谱(IR)和X-射线衍射(XRD)分析燃烧后炭层结构,用数码相机和SEM观察炭层的形貌。结果表明,该涂料的耐火极限为160 min,膨胀倍数为12.2,最大失重温度为328℃,涂料受热分解后生成含有P—C—O、—CH_2—、■和—OH结构的炭化物,炭层中含有TiO_2与TiP_2O_7,且炭层呈现"蜂窝状"多孔结构。该防火涂料的性能符合GB 14907—2018《钢结构防火涂料》国家标准,性能优异,在室内钢结构的防火保护中可以广泛使用。     

可膨胀石墨在水性饰面防火涂料中的应用

以可膨胀石墨(EG)为物理膨胀体系,制备了膨胀型水性饰面防火涂料,采用小室法、锥形量热仪(CONE)、扫描电镜(SEM)等手段分析了可膨胀石墨及其与阻燃协效剂复配对饰面膨胀型防火涂料性能的影响。研究发现,EG的加入改善了膨胀炭质层的结构,大大提高了涂料的防火性能。选用3.5g、80目的EG,所得涂料的防火性能最佳,耐火时间达33min。可膨胀石墨与阻燃协效剂复配能够进一步降低涂料燃烧的烟气释放。当EG与二氧化锡按质量比为1∶1复配,所得涂层的生烟速率峰值与仅含EG的涂层相比下降78.4%,抑烟性能最好。     

水性饰面型防火涂料的制备及其耐火性能研究

以可膨胀石墨(EG)和绢云母为新的阻燃材料,三聚氰胺(MEL)、聚磷酸铵(APP)、季戊四醇(PER)为膨胀阻燃体系,水性乳液为基体制备水性饰面型防火涂料;采用自制高温电炉装置,研究EG与绢云母配比、膨胀阻燃体系、基体拼合对水性饰面防火涂料性能的影响.结果表明,可膨胀石墨和绢云母的质量比为5∶3,APP/MEL/PER的质量比为4∶3∶3,氯偏乳液与纯丙AC261P乳液质量比为22∶3时,制备的防火涂料涂层受热膨胀效果显著,形成了“窝状”构的膨胀炭质层,炭质层孔洞均匀致密,与基材粘附性好、强度高,耐火性能最好,耐火时间高达22min.     

水性超薄膨胀型钢结构防火涂料的制备

以有机硅改性的丙烯酸酯乳液为基料,多聚磷酸铵(APP)、季戊四醇(PER)、三聚氰胺(MEL)为膨胀阻燃体系,制备水性超薄膨胀型钢结构防火涂料;采用硼酸和可膨胀石墨(EG)改性防火涂料。研究表明,同时用w(硼酸)=4%,w(EG)=5%改性防火涂料,涂层的耐火极限达到93 min,热失质量分析(TGA)测试表明w(硼酸)=4%,w(EG)=5%共同改性的防火涂料在700℃时最终残炭量是44%。扫描电镜(SEM)分析结果表明硼酸/EG改性的残炭层形成了致密的"蜂窝"状结构。     

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。     

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.     

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。     

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.     

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.     

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.     

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.