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生物炭纤维的形成机制(II)—PAN基热氧稳定化纤维的炭化与活化研究 被引量:10
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作者 刘杰 何振坤 +1 位作者 王绍堂 赵兴利 《新型炭材料》 SCIE EI CAS CSCD 2001年第3期42-47,共6页
以聚丙烯腈共聚纤维制取了生物炭纤维 (BCF)。考察了炭化活化过程中活化剂、热处理参数对BCF结构、性能的作用以及纤维序态结构、化学结构与生物炭纤维吸附特性、力学性能、电性能间的内在关联。研究结果表明 :1)醋酸可作为活化剂 ,用... 以聚丙烯腈共聚纤维制取了生物炭纤维 (BCF)。考察了炭化活化过程中活化剂、热处理参数对BCF结构、性能的作用以及纤维序态结构、化学结构与生物炭纤维吸附特性、力学性能、电性能间的内在关联。研究结果表明 :1)醋酸可作为活化剂 ,用于制备综合性能优异的BCF。 2 )BCF收率、力学性能、吸附特性、电性能等综合性能的变化与热处理温度、时间、活化剂的变化密切相关。 3)BCF的化学组成 ,直径、取向度、微晶尺寸等形态、序态结构参数与BCF力学性能、吸附特性等使用性能的优劣具有密切关联 ,且均在 5 0 0℃和活化前后出现不同的变化速率。 展开更多
关键词 BCF 生物炭纤维 聚丙烯腈 炭化 结构 性能 形成机制 热氧稳定化纤维
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BCF的热氧稳定化研究 被引量:8
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作者 刘杰 梁节英 《北京化工大学学报(自然科学版)》 CAS CSCD 2002年第3期24-27,共4页
采用连续实验方法,借助X射线衍射、红外光谱、元素分析、力学测试等技术,系统地研究了热氧稳定化过程中聚丙烯腈纤维序态结构、化学结构与生物碳纤维吸附特性、力学性能的内在关联与作用。研究结果表明:聚丙烯腈基热氧稳定化纤维晶区尺... 采用连续实验方法,借助X射线衍射、红外光谱、元素分析、力学测试等技术,系统地研究了热氧稳定化过程中聚丙烯腈纤维序态结构、化学结构与生物碳纤维吸附特性、力学性能的内在关联与作用。研究结果表明:聚丙烯腈基热氧稳定化纤维晶区尺寸、取向指数等结构参数与BCF比表面积、吸附特性及力学性能的优劣具有直接内在联系。在热氧稳定化过程中增加聚丙烯腈纤维热氧稳定化结构转化有益于改善生物碳纤维吸附特性,且与生物碳纤维力学性能的变化密切相关。 展开更多
关键词 生物碳纤维 聚丙烯腈 炭化 结构 性能 热氧稳定化
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热氧稳定化过程中聚丙烯腈纤维序态结构的变化 被引量:7
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作者 刘杰 阳武 《材料研究学报》 EI CAS CSCD 北大核心 2007年第5期487-490,共4页
研究了聚丙烯腈(PAN)共聚纤维在连续热氧稳定化过程中序态结构的变化,结果表明:X射线衍射极图所提供的0°-360°全角扫描信息,可表征纤维内部晶面法向分子链的分布密度,描述分子链取向结构的变化程度;可较全面、动态和直观地解... 研究了聚丙烯腈(PAN)共聚纤维在连续热氧稳定化过程中序态结构的变化,结果表明:X射线衍射极图所提供的0°-360°全角扫描信息,可表征纤维内部晶面法向分子链的分布密度,描述分子链取向结构的变化程度;可较全面、动态和直观地解析聚丙烯腈大分子链在热氧稳定化过程中经历的由初期取向结构改善到中、后期大分子链解取向的全过程.在较低的热氧稳定化温度下,PAN大分子链无序区先发生化学反应,有序度变化不大;当热处理提供的能量超过有序区环化和改变分子构象所需要的能量时,有序区发生剧烈的热化学反应,有序度急剧下降. 展开更多
关键词 有机高分子材料 聚丙烯腈(PAN) 炭纤维热氧稳定化 序态结构
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250℃下时间效应对PAN纤维热氧稳定化反应的影响及关联
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作者 刘杰 张月义 +1 位作者 马兆昆 梁节英 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2012年第6期80-84,共5页
借用傅里叶变换红外光谱(FT-IR)、元素分析(EA)、X射线衍射(XRD)和示差扫描量热分析(DSC)等手段,对比研究了热氧稳定化过程中250℃下时间效应与两种聚丙烯腈(PAN)共聚纤维及其炭纤维结构和性能之间的关联。研究结果表明,PAN纤维在250℃... 借用傅里叶变换红外光谱(FT-IR)、元素分析(EA)、X射线衍射(XRD)和示差扫描量热分析(DSC)等手段,对比研究了热氧稳定化过程中250℃下时间效应与两种聚丙烯腈(PAN)共聚纤维及其炭纤维结构和性能之间的关联。研究结果表明,PAN纤维在250℃温区内停留超过9min时,最终热氧稳定化纤维的环化度(RCI)、体密度和芳构化指数(AI)的增加速率开始变小;炭纤维的孔含量(Vp)值与内部微晶的d002值开始增大,微晶排列的规整程度变差,缺陷增多,拉伸强度开始降低。 展开更多
关键词 聚丙烯腈 热氧稳定化 炭纤维 时间 孔含量
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改性热氧稳定化纤维碳化行为的特点
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作者 崔宁 《纺织科学研究》 2007年第2期21-25,51,共6页
以经过化学改性和热氧稳定化处理的聚丙烯腈(PAN)基预氧化纤维为原料,借助X-射线衍射、热重分析、力学性能、元素分析等手段,研究了改性热氧稳定化纤维碳化行为的特点。同时,通过对比改性PAN原丝与未改性PAN原丝的碳化过程,讨论... 以经过化学改性和热氧稳定化处理的聚丙烯腈(PAN)基预氧化纤维为原料,借助X-射线衍射、热重分析、力学性能、元素分析等手段,研究了改性热氧稳定化纤维碳化行为的特点。同时,通过对比改性PAN原丝与未改性PAN原丝的碳化过程,讨论了二者物理、化学性质和力学性能的区别。实验结果表明,对原丝进行化学改性能够影响纤维的碳化行为。改善碳纤维的结构。并最终提高碳纤维的力学性能。 展开更多
关键词 聚丙烯腈基预化纤维 改性热氧稳定化 碳化行为
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PAN基碳纤维形成过程中热氧稳定化气氛对纤维径向结构演变的关联性研究 被引量:3
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作者 刘杰 欧阳新峰 +1 位作者 连峰 梁节英 《高分子学报》 SCIE CAS CSCD 北大核心 2012年第11期1326-1334,共9页
采用红外光谱、X射线能谱、激光显微共焦拉曼光谱、X射线衍射光谱和电子自旋共振等多种表征手段,定量探讨了热氧稳定化气氛中氧气浓度与聚丙烯腈纤维的径向结构转变以及与碳纤维结构和性能的关联.结果表明,随着氧气浓度的增大,氧气自皮... 采用红外光谱、X射线能谱、激光显微共焦拉曼光谱、X射线衍射光谱和电子自旋共振等多种表征手段,定量探讨了热氧稳定化气氛中氧气浓度与聚丙烯腈纤维的径向结构转变以及与碳纤维结构和性能的关联.结果表明,随着氧气浓度的增大,氧气自皮层逐渐扩散到纤维内部,热氧稳定化纤维的径向结构趋于均质化.当热氧稳定化过程氧体积浓度(Vo)由20.38%增加到21.15%时,热氧稳定化纤维的皮芯结构逐渐减小,环化程度增幅显著,该过程对碳纤维皮部类石墨结构的形成具有促进作用,所得碳纤维的孔隙率减小,拉伸强度增大.当Vo大于21.34%时,热氧稳定化纤维的皮芯结构基本消失,但氧化程度过高且环化程度增幅缓慢,抑制了碳纤维皮部类石墨结构的形成,所得碳纤维的孔隙率增大,拉伸强度降低.控制Vo为21.15%~21.34%时,热氧稳定化纤维的环化和径向化学结构的均质化程度均得以提高,所得碳纤维在保持皮部较高石墨程度的同时促进了芯部类石墨结构的形成,此时拉伸强度最高,比在常规空气气氛条件下制备的碳纤维提高了12.22%. 展开更多
关键词 聚丙烯腈 气氛 径向结构 热氧稳定化 碳纤维
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热氧稳定化过程温度效应对PAN纤维径向氧元素扩散速率的作用 被引量:3
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作者 刘杰 王新文 +1 位作者 马兆昆 梁节英 《复合材料学报》 EI CAS CSCD 北大核心 2012年第2期26-34,共9页
在梯度升温和恒温两种模式下,对聚丙烯腈(PAN)纤维进行了热氧稳定化处理,借助FTIR、核磁共振碳谱(13 C-NMR)、元素分析(EA)、DSC、X-射线能谱(EDS)、密度等多种表征手段系统研究了不同温度下热氧稳定化纤维皮-芯结构的形成机制和氧元素... 在梯度升温和恒温两种模式下,对聚丙烯腈(PAN)纤维进行了热氧稳定化处理,借助FTIR、核磁共振碳谱(13 C-NMR)、元素分析(EA)、DSC、X-射线能谱(EDS)、密度等多种表征手段系统研究了不同温度下热氧稳定化纤维皮-芯结构的形成机制和氧元素的扩散速率。研究结果表明:氧化反应速率小于氧的扩散速率时,PAN纤维横截面外层与芯部差别较大,将出现皮-芯形貌结构特征;热氧稳定化纤维皮-芯结构的产生不但与温度有关,而且与升温模式密切相关;EDS表征方法可以有效地量化不同温度下,热氧稳定化纤维径向氧元素的扩散速率,同时可直观显示出氧在纤维截面不同区域的结合速率。 展开更多
关键词 聚丙烯腈纤维 温度 热氧稳定化 元素 皮-芯结构
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Thermally robust silica-enclosed Au_(25) nanocluster and its catalysis 被引量:4
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作者 陈海军 刘超 +3 位作者 王敏 张超锋 李杲 王峰 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第10期1787-1793,共7页
Well-defined gold nanoclusters with average size less than 2 nm have emerged as a new and novel catalyst. The gold nanocluster loaded on the oxide surface usually aggregates to larger particles at high temperature (... Well-defined gold nanoclusters with average size less than 2 nm have emerged as a new and novel catalyst. The gold nanocluster loaded on the oxide surface usually aggregates to larger particles at high temperature (〉 300℃), which is caused by the removal of the surface ligands. We herein pre-sent a novel method to prepare Au25cluster catalyst (-1.3 nm) with high thermal stability (up to 400℃). Au25@Si02 is synthesized via a co-hydrolyzing reaction of Au2s[SC3H6Si(OCH3)3118 and tet-raethyl orthosilicate, and then it is treated at different temperature (e.g., 200, 300, 400℃) in air to remove the organic ligands. Au25@SiO2 is well characterized by transmission electron microscopy, ultraviolet-visible spectroscopy and diffuse reflectance UV-vis spectroscopy. Further, the Au2s@SiO2 catalysts are investigated in the hydrogenation ofp-nitrophenol into p-aminophenol. 展开更多
关键词 Gold nanoclusterAu2sThermal stabilitySilicaHydrogenation
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Catalytic oxidation of diesel soot particulates over Ag/LaCoO_3 perovskite oxides in air and NO_x 被引量:6
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作者 樊琪 张帅 +4 位作者 孙礼英 董雪 张澜萃 单文娟 朱再明 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第3期428-435,共8页
Ag/LaCoO3 perovskite catalysts for soot combustion were prepared by the impregnation method.The structure and physicochemical properties of the catalysts were characterized using X-ray diffraction,N2 adsorption-desorp... Ag/LaCoO3 perovskite catalysts for soot combustion were prepared by the impregnation method.The structure and physicochemical properties of the catalysts were characterized using X-ray diffraction,N2 adsorption-desorption,H2 temperature-programmed reduction,soot temperatureprogrammed reduction,and X-ray photoelectron spectroscopy.The catalytic activity of the catalysts for soot oxidation was tested by temperature-programmed oxidation in air and in a NOx atmosphere.Metallic Ag particles were the main Ag species.Part of the Ag migrated from the surface to the lattice of the LaCoO3 perovskite,to form La(1-x)AgxCoO3.This increased the amount of oxygen vacancies in the perovskite structure during thermal treatment.Compared with unmodified LaCoO3,the maximum soot oxidation rate temperature(Tp) decreased by 50-70 ℃ in air when LaCoO3 was partially modified by Ag,depending on the thermal treatment temperature.The Tp of the Ag/LaCoO3catalyst calcined at 400℃ in a NOx atmosphere decreased to about 140℃,compared with that of LaCoO3.Ag particles and oxygen vacancies in the catalysts contributed to their high catalytic activity for soot oxidation.The stable catalytic activity of the Ag/LaCoO3 catalyst calcined at 700℃ in a NOx atmosphere was related to its stable structure. 展开更多
关键词 Soot combustion NOx SILVER PEROVSKITE Thermal stability
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Synthesis and characterization of colored layered double hydroxides for thermal stabilizer 被引量:1
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作者 刘循军 张玉超 +1 位作者 王娟 雷立旭 《Journal of Southeast University(English Edition)》 EI CAS 2015年第4期566-571,共6页
Colored layered double hydroxides (LDHs) can be synthesized by introducing colored cations such as Fe^3+ and Cr^3 +, which call be used as thermal stabilizers for polyvinyl chloride (PVC). The yellowish Mg/Fe an... Colored layered double hydroxides (LDHs) can be synthesized by introducing colored cations such as Fe^3+ and Cr^3 +, which call be used as thermal stabilizers for polyvinyl chloride (PVC). The yellowish Mg/Fe and bluish Mg/Cr LDHs are prepared by the co-precipitation method. The results show that the MgsCr_ CO3 and Mg3Fe_ CO3 colored layered double hydroxides can stabilize PVC for more than 30 min under the thermal aging temperature of 180 ℃. The preparation can use cheap Mg(OH) 2 instead of MgCl2, which produces a much smaller amount of the by-product NH4Cl. It is known that NH4Cl is a cheap fertilizer that is difficult to sell; therefore, the preparation is much greener and more economic than the one using magnesium salt. 展开更多
关键词 colored layered double hydroxides magnesiumhydroxide ferric chloride chromic chloride thermalstabilizer polyvinyl chloride
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Investigation of low-temperature hydrothermal stability of Cu-SAPO-34 for selective catalytic reduction of NO_x with NH_3 被引量:10
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作者 Xiao Xiang Pengfei Wu +5 位作者 Yi Cao Lei Cao Quanyi Wang Shutao Xu Peng Tian Zhongmin Liu 《Chinese Journal of Catalysis》 EI CSCD 北大核心 2017年第5期918-927,共10页
The low‐temperature hydrothermal stabilities of Cu‐SAPO‐34samples with various Si contents and Cu loadings were systematically investigated.The NH3oxidation activities and NH3‐selective catalytic reduction(SCR)act... The low‐temperature hydrothermal stabilities of Cu‐SAPO‐34samples with various Si contents and Cu loadings were systematically investigated.The NH3oxidation activities and NH3‐selective catalytic reduction(SCR)activities(mainly the low‐temperature activities)of all the Cu‐SAPO‐34catalysts declined after low‐temperature steam treatment(LTST).These results show that the texture and acid density of Cu‐SAPO‐34can be better preserved by increasing the Cu loading,although the hydrolysis of Si-O-Al bonds is inevitable.The stability of Cu ions and the stability of the SAPO framework were positively correlated at relatively low Cu loadings.However,a high Cu loading(e.g.,3.67wt%)resulted in a significant decrease in the number of isolated Cu ions.Aggregation of CuO particles also occurred during the LTST,which accounts for the decreasing NH3oxidation activities of the catalysts.Among the catalysts,Cu‐SAPO‐34with a high Si content and medium Cu content(1.37wt%)showed the lowest decrease in NH3‐SCR because its Cu2+content was well retained and its acid density was well preserved. 展开更多
关键词 Cu‐SAPO‐34 Low temperature hydrothermal stability Nitrogen oxides Selective catalytic reduction Ammonia oxidation
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Modification of nano-TiO_2 by Al_2O_3 in-situ coating 被引量:1
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作者 柴立元 苏维丰 +5 位作者 彭兵 王云燕 韦顺文 苑春 于延芬 郝赟 《Journal of Central South University of Technology》 EI 2006年第1期17-21,共5页
A novel technology of in-situ coating Al2O3 on the surface of H4TiO4 was developed to prevent the aggregation of nano-TiO2 powders and improve the dispersibility and thermal stability in the way of forming a uniform c... A novel technology of in-situ coating Al2O3 on the surface of H4TiO4 was developed to prevent the aggregation of nano-TiO2 powders and improve the dispersibility and thermal stability in the way of forming a uniform coating layer. The heterogeneous nucleation was conducted to prepare the precursor of nano-TiO2 and then Al2O3 was coated on the surface of precursor. The effects of Al2O3 in-situ coating on the properties of nano-TiO2 were investigated. The results show that H4 TiO4 can be dispersed well under alkaline condition (pH 8. 5) and the heterogeneous nucleation can be controlled easily. The optimized uniform coating layer is obtained by adding 5 % (mass fraction ) and 10% of Al2O3 and the aggregation of nano-TiO2 powders is effectively inhibited and the dispersibility is obviously improved. The crystal sizes of TiO2 powders are 12.3, 11.4 and 8. 7 nm after coating 0, 5% and 10% of Al2O3 respectively. Al2O3 on the surface of particulates in amorphous phase could increase the thermal stability of nano-partieles after calcined at 550℃. 展开更多
关键词 in-situ coating NANO-TIO2 AGGREGATION DISPERSIBILITY thermal stability
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Highly photoreactive TiO_2 hollow microspheres with super thermal stability for acetone oxidation 被引量:3
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作者 Li Liang Kaining Li +2 位作者 Kangle Lv Wingkei Ho Youyu Duan 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第12期2085-2093,共9页
TiO2hollow microspheres(TiO2‐HMSs)have attracted much attention because of their high photoreactivity,low density,and good permeability.However,anatase TiO2‐HMSs have poor thermal stability.In this study,surface‐fl... TiO2hollow microspheres(TiO2‐HMSs)have attracted much attention because of their high photoreactivity,low density,and good permeability.However,anatase TiO2‐HMSs have poor thermal stability.In this study,surface‐fluorinated TiO2‐HMSs were assembled from hollow nanoparticles by the hydrothermal reaction of the mixed Ti(SO4)2–NH4HF–H2O2solution at180°C.The effect of the calcination temperature on the structure and photoreactivity of the TiO2‐HMSs was systematically investigated,which was evaluated by photocatalytic oxidation of acetone in air under ultraviolet irradiation.We found that after calcination at300°C,the photoreactivity of the TiO2‐HMSs decreases from1.39×10?3min?1(TiO2‐HMS precursor)to0.82×10?3min?1because of removal of surface‐adsorbed fluoride ions.With increasing calcination temperature from300to900°C,the building blocks of the TiO2‐HMSs evolve from truncated bipyramidal shaped hollow nanoparticles to round solid nanoparticles,and the photoreactivity of the TiO2‐HMSs steady increases from0.82×10?3to2.09×10?3min?1because of enhanced crystallization.Further increasing the calcination temperature to1000and1100°C results in a decrease of the photoreactivity,which is ascribed to a sharp decrease of the Brunauer–Emmett–Teller surface area and the beginning of the anatase–rutile phase transformation at1100°C.The effect of surface‐adsorbed fluoride ions on the thermal stability of the TiO2‐HMSs is also discussed. 展开更多
关键词 TiO2 hollow microsphere Photocatalytic oxidation ACETONE FLUORINE Thermal stability
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Structure,mechanical and thermal properties of Y-doped CrAlN coatings 被引量:3
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作者 Jin-lian TIAN Chun HU +2 位作者 Li CHEN Yu-min LOU Ning-ning ZHAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第9期2740-2749,共10页
CrAlYN coatings with different Y contents(0,5 and 12 at.%)were deposited by cathodic arc evaporation to investigate the influence of Y-addition on the structure,mechanical and thermal properties of CrAlN coatings by u... CrAlYN coatings with different Y contents(0,5 and 12 at.%)were deposited by cathodic arc evaporation to investigate the influence of Y-addition on the structure,mechanical and thermal properties of CrAlN coatings by using X-ray diffraction,scanning electron microscopy,differential scanning calorimetry,thermal gravimetric analysis and nanoindentation.The structural transformation of single phase cubic Cr_(0.42)Al_(0.58)N and Cr_(0.39)Al_(0.56)Y_(0.05)N coatings to cubic−wurtzite mixed Cr_(0.32)Al_(0.56)Y_(0.12)N coating leads to a drop in hardness from(30.2±0.7)GPa of Cr_(0.42)Al_(0.58)N and(32.0±1.0)GPa of Cr_(0.39)Al_(0.56)Y_(0.05)N to(25.2±0.7)GPa of Cr_(0.32)Al_(0.56)Y_(0.12)N.The incorporation of 5 at.%Y retards the thermal decomposition of CrAlN,verified by the postponed precipitation of w-AlN and N-loss upon annealing.Correspondingly,Cr_(0.39)Al_(0.56)Y_(0.05)N coating consistently exhibits the highest hardness value during thermal annealing.Nevertheless,alloying with Y exerts an adverse effect on the oxidation resistance of CrAlN. 展开更多
关键词 CrAlYN coatings cathodic arc evaporation structural evolution HARDNESS thermal stability oxidation resistance
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Thermal stability and oil absorption of aluminum hydroxide treated by dry modification with phosphoric acid 被引量:3
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作者 周向阳 李昌林 +3 位作者 霍登伟 李劼 伍上元 刘业翔 《Journal of Central South University of Technology》 EI 2007年第6期779-782,共4页
The dry modification of aluminum hydroxide powders with phosphoric acid and the effects of modification of technological conditions on thermal stability, morphology and oil absorption of aluminum hydroxide powders wer... The dry modification of aluminum hydroxide powders with phosphoric acid and the effects of modification of technological conditions on thermal stability, morphology and oil absorption of aluminum hydroxide powders were investigated. The results show that the increase of mass ratio of phosphoric acid to aluminum hydroxide, the decrease of mass concentration of phosphoric acid and prolongation of mixing time are favorable to the improvement of thermal stability of aluminum hydroxide; when the mass ratio of phosphoric acid to aluminum hydroxide is 5:100, the mass concentration of phosphoric acid is 200 g/L and the mixing time is 10 min, the initial temperature of loss of crystal water in aluminum hydroxide rises from about 192.10 to 208.66 ℃, but the dry modification results in the appearance of agglomeration and macro-aggregate in the modified powders, and the oil absorption of modified powders becomes higher than that of original aluminum hydroxide. 展开更多
关键词 aluminum hydroxide phosphoric acid thermal stability oil absorption dry modification
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Thermal properties of glass-ceramic bonded thermal barrier coating system 被引量:1
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作者 S.GHOSH 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第2期457-464,共8页
The thermal properties of a thermal barrier coating (TBC) system comprised of BaO-MgO-SiO_2 based glass-ceramic bond coating, 8% (mass fraction) yttria stabilized zirconia (8YSZ) top coating and nimonic alloy su... The thermal properties of a thermal barrier coating (TBC) system comprised of BaO-MgO-SiO_2 based glass-ceramic bond coating, 8% (mass fraction) yttria stabilized zirconia (8YSZ) top coating and nimonic alloy substrate were evaluated. The thermal diffusivity and thermal conductivity of the TBC coated substrate were lower than those of bare substrate and glass-ceramic coated substrate under identical conditions. The specific heat capacity, thermal diffusivity and thermal conductivity of the TBC coated substrate increase with the increase of the temperature. Further, it is observed that the thermal conductivity of the TBC system decreases with the increase in the top coating thickness. 展开更多
关键词 vglass-ceramic coating thermal barrier coating thermal properties yttria stabilized zirconia
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Diester Derivatives from Chemically Modified Waste Cooking Oil as Substitute for Petroleum Based Lubricating Oils 被引量:1
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作者 Xiang Shuo Chen Ligong +3 位作者 Xu Lan Li Liang Yang Xin Zhu Liye 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2015年第2期76-83,共8页
In order to provide a new way for waste cooking oil(WCO) resource utilization, several diester derivatives were obtained from WCO through a three-step chemical modifications, viz.: transesterification, epoxidation and... In order to provide a new way for waste cooking oil(WCO) resource utilization, several diester derivatives were obtained from WCO through a three-step chemical modifications, viz.: transesterification, epoxidation and oxirane ring opening with carboxylic acids. The effects of the chain length of side chain groups on the viscosity, acid value, low temperature fluidity, thermo-oxidative stability, tribological properties and surface tension of diester derivatives were investigated. The results showed that increasing the chain length of side chain groups had a positive influence on the viscosity, viscosity index, acid value, pour point, friction coefficient and wear scar diameter along with a negative influence on the oxidation onset temperature, volatile loss, insoluble deposit, maximum non-seizure load and surface tension. These diester derivatives exhibited improved physicochemical and tribological properties that make themselves promising environmentally friendly biolubricant basestocks. 展开更多
关键词 waste cooking oil diester derivative lubricating oil physicochemical property tribological property
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Synthesis and application of antimony pent(isooctyl thioglycollate) 被引量:1
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作者 刘又年 李红兵 +1 位作者 舒万艮 陈启元 《Journal of Central South University of Technology》 2005年第1期64-67,共4页
A new type of thermal stabilizer, antimony pent(isooctyl thioglycollate)(Sb(SCH2COOC8H17)5), was synthesized by using antimony trioxide, isooctanol and thioglycolic acid in 2 steps. Firstly, antimony trioxide was ox... A new type of thermal stabilizer, antimony pent(isooctyl thioglycollate)(Sb(SCH2COOC8H17)5), was synthesized by using antimony trioxide, isooctanol and thioglycolic acid in 2 steps. Firstly, antimony trioxide was oxidized into colloidal antimony peroxide. Then antimony peroxide and isooctyl thioglycollate reacted stoichiometrically for 2 h with the yield of 87%. This compound was used as thermal stabilizer for polyvinyl chloride(PVC). The results show that the thermal stability time is 52min at 200℃ by heat-ageing oven test when adding 2.5% thermal stabilizer to PVC resin. Compared with antimony tris(isooctyl thiolycollate), the initial thermal stability of antimony pent(isooctyl thioglycollate) is better than that of antimony tris(isooctyl thioglycollate), while the long-term thermal stability time is shorter than that of antimony tris(isooctyl thioglycollate). Meanwhile, the synergism of antimony pent(isooctyl thioglycollate) with calcium stearate was studied, indicating that when the mass ratio of antimony pent(isooctyl thioglycollate) to calcium stearate is (2∶1,) the thermal stability time of PVC is 58min. 展开更多
关键词 colloidal antimony peroxide antimony pent(isooctyl thioglycollate) SYNTHESIS PVC thermal stabilizer
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The Research Progress of CO2 Capture with Ionic Liquids 被引量:6
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作者 赵志军 董海峰 张香平 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第1期120-129,共10页
Due to their negligible volatility,reasonable thermal stability,strong dissolubility,wide liquid range and tunability of structure and property,ionic liquids have been regarded as emerging candidate reagents for CO2 c... Due to their negligible volatility,reasonable thermal stability,strong dissolubility,wide liquid range and tunability of structure and property,ionic liquids have been regarded as emerging candidate reagents for CO2 cap-ture from industries gases.In this review,the research progresses in CO2 capture using conventional ionic liquids,functionalized ionic liquids,supported ionic-liquids membranes,polymerized ionic liquids and mixtures of ionic liquids with some molecular solvents were investigated and reviewed.Discussion of relevant research fields was presented and the future developments were suggested. 展开更多
关键词 CO2 CAPTURE ABSORPTION separation ionic liquids DESORPTION SOLUBILITY SELECTIVITY
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In situ Fourier Transform Infrared Spectroscopy Diagnostic for Characterization and Performance Test of Catalysts
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作者 Patrick Mountapmbeme Kouotou 田振玉 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2017年第5期513-520,I0001,共9页
The present work establishes a systematic approach based on the application of in-situ Fourier transform infrared spectroscopy (FTIR) for the investigation of the crystal structure, thermal stability, redox behavior... The present work establishes a systematic approach based on the application of in-situ Fourier transform infrared spectroscopy (FTIR) for the investigation of the crystal structure, thermal stability, redox behavior (temperature-programmed reduction/temperatureprogrammed re-oxidation) as well as the catalytic properties of Co3O4 thin films. The syntheses of Co3O4 were achieved by chemical vapor deposition in the temperature range of 400-500℃. The structure analysis of the as-prepared material revealed the presence of two prominent IR bands peaking at 544 cm-1 (υ1) and 650 cm-1 (υ2) respectively, which originate from the stretching vibrations of the Co-O bond, characteristic of the Co3O4 spinel. The lattice stability limit of Co3O4 was estimated to be above 650℃. The redox properties of the spinel structure were determined by integrating the area under the emission bands υ1 and υ2 as a function of the temperature. Moreover, Co3O4 has been successfully tested as a catalyst towards complete oxidation of dimethyl ether below 340 ℃. The exhaust gas analysis during the catalytic process by in situ absorption FTIR revealed that only CO2 and H2O were detected as the final products in the catalytic reaction. The redox behavior suggests that the oxidation of dimethyl ether over Co3O4 follows a Mars-van Krevelen type mechanism. The comprehensive application of in situ FTIR provides a novel diagnostic tool in characterization and performance test of catalysts. 展开更多
关键词 In situ Fourier transform infrared spectroscopy Diagnostic Thermal stability Redox property Catalytic mechanism
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