季戊四醇酯难燃绝缘油的研究

季戊四醇酯难燃绝缘油的研究陈尔凡，肖毅，徐新（沈阳化工学院高分子化工系沈阳１１００２１）关键词　难燃绝缘油，季戊四醇酯，Ｃ_（５－９）混合酸，酯化反应普通绝缘油（矿物油）耐热性差（闪点低），且使用寿命短。故国际上大力开展了难燃绝缘油的研制［１～５］，...     

Application of DSC Method for Thermal Stability and Flammability Assessment of Modified Polyurethanes

Differential scanning calorimetry (DSC) was applied to investigate the thermal behaviour of a series of segmented polyurethanes based on diphenylmethane-4,4'-diisocyanate (MDI), polyoxypropylenediol (POPD) and 3-chloro-1,2-propanediol (CPD)/1,2-propanediol (PD).It has been found that the heat of thermal transition in the range of 250–300°C increases with the amount of CPD, which also causes a decrease of polyurethanes' flammability, characterised by its Limited Oxygen Index (LOI) value. On the basis of obtained results it can be concluded that DSC may be applied for flammability evaluation of segmented polyurethanes.This revised version was published online in November 2005 with corrections to the Cover Date.     

磷杂菲改性腰果酚多元醇的合成及阻燃聚氨酯硬泡性能

采用生物质原料腰果酚和9,10-二氢-9-氧杂-10-膦杂菲-10-氧化物(DOPO)为原料, 合成了一种磷杂菲改性腰果酚多元醇(P-Cardanol-Polyol), 并利用核磁共振氢谱和磷谱对其结构进行了表征. 利用P-Cardanol-Polyol对聚氨酯硬泡(RPUF)进行阻燃改性, 得到一系列阻燃聚氨酯硬泡. 考察了P-Cardanol-Polyol的用量对阻燃聚氨酯硬泡的形貌、 密度、 热导率、 压缩性能、 热稳定性以及阻燃性能的影响. 研究结果表明, P-Cardanol-Polyol对聚氨酯硬泡的密度影响可以忽略不计; 随着P-Cardanol-Polyol的加入, 阻燃聚氨酯硬泡的平均孔径逐渐减小, 热导率也逐渐降低. 未改性聚氨酯硬泡的最大热释放速率和总放热量分别为390 kW/m²和31.9 MJ/m², 阻燃聚氨酯硬泡则降低至340 kW/m²和24.6 MJ/m². 此外, 阻燃聚氨酯硬泡的压缩强度比未改性聚氨酯硬泡提升了约13%. 炭层分析结果表明, P-Cardanol-Polyol能够促进聚氨酯硬泡形成连续致密且具有良好抗热氧化性能的炭层, 有利于减少燃烧过程中可燃性气体的逸出, 从而提升阻燃性能.     

两亲性杂壳聚合物粒子的高效制备及以其作为模板合成金纳米簇合物

将等质量的嵌段聚合物聚乙烯基萘聚丙烯酸和聚氧化乙烯聚丙烯酸（P2VN-b-PAA和PEO-b-PAA）溶解于N,N′-二甲基甲酰胺(DMF)中,加入小分子二元胺（1,2-丙二胺,PDA）,制备出均匀的两亲性杂壳聚合物纳米粒子(MSNPs)。 该粒子以PEO和P2VN混合嵌段为壳层,非共价键交联的PAA嵌段为核,在水相及有机相中均可稳定分散,具有典型的两亲性特点。 扫描电子显微镜和光散射测试结果表明,该杂壳聚合物粒子(MSNPs)的粒径在300 nm左右,分布较均匀,并显示出壳层可塌缩变形的疏松核（软粒子）特征。 以该聚合物粒子(MSNPs)为模板,可以方便制备出金纳米粒子簇合物。     

Synthesis of Mesoporous Lanthanum Phosphate and Its Use as a Novel Sorbent

Mesoporous lanthanum phosphate was synthesized by supramolecular self-assembly of cetyltrimethylammo-nium bromide and lanthanum nitrate following digestion in phosphoric acid.TGA-DTA,XRD and SEM were em-ployed to study the uncalcined and calcined materials.Sorption behavior of Cr(Ⅲ),Mn(Ⅱ),Fe(Ⅲ),Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ),Zn(Ⅱ),Cd(Ⅱ),Ba(Ⅱ),Hg(Ⅱ)and Pb(Ⅱ)cations was studied on such materials in water,3 mol·L~(-1)ammonia,0.01 mol.L~(-1)potassium ferrocyanide and 0.01 mol·L~(-1)potassium ferricyanide solutions.     

Synthesis and Flammability of Bromine-Containing Polybutadiene

COOH-terminated polybutadiene has been converted into COCl-terminated polybutadiene which was further chemically cross-linked with bisphenol-A and tetrabromobisphenol-A. The flammability characteristics of bisphenol-A and tetrabromobisphenol-A resins have been examined using thermogravimetric, ignition temperature and mass burning rate data. Mass burning rate results support that tetrabromobisphenol-A cross-linked polybutadiene is flame retardant compared to the corresponding non brominated compositions.     

超支化聚氨酯的合成及应用

超支化聚合物因其独特的结构和性能逐渐成为聚合物领域的研究热点之一,各种合成超支化聚合物的方法相继被报道。但对于超支化聚氨酯(HBPU)这一类聚合物,由于其官能团的特殊性,很难用传统的方法制得。本文总结了近十几年来制备HBPU的两类主要方法:一种为单单体法(SMM),包括光气法、叠氮化合物法、AA′ B′B2法、高选择性化学反应等;另一种为双单体法(DMM),包括扩链法,低聚物A2 B3法。另外简要介绍了HBPU在固体电解质、相变材料、油墨以及纳米粒子制备等领域的应用。     

含偶氮发色团侧基聚氨酯的合成及表征

偶氮偶合反应;含偶氮发色团侧基聚氨酯的合成及表征;二阶非线性光学材料;制备     

一种新型三肽衍生物改性聚氨酯的合成和应用

合成了一种新型三肽衍生物苯丙氨酸-赖氨酸乙酯-苯丙氨酸（PLP）。以PLP为扩链剂、聚己内酯二醇（PCL）为软段、4,4′-二环己基甲烷二异氰酸酯（HMDI）为硬段,合成了一系列不同三肽含量的聚氨酯（PU-PLP）。通过1H-NMR、FT-IR、TG、DSC和黏接强度等对PLP和PU-PLP的结构和性能进行了研究。结果...     

Composites of Reduced Flammability Based on Amorphous Elastic Polyurethane and Halogen-containing Flame Retardant

Russian Journal of Applied Chemistry - The effect of a mixture of halogen-containing fl ame retardants based on chloroparaffins and 1,1,9-trihydroperfl uorononanol-1 immobilized on a...     

Synthesis of Ultrastable Ag Nanoplates/Polyethylenimine–Reduced Graphene Oxide and Its Application as a Versatile Electrochemical Sensor

Investigations on Ag nanostructures/reduced graphene oxide composites have been frequently reported, yet the morphology control of those loaded Ag nanocrystals is still challenging. We herein develop a facile method to grow triangular Ag nanoplates (AgP) on polyethylenimine‐modified reduced graphene oxide (AgP/PEI‐rGO). The AgP/PEI‐rGO hybrids show unexpected high stability against chloride ions (Cl^?) and hydrogen peroxide (H₂O₂), which is possibly due to the strong interaction between surface Ag atoms with the amine groups of PEI. In the chronoamperometry measurements for detecting H₂O₂, N₂H₄, and NaNO₂, the AgP/PEI‐rGO hybrid shows very wide linear ranges (usually 10^?6–10^?2 mol L^?1 for H₂O₂, N₂H₄, and NaNO₂) and low detection limits (down to ≈1×10^?7 mol L^?1), which demonstrate the promising electrochemical sensor applications of these metal/graphene hybrids with well‐defined morphologies and facets. In addition, this strategy could be extended to the deposition of other noble metals on rGO with controlled morphologies.     

Dimorpholinoacetylene and Its Use for the Synthesis of Tetraaminocyclobutadiene Species

The new diaminoacetylene (DAA) dimorpholinoacetylene ( 3 ) was prepared from 1,1-dimorpholinoethene ( 1 ) by bromination to form the dibromoketene aminal 2 , which upon lithiation afforded 3 through a Fritsch-Buttenberg-Wiechell rearrangement. Heating 3 at elevated temperatures resulted in a complete conversion into the dimer 1,1,2,4-tetramorpholino-1-buten-3-yne ( 4 ), which was used for the synthesis of four-membered cyclic bent allene (CBA) transition-metal complexes of the type [(CBA)ML_n] ( 5 - 7 ; ML_n=AuCl, RhCl(COD), RhCl(CO)₂; CBA=1,3,4,4-tetramorpholino-1,2-cyclobutadiene; COD=1,5-cyclooctadiene). The reaction of 3 with tetraethylammonium bromide gave 1,2,3,4-tetramorpholinocyclobutenylium bromide ( 8 ), which reacted with bromine to form 1,2,3,4-tetra(morpholino)cyclobutenediylium bis(tribromide) ( 9 ). Compound 9 represents the first fully characterized compound containing a tetraaminocyclobutadiene dication and displays a nearly planar C₄N₄ core as shown by X-ray diffraction analysis. Detailed quantum chemical calculations were performed to assess the aromaticity of tetraaminocyclubutadiene dications by employing the Nucleus Independent Chemical Shift (NICS) method and current density analysis.     

醇体系中合成CuGaS2纳米晶及其形貌演变

Using ethylene glycol as solvent and reductant, CuCl2·2H2O, (NH2)2CS and self-prepared GaCl3 as the starting materials, CuGaS2 nanostrucutures were synthesized on a large scale at 220 ℃. Powder X-ray diffraction,transmission electron microscopy, field-emission scanning electron microscope, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy were used to characterize the products. It demonstrated the evolution of the CuGaS2 particles from spherical assemblies to flowerlike morphology, over time,at 220 ℃. Simultaneously, we elucidated the specific roles of reaction temperature, reaction time and solvent in the formation of the final CuGaS2 nanostructures. A possible formation mechanism of CuGaS2 nanostrucutures was also discussed. The room temperature photoluminescence spectrum showed blue-shift and an increase of intensity, with a decrease in the sizes of CuGaS2 particles.     

聚吡咯/还原氧化石墨烯复合物的合成及电容性能

通过原位聚合方法制备不同配比的聚吡咯/氧化石墨（PPy/GO）复合物,将其用NaBH4还原得到聚吡咯/还原氧化石墨烯(PPy/RGO)复合物,采用X射线衍射、红外光谱和场发射扫描电子显微镜（FESEM）对其结构和形貌进行物理表征。 采用循环伏安、恒电流充放电和交流阻抗等电化学方法系统研究了所制备样品的电化学性能。 实验结果表明,在电流密度为0.5 A/g、吡咯（Py）与GO质量比为95∶5时,得到的复合物还原前后比电容分别可达401.5和314.5 F/g,远高于单纯的GO（34.8 F/g）和PPy（267.5 F/g）。 经过1200圈循环稳定性测试后,PPy/RGO复合物比电容保持了原来的62.5%,与PPy和PPy/GO（电容保持率分别为16.8%和46.4%）相比,PPy/RGO表现出更好的循环稳定性能,有望成为超级电容器电极材料。     

阻燃型聚乳酸基聚氨酯的合成与表征

以聚乳酸二醇、六次甲基二异氰酸酯和二溴新戊二醇设计合成出一系列阻燃型聚乳酸基聚氨酯。 通过核磁、凝胶色谱和红外等表征了材料的结构性能。 结果表明,二溴新戊二醇作为扩链剂可满足制备高相对分子质量聚氨酯的要求,材料的热学性能随聚乳酸二醇相对分子质量和硬段质量分数的增加而增加。 同时该类聚氨酯具有较好的力学性能,拉伸强度在50 MPa附近,接近工业级别的聚乳酸。 材料的阻燃性能随着溴质量分数的增加而增强。 当溴质量分数为8.6%,聚氨酯的极限氧指数(LOI)为28,属于难燃级别材料。     

Microwave-Assisted Synthesis and Characterization of Polyurethanes from TDI and Starch

In this work, a microwave-assisted method was developed to prepare polyurethanes from starch or maltodextrin and tolylene-2,4-diisocyanate (TDI). As compared to conventional heating, this new synthetic procedure saves energy, significantly reduces reaction time, and yet entails product yields that are comparable to those of the conventional heating procedure. The reaction products were characterized with NMR, FT-IR, thermogravimetric analysis, and scanning electron microscopy. From these analyses, the polyurethanes made with the conventional and microwave methods are shown to be similar in chemical structure and physical morphology. Furthermore, the ¹H and ¹³C NMR spectra of the starch polyurethanes have been fully assigned for the first time.     

水凝胶/金属纳米粒子复合物的制备及其在催化反应中的应用

金属纳米粒子的表面效应使其在有机催化方面具有广阔的应用前景,但由于金属纳米粒子易团聚而降低了其催化活性,解决金属纳米粒子的团聚问题具有重要的实际意义。水凝胶具有三维网状结构和大量的功能基团,可用于金属纳米粒子催化剂的制备,有利于金属纳米粒子的分散与固定以及提高金属粒子的回收率与重复使用性。本文主要综述了水凝胶（天然水凝胶与合成水凝胶）负载金属纳米粒子复合物的制备及其催化性能的研究,对影响复合催化剂性能的因素进行总结,最后对其存在的问题和将来可能的发展方向进行展望。