4-苯乙炔基苯胺封端聚酰亚胺树脂的合成与性能研究

使用4-苯乙炔基苯胺(4-PEA)作为反应性封端剂,和3,3′,4,4′-二苯醚四酸二酐(ODPA),3,3′,4,4′-联苯四酸二酐(BPDA),1,4-双(4′-氨基-2′-三氟甲基苯氧基)苯(BTPB)和3,4′-二氨基二苯醚(3,4-′ODA)反应合成了系列4-苯乙炔基苯基封端的聚酰亚胺低聚物,对低聚物的化学结构、热性能和熔体粘度以及固化后树脂的热性能等进行了研究.实验结果表明,低聚物均具有一定的结晶性,含有ODPA的聚酰亚胺低聚物较之含有BPDA的低聚物具有更低的熔体粘度,且出现最低熔体粘度的温度更低;固化后的树脂表现出良好的热性能,含有BPDA的树脂具有更高的玻璃化转变温度;系列低聚物中二胺单体的比例对于低聚物的熔体粘度和固化后树脂的热稳定性有一定影响.     

Technological significance of sol-gel process and process-induced variations in sol-gel materials and coatings

A significant aspect of sol-gel technology is the capability it provides to affect the substructure of materials by controlling the nature and the kinetics of chemical reactions. This capability allows us to produce novel materials, design unique molecular and pore morphologies, circumvent high-temperature reactions, and modify material properties. The modifications include strongly thermodynamic-dependent high-temperature properties such as sintering, crystallization, and viscosity in glass and ceramic materials. A particularly exciting area for investigation is the optical-electronic field, where a significant dependence of electro-optical properties and photosensitivity on process-induced molecular-structural variations occurs. Understanding the basis for the creation of structural variations in sol-gel processes should have significant impact on the technologies and systems that use these materials. In this article, some fundamental aspects of alkoxide-based, sol-gel processes and thermochemical bases for process-induced structural variates are discussed.     

Bi4B2O9晶体及其熔体结构的高温原位拉曼光谱研究

利用密度泛函理论计算了Bi₄B₂O₉晶体的常温拉曼光谱, 并通过与实验拉曼光谱对比, 对其振动模式进行了归属. 利用高温原位拉曼光谱研究了Bi₄B₂O₉从常温到750 ℃升温过程中微结构的变化. 随着温度的升高, 晶体的平均键长变长, 键角分布变宽, 熔化后晶体中的BiO₄和BiO₅多面体解体, BO₃构型则保持三配位不变. 运用量子化学从头算法模拟了Bi₄B₂O₉的熔体结构并与实验拉曼光谱进行了对比分析, 发现在Bi₄B₂O₉熔体中B原子团簇为孤立的BO₃构型, Bi ³⁺游离于BO₃之间, 并结合未参与形成BO₃的O原子起到平衡电荷的作用.     

双羟基四配位硅单体的合成

以无定型二氧化硅为起始原料，与乙二醇、氢氧化钾反应，生成高反应活性的 五配位硅钾化合物，并以此为原料与2－氯乙醇反应制备了双羟基四配位硅化合物 。探讨了不同反应条件（如温度、不同反应物摩尔比、催化剂等）对该反应的影响 ，并对合成的化合物做了红外光谱、核磁共振（^1H,^13C)、元素分析、能谱元素 分析等结构表征。     

链状Salen型高分子席夫碱金属配合物的合成及表征

以对苯二甲酰氯为交联剂,利用界面聚合法合成了链状Salen型高分子席夫碱金属配合物PLSBM(M:CoⅡ,MnⅡ,ZnⅡ,CuⅡ),通过元素分析、红外光谱(FT-IR)、扫描电镜(SEM)、电感耦合等离子原子发射光谱(ICP-AES)和X射线光电子能谱(XPS)对结构进行了表征,发现PLSBM呈不规则的链状结构,配位金属离子与配体形成了稳定的配合物后金属离子的结合能增加了0.5～2.1eV。     

熔融酯交换法合成聚碳酸酯的研究

采用熔融酯交换法,以碳酸二苯酯(DPC)和双酚A(BPA)为原料合成聚碳酸酯(PC).考察了乙酰丙酮(HACAC)类金属配合物催化剂的活性,以及催化剂活性与相应金属离子螯合配位作用的关系.以不同乙酰丙酮金属配合物为催化剂合成的PC的特性黏数([η])对相应金属离子二苯甲酰甲烷(DBM)配合物的稳定常数的对数值(lgβ1)作图,得到1个双火山型曲线,证明DPC与BPA的熔融酯交换缩聚反应是受乙酰丙酮阴离子的碱性作用和金属离子的螯合配位作用共同影响的.通过比较用各种催化剂合成的PC的性质,发现乙酰丙酮锂(LiACAC)是一种优良的催化剂,可以用来合成分子量超过40000([η]=0.710 dL.g-1)、低支化物(Fries产物)含量、低分散(PDI=2.12)的PC.以LiACAC为催化剂,考察了催化剂用量、反应物配比、酯交换阶段压力以及温度等条件对反应的影响.最佳反应条件为,LiACAC的用量为1.5×10-4mol/mol BPA、原料配比nDPC∶nBPA=1.08、酯交换阶段压力设在4000 Pa、缩聚反应阶段反应温度为260℃.     

Alternating π‐conjugated block copolymers with precise block length

A Sonogashira polycondensation reaction has been used to synthesize copolymers consisting of alternating oligo(p‐phenyleneethynylene) with a precise block length as an electron‐rich component and 1,4‐bis(2‐phenylene‐2‐cyanovinylene)benzene or 2,6‐bis(2‐pyridinylene‐ethynylene)pyridine as an electron‐poor component. The copolymers differ in the length of the phenyleneethynylene block (trimer or pentamer) and the content of the electron‐poor component. The length of the phenyleneethynylene block has no influence on the maximum wavelength. The electron‐poor cyano‐block component lowers the optical band‐gap energy of the copolymers. The value is equivalent to that of poly(cyano‐phenylenevinylene) (CN‐PPV) (2.3–2.4 eV). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3574–3587, 2005     

EDOT‐diketopyrrolopyrrole copolymers for high bulk hole mobility and near infrared absorption

To obtain novel low‐bandgap materials with tailored hole‐transport properties and extended absorption, electron rich 3,4‐ethylenedioxythiophene is introduced as a comonomer in diketopyrrolo[3,4‐c]pyrrole copolymers with different aryl flanking units. The polymers are characterized by absorption and photoluminescence spectroscopy, dynamic scanning calorimetry, cyclic voltammetry, and X‐ray diffraction. The charge transport properties of these new materials are studied carefully using an organic field effect transistor geometry where the charge carriers are transported over a narrow channel at the semiconductor/dielectric interface. These results are compared to bulk charge carrier mobilities using space‐charge limited current (SCLC) measurements, in which the charge carrier is transported through the complete film thickness of several hundred nanometers. Finally, charge carrier mobilities are correlated with the electronic structure of the compounds. We find that in particular the thiophene‐flanked copolymer PDPP[T]₂‐EDOT is a very promising candidate for organic photovoltaics, showing an absorption response in the near infrared region with an optical bandgap of 1.15 eV and a very high bulk hole mobility of 2.9 × 10^?4 cm² V^?1 s^?1 as measured by SCLC. This value is two orders of magnitudes higher than SCLC mobilities reported for other polydiketopyrrolopyrroles and is in the range of the well‐known hole transporting polymer poly(3‐hexylthiophene). © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 639–648     

Synthesis of dichloro derivatives of linear and cyclic permethyloligosilanes and cyclolinear permethylpolysilane-siloxanes and permethylpolyoxysilane based on them

The reactions of dodecamethylcyclohexasilane with chlorides of I, II, IV—VI, and VIII Group metals were studied as a promising approach to the synthesis of functional oligosilanes. When cyclohexasilane reacts with metal chlorides without a solvent at elevated temperatures, the process is intensified and, in some cases, the selectivity of formation of chloro derivatives of linear and cyclic permethyloligosilanes increases. The cyclolinear permethylpolysilane-siloxanes were prepared by heterofunctional polycondensation of the resulting oligosilanes with bifunctional cyclic and linear permethyloligosiloxanes. Cyclolinear permethylpolyoxysilane was synthesized for the first time by the reaction of 1,3-dihydroxycyclohexasilane with 1,3-dichlorohexamethyltrisilane.     

杨村煤与石油渣油共处理高温缩聚反应特性的研究

用ＧＪ－２型微型反应釜研究了兖州杨村煤与石油渣油在４７０℃时共处理反应的特性，结果表明，杨树煤和石油渣油在高温下进行共处理反应时，宏观表现是缩聚反应占主导地位，程序升温可提高煤的转化率，添加四氢萘到石油渣油中可抑制缩聚反应，而且添加量越大，抑制效果越明显，煤液化产物的重新加氢也会发生一定的缩聚反应，可产生微量结渣。