硝化纤维素键合螺噁嗪光致变色材料的制备与研究

通过接枝共聚方式,将螺噁嗪类光致变色基团引入硝化纤维素,得到了一种均相光致变色功能高分子材料。利用核磁共振碳谱、红外光谱对其结构进行了表征。利用紫外-可见吸收光谱研究发现,产物在丙酮溶液中具有良好的光致变色性质,并且显色体消色热稳定性显著增强。新材料良好的脂溶性和光致变色性使其更具实用潜力。     

具有光致变色功能的纤维素接枝共聚物的制备与表征

以纤维素(Cell)为原料,通过原子转移自由基聚合(ATRP)在纤维素主链上接枝了4种乙烯基单体,然后通过酯化反应接枝螺吡喃衍生物(SP-OH),得到具有光致变色功能的纤维素接枝共聚物。采用核磁谱图、红外光谱、溶解性测试、紫外吸收光谱对所得样品的结构和性能进行表征。结果表明,所制备的具有光致变色功能的纤维素接枝共聚物可以在多种有机溶剂中溶解,并且具有良好的光致变色性能及循环使用的稳定性,在紫外光照射8 min后由白色变为深紫色,并且可以保持12 h不褪色。     

吲哚啉螺萘并(噁)嗪光致变色化合物的合成研究

以β-萘酚经亚硝化反应得到中间体1-亚硝基-2-萘酚;以苯肼、3-甲基-2-丁酮为原料合成得到2,3,3-三甲基-3H-吲哚,经碘甲烷季铵盐化后在碱性条件下与1-亚硝基-2-萘酚反应得到1,3,3-三甲基吲哚啉螺萘并(噁)嗪光致变色化合物.通过1H NMR、IR和元素分析确证了中间体和目标分子的结构;讨论了温度对1-亚硝基-2-萘酚合成的影响、制备吲哚季铵盐时溶剂的选择以及目标化合物的合成与光致变色机理.目标化合物的甲醇溶液经紫外光照射后由无色变为淡兰色,显示了良好的光致变色性能.     

吲哚啉螺噁嗪光致变色化合物的研究进展

吲哚啉螺噁嗪以相对较高的化学稳定性、光敏性和抗疲劳性,可应用在光信息记录、光致开关、传感器、油墨印刷、防伪标识、光致变色纺织物和镜片等领域,从而希望成为实用性的光致变色材料之一,近年来引起了人们的浓厚兴趣。本研究从合成方法、光致变色机理、分散介质对其影响和新型吲哚啉螺噁嗪等方面入手,对其研究现状和动向进行综述,并展望了吲哚林螺噁嗪光致变色化合物的发展前景。     

羧甲基纤维素与丙烯酸和丙烯酰胺共聚接枝研究

以羧甲基纤维素钠、丙烯酸、丙烯酰胺为原料，通过自由基接聚合制备了高吸水树脂，分别考察了各种制备条件如聚合温度，反应时间，原料浓度，原料配比，引发剂浓度等因素对高吸水树脂吸收能力的影响，确定了最佳制备条件，制备的高吸水树脂吸收蒸馏水高达900倍左右。     

羧甲基纤维素与丙烯酰胺接枝共聚及共聚物的性能

研究了羧甲基纤维素-丙烯酰胺接枝共聚反应。优化反应条件为:单体浓度20%,引发剂用量300m g/L,初始温度40℃,初始pH值8。通过红外光谱分析、热分析、X射线衍射分析对接枝共聚物结构进行了验证,并对接枝共聚物特性黏数和大分子回旋半径进行了研究。实验得出接枝共聚物回旋半径随聚丙烯酰胺回旋半径与羧甲基纤维素回旋半径变化的关系式,同时证明接枝共聚物在特性黏数、抗温及抗盐性质方面均优于羧甲基纤维素和聚丙烯酰胺。     

螺噁嗪的光开关特性对聚合物电致发光性能的影响

基于螺噁嗪化合物光致变色过程中的光开关特性,将光致变色螺吲哚菲并噁嗪化合物(SO)掺杂到主体电致发光材料聚[2-甲氧基-5-(2’-乙基己氧基)-对亚苯基亚乙烯](MEH-PPV)中,制成结构为ITO/PEDOT:PSS/MEH-PPV:SO/LiF/Al的发光二极管,初步探讨了光照对发光二极管性质的影响。通过光致变色反应,SO的开环成色体可充当注入载流子的陷阱而影响二极管的性质。所以,紫外光照前后MEH-PPV发光二极管的电致发光性质,包括电流、亮度、发光强度等性质,通过螺噁嗪化合物分子的光开关特性而变化。     

超支化环氧树脂改性苯并(噁)嗪树脂的制备与性能

采用兼有脂肪族和芳香族结构的超支化环氧树脂(HBER)增韧改性苯并(噁)嗪树脂(MDA),制备出不同质量比的MDA/HBER均相共混体系.通过傅里叶变换红外光谱、差示扫描量热及动态力学性能分析仪研究了共混体系固化行为和交联网络结构.利用流变仪对共混体系进行动态黏度测试,结果表明在60～190℃之间出现一段较宽的低黏度平台.力学生能测试表明,当HBER质量分数为10％时,共混固化物弯曲性能最优,韧性最佳.共混固化物断面形貌呈现出原位增韧增强特征.     

高性能苯并(噁)嗪基复合材料研究进展

综述了近年来国内外在苯并(噁)嗪树脂基复合材料方面的研究进展,重点介绍了以苯并(噁)嗪为基体的复合材料在耐热、增韧、增强等方面包括化学改性和物理共混研究进展,并初步判断了今后以苯并(噁)嗪树脂为基体的复合材料的发展方向.     

Synthesis and characterization of novel liquid crystalline polymers containing cholesteryl pendant groups

In order to investigate the chiral effect of cholesteryl pendant groups on the induction of the cholesteric phase, a new cholesteryl-containing liquid crystalline monomer was synthesized and copolymerized with an achiral comonomer in various molar ratios. The layer-like arrangement of the smectic mesophase with different monomeric compositions of copolymers was investigated using an X-ray diffraction analysis. The cholesteric liquid phase was induced by the chiral segments; the dependence of the reciprocal central reflection wavelength on the mole fraction of the chiral monomer for copolymers was investigated. This paper demonstrates the effect of chiral pendant groups on the induction of the cholesteric phase and layered molecular arrangement of side-chain liquid crystalline polymers.     

Synthesis and properties of novel chiral side-chain liquid crystalline polysiloxanes containing different chiral pendant groups

Two novel chiral liquid crystalline monomers, and a series of their corresponding chiral side-chain polymers (P₁–P₇) based on poly(methylhydrogeno)siloxane have been prepared. The chemical structures and liquid crystalline properties of the synthesized monomers and polymers have been investigated using various experimental techniques. Thermal analysis shows that all polymers have wide mesophase temperature ranges with a high thermal stability. With the increase of M₂ molar ratio in the polymer systems, the isotropic phase transition and glass transition temperatures of all polymers increase, and the temperature ranges of N* phase and mesophase become broad. The effect of cholesteryl mesogens on mesophase behaviors, optical properties, and molecular arrangement of LC polysiloxanes and their advanced applications have also been discussed. For homopolymer P₁, it shows a single S_A phase. With increasing the content of M₂ in the polymer systems, P₂ and P₃ reveal a S_A–N* phase transition when they are heated, and P₄–P₇ reveal a N* phase. For N* phase polymers P₄–P₇, the reflection wavelengths exhibit blue shift, suggesting that the pitch decreases with a decrease in the amount of the smectic domains induced by the M₁. The reflection wavelengths of P₄–P₇ are almost across the entire visible region when they are heated, which offer stremendous potential for various optical applications. For P₂ and P₃, the reflection wavelengths show a very steep change around the temperature of the S_A–N* phase transition, which can be used as thermally sensitive liquid crystal devices requiring fast response, such as sensors, and thermally induced tuning.     

羧甲基纤维素钠模板法制备纳米硒

报道了羧甲基纤维素钠存在下制备纳米硒的方法,得到了球形、棒状和线状纳米硒。研究了反应时间、反应物浓度、温度、超声等实验条件对产物粒度大小、形貌的影响,采用光谱法、透射电镜、扫描电镜、X射线衍射等手段对产物进行了表征。     

Langmuir-Blodgett films of ethylenedithiotetrathiafulvalene derivative containing hydroxyl groups

Langmuir-Blodgett (LB) films of an ethylenedithiotetrathiafulvalene (EDT-TTF) derivative containing hydroxyl groups, 4, 5-bis(11-hydroxyundecylthio)-4′, 5′-ethylenedithiotetrathiafulvalene were deposited without using stabilizer molecules. Doping of the film with iodine leads to oxidation of EDT-TTF moiety as evidenced by UV-vis and IR spectroscopy. X-ray diffraction studies reveal the presence of layered arrangement of the EDT-TTF derivative molecules in the LB film. Cyclic voltammetry studies indicate that the electrochemical oxidation of the EDT-TTF derivative in its LB film is irreversible. Due to the insulating nature of the alkyl chains, only the first layer of the LB film was found to be redox-active. The electrical conductivity of the 25 layer LB film was found to increase by two orders of magnitude on doping with iodine. On equilibrating the doped film in air, the conductivity gradually reduced with time and finally reached the conductivity of undoped film. This reversibility could be because of the steric hindrance induced by the two long alkyl groups. The alkyl chains help in rendering the EDT-TTF molecule amiable to LB film formation but are found to reduce the electrical conductivity of the films and also cause instability of the doped state. The hydroxyl groups at the end of the alky chain impart amphiphilic nature to the molecules and help in stabilizing the film at the air-water interface.     

磺化含侧苯基杂萘联苯聚醚砜质子交换膜材料的合成与性能

以4-(3-苯基-4-羟基苯基)-2,3-二氮杂萘-1-酮、4-(4-羟基苯基)-2,3-二氮杂萘-1-酮和4,4’-二氯二苯砜为单体,合成了一系列含侧苯基杂萘联苯聚醚砜,然后以浓硫酸为磺化剂,制备磺化含侧苯基杂萘联苯聚醚砜(SPPES-P)。采用FT-IR、1 H NMR对聚合物的结构进行了表征,表明磺酸基被成功地引入到聚合物侧链苯基上。采用溶液法制备了SPPES-P质子交换膜。考察了SPPES-P膜的吸水率、溶胀率、质子传导率,以及甲醇渗透性能和耐氧化性能,SPPES-P膜具有较好的阻醇性和耐氧化性能。     

新型含氰侧基可溶性聚芳酯的合成与表征

以1,2-二氯乙烷(DEC)为溶剂,将自制的新型含氰基芳二酰氯2,6-二(3-氯甲酰苯氧基)苯甲腈(BM-ClPOBN)与各种芳香二酚进行缩聚反应,获得一系列新型含氰侧基聚芳酯.用红外(FT-IR)、元素分析及热失重分析(TGA)等方式对新型聚芳酯的结构与性能进行表征.结果表明,聚合物具有预期结构且热失重分解温度(5%)为385398℃,具有良好的热稳定性.溶解实验表明,聚合物除了可溶解于N-甲基吡咯烷酮(NMP)、N,N-二甲基乙酰胺(DMAC)及N,N-二甲基甲酰胺(DMF)等强极性溶剂外,也能在一些普通溶剂如三氯甲烷(CHCl3)、四氢呋喃(THF)及1,2-二氯乙烷(DEC)中,表现出良好的溶解性.     

吲哚啉螺吡喃的合成及其光致变色性质研究

从小分子出发通过一系列的合成步骤,最终合成了3,3-二甲基-N-乙基-6’-硝基苯并螺吡喃(SP1)、3,3-二甲基-N-乙基-5-氯-6’-硝基苯并螺吡喃(SP2)和3,3-二甲基-N-乙基-5-甲氧基-6’-硝基苯并螺吡喃(SP3)3种未见文献报道的螺吡喃。通过元素分析、红外光谱、核磁共振等手段对合成的部分中间体和目标产物的结构进行表征,并应用紫外-可见吸收光谱对其光致变色性进行了研究。     

Dosimetric properties of tungsten-containing complexes of carboxymethyl cellulose

A study is made of the change in the optical properties of polymer compositions based on W-containing complexes of highly substituted carboxymethyl cellulose under the action of ionizing radiation (α-particles,⁶⁰Co γ-rays). It is shown that film layers based on the complexes mentioned can be used as radiochromic materials for α-radiation dosimetry in the dose range of 4·10²–5.1·10⁵ Gy. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 73, No. 2, pp. 443–446, March–April, 2000.