含硅聚酰亚胺的合成及性能研究

合成了一类含硅二胺双氨丙基四甲基二硅氧烷,并将其与芳族二胺和芳族四酸二酐共聚,得到了一系列不同配比的含硅聚酰亚胺。通过差热分析(DSC)和热重分析(TGA),表明引入有机硅链段能有效地改善聚酰亚胺的性能。共聚物的玻璃化转变温度(Tg)符合Kwei方程。     

含硅聚酰亚胺的合成与性能

含硅聚酰亚胺由于具有可溶性、粘合性、吸湿性以及电绝缘性等方面的优势,近年来逐渐成为聚酰亚胺改性研究的热点。本文主要综述了近年来主链型含硅聚酰亚胺、侧链型含硅聚酰亚胺以及聚酰亚胺含硅无机复合材料的合成方法及其改性性能,并对含硅聚酰亚胺的研究发展进行了展望。     

含硅聚酰亚胺的合成与性能

介绍了含硅聚酰亚胺的若干不同合成和改性方法及相应产物的性能特点.     

硅二极管内层聚酰亚胺保护胶的研制

由聚硅氧烷二胺、芳香族二胺、芳香族二酐溶液缩聚合成的含硅聚酰亚胺应用于硅二极管内层绝缘保护,显示出良好的应用前景。     

含硅阻燃剂的新进展

硅化合物被期待作为新型阻燃剂。它可完全不依赖卤素和磷化合物而发挥阻燃作用。最近有关硅阻燃剂的文章和专利成为新热点，几乎所有组成的硅化合物都被用作阻燃剂研究过。含硅化合物不管是作为聚合物的添加剂，还是与聚合物组成共混物，都具有明显的阻燃作用。     

含硅农药的开发历史、现状与展望

硅广泛存在于地壳中,与碳同族.它还是植物所必需的微量元素,且无固有毒性和残留风险.然而,含硅化合物作为农药的应用却并不多见.对含硅农药开发的历史沿革进行了回顾,并对含硅农药的商业化品种进行了介绍,同时对该类农药的开发前景进行了展望,旨在为含硅农药的开发提供参考并促进其应用.     

含羟基聚酰亚胺改性环氧胶的制备及性能研究

将3,3'-二氨基-4,4'-二羟基联苯(DADHBP)、2,2-双(3-氨基-4-羟基苯基)六氟丙烷(BAH-PFP)和3,3',4,4'-四羧酸二苯醚二酐(ODPA)、3,3',4,4'-四羧酸二苯甲酮二酐(BTDA)单体聚合,再经亚胺化得到含羟基聚酰亚胺(HPI)粉末,采用傅里叶红外光谱对其进行了表征。由HPI、烯丙基双酚A、双马来酰亚胺、2-乙基-4-甲基咪唑与N,N,N',N'-四缩水甘油基-4,4'-二氨基二苯甲烷(TGDDM)共聚反应制得胶粘剂,并对胶粘剂的热性能、力学性能及吸水性进行了研究,结果表明:该胶拉伸剪切强度为21.1 MPa,固化后吸水率为0.49%。通过凝胶化时间法计算胶粘剂的表观活化能为64.5 kJ/mol。     

含硅西佛碱的合成

介绍了含硅西佛碱的合成,制备了8种含硅西佛碱。用^1H—NMR、^13C—NMR对合成的化合物进行表征。目标分子为Ph—CH=NCH2CH2CH2Si(OCH2CH3)3;Ph—CH=NCH2CH2NHCH2CH2CH2Si(OCH2CH3)3;o-HO-Ph—CH—NCH2CH2CH2Si(OCH2CH3)3;o-HO-Ph—CH=NCH2CH2NHCH2CH2CH2Si(OCH2CH3)3;2,4-Cl-Ph—CH=NCH2CH2CH2Si(OCH2CH3)3;2,4-Cl-Ph-CH=NCH2CH2NHCH2CH2CH2Si(OCH2CH3)3;p-NO2-Ph-CH=NCH2CH2CH2Si(OCH2CH3)3;P-NO2-Ph-CH=NCH2CH2NHCH2CH2CH2Si(OCH2CH3)3。     

含硅皮革助鞣剂ASN的研究

本文介绍了含硅皮革助鞣剂ＡＳＮ的合成、性能与应用。该助鞣剂可大大减少鞣剂废液中铬的含量，减少铬鞣剂用量３０％～４０％。     

ICP—AES法测定高硅钢中的硅

研究了用ICP-AES法快速测定高硅钢中的硅,确定了最佳测定条件.在此条件下测定,获得满意结果.实验结果表明,该方法简便、快速、灵敏,检出限为0.000 9 μg/mL;RSD＜0.5 %;回收率为99 %～101 %,结果令人满意.     

粒子弥散强化氮化硅基陶瓷

运用晶界工程理论，选择能形成高耐炎度晶界相的Ｙ２Ｏ３和Ｌａ２Ｏ３双稀土氧化物为Ｓｉ３Ｎ４陶瓷烧结助剂，材料具有优异的高温强度。第二相碳化硅粒子的引入有效地改善了氮化陶瓷的显微结构和力学性能。以无压烧结工艺制备的高性能α／β－Ｓｉａｌｏｎ复相陶瘊等在实际应用中获得良好效果。     

含硅三烃基锡二茂铁羧酸酯的合成及生物活性

合成了１４种含硅三烃基锡二茂铁羧酯酯,通过元素分析、ＩＲ,＾１ＨＮＭＲ表征了这些化合物的结构;化合物的生物活性实验表明,硅原子上到代基较小的化合物具有较好的生物活性。     

Synthesis and Light‐Emitting Properties of New Polyimides Containing Ethynylene Units in the Main Chain

Two new polyimides (ODA‐PI and HDA‐PI) having 1,4‐phenylenediethynylene unit and octyloxy groups were synthesized. Judging from inherent viscosities of their precursor PAAs (1.42 and 1.62 dL · g^?1), the two PIs were very high in molecular weight. Casting and thermal imidization of PAAs results polyimides with good‐quality films. They were stable up to 364 °C and showed no crystallites. UV‐vis and PL spectra in NMP solutions of both PIs showed maxima at 442 and 501 nm, respectively, while PL spectra in ≈10 µm thick films exhibited a maximum at 540 nm. CV indicates that two PIs were electrochemically active in redox region. The devices with construction of ITO/PEDOT/PIs/BAlq₃/LiF/Al exhibited turn‐on voltages of 6.5 V in ODA‐PI and 7.5 V in HDA‐PI and emitted a bright bluish‐green light. ODA‐PI and HDA‐PI showed maximum luminescence of 256 and 316 cd · cm^?2, respectively, at the same voltage of 12 V.

     

Deposition of Erbium Containing Film in Porous Silicon from Ethanol Solution of Erbium Salt

Electrochemical treatment of porous silicon (PS) in ethanol solution of Er(NO₃)₃ was investigated to obtain material suitable for optoelectronic application. The voltammograms of n⁺-type and p-type PS vs. an Ag/AgCl reference electrode were examined and compared with these of a Pt electrode. The basic cathode reactions were marked out the voltammograms: (i) the formation and the adsorption of atomic hydrogen; (ii) the formation of molecular hydrogen; (iii) the electrolysis of water and ethanol. No zones relating to on electrochemical transitions of Er ions were revealed on the voltammograms. Nevertheless, with the cathode polarization, the formation of an Er-containing deposit was observed at the surface of the cathode. The IR and SIMS analysis were used to study the composition of the deposits. The scheme of the electrochemical and chemical reactions at the cathode is discussed.     

含氟聚甲基丙烯酸甲酯合成及其性能研究

以六氟丙烯为起始原料，经齐聚反应、亲核加成反应、氯磺化反应和催化聚合反应制备了含氟聚甲基丙烯酸甲酯。所合成的含氟聚甲基丙烯酸甲酯具有分子量可以通过单体转化率控制、分子量分布窄的特点，添加1％左右的该含氟聚合物可以显著降低聚甲基丙烯酸甲酯薄膜的表面张力。     

氮化硅结合碳化硅耐火材料的氧化

氮化硅结合碳化硅耐火材料高温氧化后，其抗折强度有所提高，但经扫描电镜观察，材料断面结构已发生了明显的变化。该材料长时间在氧化气氛中使用，可靠性将下降。     

湖南省硅肥资源调查研究报告

介绍了硅肥的肥效，分析了湖南省三大硅肥资源〈电炉黄磷炉渣、含锰炉渣、小氮肥造气炉渣〉的数量、品位及应用前景。     

Suppressing Hydrogen Evolution by Aqueous Silicon Powder Dispersions by Controlled Silicon Surface Oxidation

Aqueous silicon dispersions are used to produce pyrotechnic time delay compositions. The propensity of silicon to react with water and to produce hazardous hydrogen gas must be suppressed. To this end, the effect of air heat treatment temperature on the rate of corrosion of silicon was investigated. It was found that four hour heat treatments at temperatures below 350 °C provided significant passivation. This is attributed to the removal of the hydroxyl groups present on the SiO₂ surface scale layer. It was found that thickening the silica layer, by heat treatment at higher temperatures, causes a further reduction in the amount of hydrogen released. However, differential thermal analysis (DTA) studies showed that excessive silicon surface oxidation increased the ignition temperature and reduced the heat release of a near‐stoichiometric silicon‐lead chromate pyrotechnic composition.