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采用新型的含间甲基取代杂萘联苯结构的二胺2-(4-氨基苯基)-4-[2-甲基-4-(4-氨基苯氧基)卜2,3-二氮杂萘-1-酮为单体,与2,6-萘二甲酸(NDA)进行溶液缩聚制备了新型聚芳酰胺,以对苯二甲酸(17PA)为第三单体对聚芳酰胺进行了共缩聚改性,并研究了TPA的含量及结构对聚芳酰胺性能的影响。n(NDA)/n(TPA)为4:6时,共聚物特性黏数最大为1.70dL/g。合成的聚芳酰胺具有良好的溶解性,可溶于N-甲基吡咯烷酮、N,N-二甲基乙酰胺等非质子极性溶剂中,玻璃化转变温度大于320℃,5%热失重温度大于435℃。 相似文献
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本专利制得的化合物可分为下列几类:1.氯化芳腈——尤其是五氯苯甲腈、有三个异构体的四氯苯二腈、三氯三间腈、七氯1-氰化萘,七氯2-氰化萘和八氯4,4′-二氰二苯。2.氯化杂环腈——如氯化腈基吡嗪、氯化腈基嘧啶、氯化腈基1,3,5三嗪、氯化氰基吡啶(美国专利3,325,503)、四氯4-氰基吡啶。 相似文献
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新型耐热双马来酰亚胺改性环氧树脂性能研究 总被引:1,自引:0,他引:1
以4-(4-羟基苯基)-2,3-二氮杂萘-1-酮(DHPZ)为原料,制得含二氮杂萘酮结构的聚芳醚砜预聚物(PPES),再与顺丁烯二酸酐反应得到不同聚合度的含二氮杂萘联苯结构的双马来酰亚胺(PPES-BMI)。采用FT-IR和1H-NMR对其分子链结构进行了表征,测试了聚合物分子质量和溶解性能。通过TGA分析和冲击性能测试研究了不同含量、不同聚合度的PPES-BMI对PPES-BMI/DGEBA复合体系热-力学性能的影响。结果表明,PPES-BMI含量增加,体系初始热分解温度和最大热失重温度上升;PPES-BMI质量分数为35%,DP=20的PPES-BMI/DGEBA共混体系的冲击强度最大,达到2.67 kJ/m2,增幅为75.8%。 相似文献
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以聚己内酯二醇(PCL)、4-(4'-羟基苯基)-2,3-二氮杂萘-1-酮(DHPZ)、4,4'-二苯基甲烷二异氰酸酯(MDI)及1,4-丁二醇为原料,采用一步法设计合成了含二氮杂萘联苯结构聚氨酯溶液。采用红外光谱仪、X射线衍射仪、热重分析仪以及万能力学试验机,考察了DHPZ含量对聚氨酯胶膜耐高温性能和力学性能的影响。结果表明,二氮杂萘联苯结构提升了聚氨酯膜的耐热性能,DHPZ质量分数从0到5%,初始热分解温度(T_d~(1%))可提高10~20℃;当DHPZ质量分数为2%时,聚氨酯膜力学性能较优,其拉伸强度达到67. 1 MPa,断裂伸长率为860%,弹性模量为4. 5 MPa。 相似文献
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《精细与专用化学品》2002,10(6)
农 药杀虫剂伏虫隆的合成/刘长春//精细化工中间体.-2001,31(6).-28~29,33 以1,2,4-三氯苯为原料,经硝化、氯化、氟化和还原等步骤合成了5-二氯-2,4-二氟苯胺,产率为72%;以2,6-二氯苯腈为原料,经氟化和水解制得2,6-二氟苯甲酰胺,产率为92%;将2,6-二氟苯甲酰胺先用二(三氯甲基)碳酸酯酰化后制得2,6-二氟苯甲酰异氰酸酯,再与3,5-二氯-2,4-二氟苯胺加成得到苯甲酰脲类杀虫剂伏虫隆,产率为93%。水杨酸双嘧啶(钠)的合成新方法/杨伟等//江苏农药.-2001,(4).-7~8 相似文献
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《Ceramics International》2020,46(9):13695-13703
Manganese–copper ferrite (MCFO) and dysprosium (Dy)-doped manganese–copper ferrite nanocomposites (Mn0.5Cu0.5DyxFe2−xO4) (x = 0, 0.05, 0.10, and 0.15) were synthesized by sonochemical method. Crystal structure and the structural parameters of the MCFO were analyzed based on the doping concentration of Dy ion. It was observed that the average crystalline size of the synthesized nanocomposite decreases when the concentration of Dy increases. The existing spherical surface morphology of the MCFO and Dy-doped MCFO nanocomposites were obtained through scanning electron microscopy. In the UV spectrum, the pristine MCFO sample showed an absorbance peak at 743 nm whereas the absorbance values of Dy-doped ferrite nanocomposite considerably shifted (blue) toward a lower wavelength (231–222 nm). The dielectric parameters of all ferrite nanocomposites were studied in the frequency range of 100 Hz to 5 MHz. The dielectric spectrum revealed that dielectric constant and loss tangent decreased with increased doping concentration of Dy ion. The saturation magnetization also changed with Dy doping in MCFO. The impact of Dy on manganese–copper ferrite changed the optical, dielectric and magnetic properties of the prepared binary ferrite nanocomposite, which can be used for microwave-absorbing material applications. 相似文献
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E. S. Zainudin S. M. Sapuan K. Abdan M. T. M. Mohamad 《Polymer-Plastics Technology and Engineering》2013,52(1):97-101
Mechanical strengths of a banana pseudo-stem (BPS) fiber and unplasticized polyvinyl chloride (UPVC) composite were evaluated to assess the possibility of using it as a new material in engineering applications. Samples were fabricated by the compression molding process with reference to the effect of filler loading. The samples were submitted to mechanical tests to measure tensile, flexural, and impact properties of the composites. The nature of adhesion between the matrix and the reinforcement and information relating the structure of mechanical properties can be obtained by scanning electron microscopy (SEM) assessment of the composite fracture surface. The mechanical properties show that the composites did not have good adhesion between filler and matrix; on the other hand, the filler insertion improved the flexural modulus and the material rigidity. 相似文献
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核壳纳米粒子作为复合纳米粒子一个重要的分支,由于其光、磁和催化等方面的优异性能,近年来引起了人们广泛的关注.本文主要介绍了核壳纳米粒子的制备方法及诸多性能,并对核壳纳米粒子的发展进行了展望. 相似文献
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王丽 《合成材料老化与应用》2014,(4):15-17
分别以聚四氢呋喃醚二醇(PTMEG)、聚氧化丙烯二醇(PPG-1000)为软段,以二苯基甲烷二异氰酸酯(MDI-50、MDI-100LL),以及扩链剂1,4-丁二醇(BDO)、三羟甲基丙烷(TMP)为硬段,采用预聚体法制备了聚氨酯弹性体。并系统研究了聚氨酯体系中各组分的种类对材料机械性能和阻尼性能的影响。 相似文献
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《Ceramics International》2020,46(2):1974-1981
Nowadays, complicated preparation processes and harsh sintering conditions wave transparent ceramics limit its further development. To solve this problem, we explore a promising precursor by adopting a polymerization-pyrolysis method to prepare porous Si–Al–O–B ceramics at a mild sintering condition (1000 °C). The porous Si–Al–O–B ceramics exhibits enhanced wave transparency at 10–16 GHz with a low dielectric constant (<3), a low loss angle tangent value (<0.01), and simultaneously, a relative high flexible strength of 82 MPa. According to the results of the XRD and FTIR analysis, porous Al4B2O9 crystallization dispersed in the amorphous SiO2 matrix constructs the main phases of the products. The changes of Al and B elements are confirmed to have an effect on the phase compositions and micro structure of the composite ceramics, which obviously affect the mechanical and dielectric properties of the derived ceramics. The as-prepared porous Si–Al–O–B ceramics could be a potential candidate for next generation electronic window materials due to its low dielectric constant and loss angle tangent value, as well as high flexible strength. 相似文献
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Effects of support and additive on oxidation state and activity of Pt catalyst in propane combustion 总被引:1,自引:0,他引:1
The effects of support and additive on the oxidation state and catalytic activity of Pt catalyst in the low temperature propane combustion were systematically investigated on Pt/MgO, Pt/Al2O3 and Pt/SiO2–Al2O3. The catalytic activity varied much with both support materials and additives. The catalyst on the more acidic support showed higher activity, and the catalytic activity on every support materials increased as the electronegativity of additives increased, while some additives decreased the activity. The oxidation state of platinum, estimated by white line intensity of Pt LIII-edge XANES spectrum, also varied with the support and additives, and additives with higher electronegativity greatly prevented the platinum from its oxidation under oxidising atmosphere. Among almost all the catalysts with various supports and various additives, a clear relationship was observed between the oxidation state of platinum and the catalytic activity; the more metallic platinum showed higher activity. Thus, it was concluded that the total electrophilic/electrophobic property derived from those of the support and additive controls the oxidation state of platinum, which intensively affects the catalytic activity; i.e. higher electrophilic property provides less oxidised platinum, resulting in high catalytic activity. The mechanism of this effect was also discussed on the basis of thermochemical data, and it was proposed that the electrophobic materials promote the noble metal oxidation since the noble metal oxo-anion such as PtOδ− is more stabilised with electrophobic cation. 相似文献