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11.
用红外光谱法对热固性酚醛树脂固化过程的研究 总被引:4,自引:0,他引:4
用红外光谱法研究了四种热固性酚醛树脂在固化过程中的化学变化。结果表明热固性酚醛树脂的固化过程,首先是羟甲基发生缩合反应,缩合反应形成醚键是主要的。热固性酚醛树脂在进一步固化时(150—200°)出现了羰基,它的出现不是亚甲基氧化所致,而是部分醚键断裂形成了醛羰基。对热固性酚醛树脂的固化过程的机理进行了讨论。 相似文献
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This review is a concise survey about the works in our laboratory on the polymerization of aromatic and heterocyclic dinitriles, including the polymerization kinetics and mechanism, synthesis of heterocyclic dinitriles, the structure of polymers, and the correlation between the structures of dinitriles and polymerization rates and thermal performances of Polymers. 相似文献
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The polymerization rates of three cyanopyridines catalyzed by cuprous chloride-zinc system are measured, and the structure of the formed polymer is also determined. Compared with aromatic nitrile, cyanopyridines polymerize faster and form polyconjugated polymer with skeleton—(C=N)—_n instead of triazine structure. This chain-polymer possesses semiconductive property, and can be converted into conductive material by thermal treatment. In addition, the polymerization kinetics of 3-cyanopyridine catalyzed by 3-cyanopyridinium perchlorate is investigated. It is found that the polymerization rate is directly proportional to the concentrations of monomer and catalyst, and the activation energy of the polymerization is 103.1 KJ/mol. 相似文献
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The bulk polymerization of benzonitrile catalyzed by Co(Ⅱ), Co(Ⅲ) and Fe(Ⅲ) acetylacetonate was studied. The results of kinetics study show that the rate of polymerization was proportional to first power of the concentration of catalyst and second power of the concentration of monomer. 相似文献
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This paper simulates the dendrite growth process during non-isothermal solidification in the Al-Cu binary alloy by using the phase-field model. The heat transfer equation is solved simultaneously. The thermodynamic and kinetic parameters are directly obtained from existing database by using the Calculation of Phase Diagram (CALPHAD) method. The effects of the latent heat and undercooling on the dendrite growth, solute and temperature profile during the solidification of binary alloy are investigated. The results indicate that the dendrite growing morphologies could be simulated realistically by linking the phase-field method to CALPHAD. The secondary arms of solidification dendritic are better developed with the increase of undercooling. Correspondingly, the tip speed and the solute segregation in solid-liquid interface increase, but the tip radius decreases. 相似文献
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由氰基乙酸酯或丙二腈先制得氰基取代的烯酮缩硫醇, 然后与二胺反应合成了氰基取代的含杂环烯酮缩胺, 测定了它们的UV、IR、^1H及^1^3C NMR等波谱, 并测定了其中两个化合物的晶体结构, 对所得的波谱和结构特性进行了讨论。 相似文献