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31.
阻燃增塑剂溴化及溴氯化石蜡的合成工艺 总被引:1,自引:1,他引:1
综述了阻燃增塑剂溴化及溴氯化石蜡的各种合成工艺路线,讨论了相应的合成反应机理.包括反应历程和有关化学热力学计算,简要介绍了安徽省化工研究院已工业化的溴化及溴氯化石蜡合成工艺的特点。 相似文献
32.
聚乙烯复合阻燃体系的研究及应用进展 总被引:2,自引:0,他引:2
综述了近年来国内外阻燃聚乙烯(PE)用有协同作用的复合阻燃体系:(1)卤-锑体系;(2)磷-氮体系;(3)金属氧化物体系;(4)膨胀型体系;(5)其他类等5类复合阻燃体系的研究和应用情况。 相似文献
33.
分析了热处理前后丙烯腈/溴乙烯共聚纤维的热性能与溴乙烯含量、升温速率或热处理时间的关系,并对纤维的阻燃性与溴含量或热处理时间关系进行了研究。结果表明,溴含量的增加或热处理时间的延长对热稳定性和阻燃性的提高有较大影响,而且经热处理后纤维的阻燃性与溴无关。 相似文献
34.
The flame‐retardant and smoke‐suppressant properties of inorganic tin compounds such as zinc hydroxystannate (ZHS) and zinc stannate (ZS) were investigated in a comparison with alumina trihydrate, magnesium hydroxide, and Sb2O3 through the limiting oxygen index test and smoke density test. The flame‐retardant mechanisms were studied through the char yield test, SEM, quantitative analysis, thermogravimetry and differential thermal analysis. The thermal degradation in air of flexible PVC treated with the above compounds was studied by thermal analysis from ambient temperature to 800°C. The results showed that tin compounds such as ZHS and ZS could be used as a highly effective flame retardant for flexible PVC, and it appears that the tin compound may exert its action in both the condensed and vapor phases, but mainly in condensed phases as a Lewis acid. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1469–1475, 2005 相似文献
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The flame spraying process, which is a common industrial thermal spraying application, has been analyzed by means of three-dimensional
computational fluid dynamics (CFD) simulations. The process used at the Volvo Aero Corporation for the coating of fan and
compressor housings has been modeled. The process uses the Metco 6P torch (Metco, Westbury, NY), which ejects a mixture of
acetylene and oxygen at high speed through a ring of 16 orifices to form the flame. A stream of argon gas flowing through
an orifice in the center of the ring carries a powder of nickel-covered bentonite through the flame to the spray substrate.
The torch is cooled by a flow of air through an outer ring of 9 orifices. The simulation emulated reality closely by including
the individual inlets for fuel, cooling air, and injected particles. The gas combustion was simulated as a turbulent, multicomponent
chemically reacting flow. The standard, two-equation k-ε turbulence model was used. The chemical reaction rates appeared as
source terms in the species transport equations. They were computed from the contributions of the Arrhenius rate expressions
and the Magnussen and Hjertager eddy dissipation model. The first simulations included several intermediate chemical substances
whose predicted concentration agreed favorably with measurements. Later, more simplified simulations incorporated only the
global chemical reaction involving the initial and the final products, with corrections to the thermal properties being made
to account for the missing intermediaries. The gas velocity and temperature fields predicted by the later simulations compared
satisfactorily to those predicted by the earlier, more elaborate, ones. Therefore, the final simulations, which incorporated
injected particles, were conducted employing the simplified model with only the global reaction. An in-house finite difference
code was developed to calculate particle properties. Allowance was made for elliptical shapes, phase changes, and internal
heat transfer with regard to the composite material. The particle velocities and temperatures predicted by the final simulations
compared fairly well with experimental results obtained with the optical DPV2000 system. 相似文献
39.
用氧乙炔焰加熔剂助熔一步法在12Cr1MoV珠光体耐热钢高温高压阀门密封面基体上喷熔Fe547B合金粉末,对喷熔工艺及喷熔层的硬度、时效硬化特性、热耐久性能、抗擦伤性能等性能进行了较系统的试验研究。证明用喷熔Fe547B合金粉末工艺修复电站高温高压阀门密封面裂纹是可行的。 相似文献
40.
以Ti-B4C-C团聚粉和Ni-Al“自粘结”复合粉的混合物为自蔓延反应火焰喷涂体系,在45钢基体表面制备Ti(Cx,Ny)-TiB2和NimAln梯度过渡的复相陶瓷涂层,分析研究了梯度过渡涂层的显微组织结构与耐磨性。研究表明:Ti(Cx,Ny)-TiB2复相陶瓷与NimAln金属间化合物实现了沿涂层厚度方向的梯度过渡连接。梯度过渡陶瓷涂层的耐磨性是普通45钢耐磨性的14倍。 相似文献