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991.
992.
993.
首先简单介绍了环氧树脂的工艺原理和SUPCON JX-300X的基本功能,然后对SUPCON JX-300X在环氧树脂生产中如何设计实现环氧树脂工艺中的釜内温度先进控制和进料部分的批量控制的实际应用,进行了比较详细的介绍。 相似文献
994.
Diglycidyl ether of 3,3′,5,5′‐tetramethyl‐4,4′‐biphenyl (TMBPDGE) which has been found great applications in semiconductor packaging was synthesized. The liquid crystalline phases of diglycidyl ether of 4,4′‐dihydroxybiphenol (BPDGE) cured with phenol novolac (PN) were studied by wide angle X‐ray diffraction (WAXD) and polarized optical microscopy (POM). BPDGE was in situ copolymerized with TMBPDGE to improve its thermal and mechanical properties by means of the LC domains retained in the crosslinked networks. The results indicated that a nematic phase was formed and fixed with proper curing schedule when BPDGE was cured with PN that had no neighboring active hydrogens and the LC domains could also be efficiently embedded into the composite systems. Dynamic mechanical properties showed that epoxy networks containing LC domains displayed higher α‐relaxation temperature and linear elastic modulus traces. The impact toughness and Tg were improved with the addition of BPDGE. Scanning electron microscope observation of the fracture surfaces showed that there was a change in failure mechanism in the composite systems. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 相似文献
995.
The high mode-I fracture surface energies, GIC, of structural adhesives can be attributed to their ability to form large crack-tip deformation zones prior to failure. It has been suggested that this feature also controls the dependence of the adhesive bond GIC on bond thickness. The proposed explanation asserted that the physical constraint of the adherents and the nature of the crack-tip stress field in an adhesive joint alter the size and shape of the deformation zone, and this in turn changes the fracture behaviour. To examine this hypothesis, motion pictures were taken of fracture specimens during loading, and the stress whitening that occurred at the crack tip was used to judge the relative dimensions of the deformation zone. The results generally support the hypothesis. Moreover, the pictures furnish a clear image of the deformation zone's growth patterns during loading, and this provides a critical test for future modelling efforts. 相似文献
996.
新型阳离子光固化剂双[(4-二苯硫鎓)苯]硫醚-双-六氟磷酸盐的合成 总被引:4,自引:1,他引:3
以二苯硫醚为主要原料,以过氧化氢为氧化剂,在室温条件下氧化得到了二苯亚砜.然后,二苯亚砜与二苯硫醚在硫酸的作用下,进行缩合反应制备了双[(4 二苯硫)苯]硫醚 双 六氟磷酸盐,收率由文献报道的39%提高到75%;对其结构进行了UV、IR、H NMR和元素分析. 相似文献
997.
The paper discusses the experimental work by the authors investigating bond strength of epoxy adhesives and their efficiency when joining to concrete elements; the epoxies studied were those currently used in the construction industry. Flexural tests were undertaken to determine the mechanical properties of the exposed and the control specimens of three different epoxy adhesives. In addition, the water resistance of concrete/concrete epoxy joints was investigated by comparing bond strength with those of control samples; the maximum period of immersion was one month. A reduction in the glass transition temperature and the stiffness at short immersion time was found for all the adhesives employed, with a subsequent slight increase for prolonged immersion, while the effects on the strengths resulted almost proportional to their initial values. The effect of water on the adhesion of the joints was found to be significant, especially at longer immersion times; the bond strength of concrete–adhesive specimens reduced by 30% after one month of immersion in water. 相似文献
998.
本文以含有不同离子基团的聚酯多元醇为软段,采用丙酮法合成了一系列水性聚氨酯乳液。研究了不同离子基团的聚酯多元醇和不同软段结构对其干膜物理机械性能和吸水率的影响。 相似文献
999.
The water‐based polyacrylate microemulsion for ultrahigh molecular weight polyethylene (UHMWPE) fibers adhesive coating was synthesized by the emulsion polymerization of methyl methacrylate (MMA), butyl acrylate (BA), acrylic acid (AA), and hydroxyethyl acrylate (HEA) in the presence of a composite of sodium lauryl sulfate (SLS), OP‐10, and n‐octyl alcohol (NOA) as the emulsifier. The effects of the mass fraction of emulsifier and the reaction time on the properties of emulsion and its membrane were investigated. When m(BA) : m(MMA) : m(AA) : m(HEA) was 50 : 50 : 3 : 10 (wt ratio) and the mass fraction of emulsifier was 13 wt % and the reaction time was 3 h at 80°C, the latex particle diameter was 30 nm tested by transmission electron microscope (TEM). The Fourier transform infrared (FTIR) spectrometer and differential scanning calorimeter (DSC) were used to characterize the chemical structure and the glass transition temperature (Tg) of microemulsion membrane. The application results showed that this microemulsion was an ideal adhesive coating for UHMWPE fibers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006 相似文献
1000.
改性环氧覆铜板高电性能的研究 总被引:2,自引:0,他引:2
目的:研究高电性有环氧覆铜板的方法。方法:论述获得高电性能覆铜板途径,分析改性聚苯醚应用于改性环氧得到的覆铜板的性能。结果:用改性聚苯醚改性环氧而得的覆铜板具有优异的电性能。 相似文献