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1.
Thermosetting materials are widely used as encapsulation in the electrical packaging to protect the core electronic components from external force, moisture, dust, and other factors. However, the spreading and curing behaviors of such kind of fluid on a heated surface have been rarely explored. In this study, we experimentally and numerically investigated the spreading and curing behaviors of the silicone(OE6550 A/B, which is widely used in the light-emitting diode packaging) droplet with diameter of ~2.2 mm on a heated surface with temperature ranging from 25 ℃ to 250 ℃. For the experiments, we established a setup with high-speed camera and heating unit to capture the fast spreading process of the silicone droplet on the heated surface. For the numerical simulation, we built a viscosity model of the silicone by using the Kiuna's model and combined the viscosity model with the Volume of Fluid(VOF) model by the User Defined Function(UDF) method. The results show that the surface temperature significantly affected the spreading behaviors of the silicone droplet since it determines the temperature and viscosity distribution inside the droplet. For surface temperature varied from 25 ℃ to 250 ℃, the final contact radius changed from ~2.95 mm to ~1.78 mm and the total spreading time changed from ~511 s to ~0.15 s. By further analyzing the viscosity evolution of the droplet, we found that the decreasing of the total spreading time was caused by the decrease of the viscosity under high surface temperature at initial spreading stage, while the reduction of the final contact radius was caused by the curing of the precursor film. This study supplies a strategy to tuning the spreading and curing behavior of silicone by imposing high surface temperature, which is of great importance to the electronic packaging. 相似文献
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A novel bio‐based phthalonitrile resin derived from catechin: synthesis and comparison of curing behavior with petroleum‐based counterpart
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Yu Qi Zhihuan Weng Jinyan Wang Shouhai Zhang Lishuai Zong Cheng Liu Xigao Jian 《Polymer International》2018,67(3):322-329
The development of bio‐based thermosetting resins with good thermal stability can potentially afford sustainable polymers as replacements for petroleum‐based polymers. We report a practical route to a novel catechin‐based phthalonitrile resin precursor (CA‐Ph), which contains free phenolic hydroxyl groups that result in ‘self‐curing’ at elevated temperatures to afford a thermostable polymer. Comparison of the performance of this CA‐Ph resin with that of a conventional petroleum‐based bisphenol A phthalonitrile resin (BPA‐Ph; containing 5 wt% of the curing agent 4,4′‐diaminodiphenylsulfone) revealed that CA‐Ph exhibits a lower melting point and curing temperature. Cured CA‐Ph resin retains 95% of its weight at 520 °C under a nitrogen atmosphere, which compares favorably with results obtained for BPA‐Ph resin that retains 95% of its weight at a lower temperature of 484 °C. Kinetic results indicated that the curing reactions of both CA‐Ph and BPA‐Ph systems follow an autocatalytic mechanism. These results suggest that catechin is a useful bio‐based feedstock for the preparation of self‐curing and thermally stable phthalonitrile resins for advanced technological applications. © 2017 Society of Chemical Industry 相似文献
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苎麻落麻纤维增强热固性树脂复合材料的制备及性能研究 总被引:8,自引:4,他引:8
本文介绍了落麻纤维、落麻热压毡、落麻无纺毡制备热固性树脂复合材料的工艺过程;比较了这三种复合材料的力学性能;结果表明,用无纺毡制备复合材料的方法可较大幅度提高纤维含量,能较好地解决落麻纤维在复合材料中的分散问题. 相似文献
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The Magazine House of EPA 《工程塑料应用》1995,(4)
根据国内有关工程塑料的文献,报道了1994年国内热塑性树脂及塑料、热固性树脂及塑料、成型加工技术的进展,以及工程塑料在国民经济各个领域中的研究开发和应用。 相似文献
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解释了膨胀聚苯乙烯泡沫板(EPS板)、石墨模塑聚苯乙烯泡沫塑料板(SEPS板)和热固性改性聚苯乙烯泡沫塑料板(热固性EPS板)的定义,对6个不同厂家生产的EPS板、SEPS板、热固性EPS板的主要物理性能进行了研究,得出了一些有实用价值的结论。 相似文献
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