用差示扫描量热仪(DSC)研究了4,4′-二氨基二苯甲烷环氧树脂(TGDDM)/4,4′-二氨基二苯基砜(DDS)环氧树脂体系及其多壁碳纳米管复合物的固化行为。碳纳米管加入TGDDM/DDS体系后,起始固化反应速率增大,达到最大反应速率的时间减小,说明碳...用差示扫描量热仪(DSC)研究了4,4′-二氨基二苯甲烷环氧树脂(TGDDM)/4,4′-二氨基二苯基砜(DDS)环氧树脂体系及其多壁碳纳米管复合物的固化行为。碳纳米管加入TGDDM/DDS体系后,起始固化反应速率增大,达到最大反应速率的时间减小,说明碳纳米管对环氧树脂的固化反应有催化作用。和纯树脂相比,在固化反应初期碳纳米管复合物的活化能降低。在玻璃化现象出现以前,K am a l的固化动力学模型得到的结果与实验数据相当吻合。展开更多
The effect of an external electric field on the crystallization behavior of amorphous (Nd0.1Fe0.9)(3) B alloy was investigated. The crystallization product of Nd2Fe23B3 phase was obtained for this amorphous alloy anne...The effect of an external electric field on the crystallization behavior of amorphous (Nd0.1Fe0.9)(3) B alloy was investigated. The crystallization product of Nd2Fe23B3 phase was obtained for this amorphous alloy annealed at 923 K for 300 s in the presence of an external electric field of 300 kV .m(-1) (50 Hz); while the crystallization products are Nd1.1Fe4B4, alpha-Fe, and Fe3B phases under the same annealing condition except for free-electric field. On the other hand, the samples were annealed at 1023 K, which is higher than the decomposition temperature of metastable Nd2Fe23B3 phase, for 600 s. In the case of the presence of an external electric field, the metastable Nd2Fe23 B-3 phase, as a main phase, is still stayed in the sample. This fact suggests that the external electric field enhances the stabilization of the metastable Nd2Fe23B3 phase. The effect of the external electric field on the phase selection and stabilization was explained in terms of the specific conductance difference between the crystallization products.展开更多
文摘用差示扫描量热仪(DSC)研究了4,4′-二氨基二苯甲烷环氧树脂(TGDDM)/4,4′-二氨基二苯基砜(DDS)环氧树脂体系及其多壁碳纳米管复合物的固化行为。碳纳米管加入TGDDM/DDS体系后,起始固化反应速率增大,达到最大反应速率的时间减小,说明碳纳米管对环氧树脂的固化反应有催化作用。和纯树脂相比,在固化反应初期碳纳米管复合物的活化能降低。在玻璃化现象出现以前,K am a l的固化动力学模型得到的结果与实验数据相当吻合。
文摘The effect of an external electric field on the crystallization behavior of amorphous (Nd0.1Fe0.9)(3) B alloy was investigated. The crystallization product of Nd2Fe23B3 phase was obtained for this amorphous alloy annealed at 923 K for 300 s in the presence of an external electric field of 300 kV .m(-1) (50 Hz); while the crystallization products are Nd1.1Fe4B4, alpha-Fe, and Fe3B phases under the same annealing condition except for free-electric field. On the other hand, the samples were annealed at 1023 K, which is higher than the decomposition temperature of metastable Nd2Fe23B3 phase, for 600 s. In the case of the presence of an external electric field, the metastable Nd2Fe23 B-3 phase, as a main phase, is still stayed in the sample. This fact suggests that the external electric field enhances the stabilization of the metastable Nd2Fe23B3 phase. The effect of the external electric field on the phase selection and stabilization was explained in terms of the specific conductance difference between the crystallization products.
