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首页> 外文会议>Society of Plastics Engineers Annual Technical Conference 2005(ANTEC 2005) vol.6; 20050501-05; Boston,MA(US) >EVOLUTION OF PROPERTIES OF A THERMOSETTEMG EPOXY/AROMATIC AMINE SYSTEM WITH INCREASING CURE (CONVERSION): PHYSICAL AGING
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EVOLUTION OF PROPERTIES OF A THERMOSETTEMG EPOXY/AROMATIC AMINE SYSTEM WITH INCREASING CURE (CONVERSION): PHYSICAL AGING

机译：固化（转化率）提高的热固环氧树脂/芳香胺体系的性能演化：物理老化

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摘要

Isothermal physical aging below T_g of a high-T_g thermosetting difunctional epoxy/tetrafunctional aromatic amine system has been investigated at different aging temperatures (T_a) and chemical conversions (monitored by the glass transition temperature, T_g) using the TBA freely oscillating torsion pendulum technique. In the absence of chemical reaction during an isothermal aging process, the rate of isothermal physical aging passes through a minimum with increasing conversion. The minimum is related to the minimum in mechanical loss between the secondary relaxation in the glassy state (T_β) and the glass transition relaxation (T_g) [the temperatures of both of which increase with increasing conversion]. If isothermal aging rates for all conversions (beyond gelation) would have been measured directly from temperatures below T_Γ to above T_g, it is concluded that two maxima in isothermal aging rate would have been observed corresponding to the two relaxation processes. There exists a superposition in isothermal aging rate vs. T_g-T_a [by shifting horizontally (and vertically)], which implies that the aging rate is independent of the details of the changing chemical structure due to cure. Controlling mechanisms during physical aging are segmental mobility associated with the T_g region and more localized motion associated with the glassy-state relaxation, T_β.
机译：在T_g高热固性双官能环氧/四官能芳族胺体系的T_g以下等温物理老化已通过使用TBA自由振荡扭转摆技术在不同的老化温度（T_a）和化学转化率（由玻璃化转变温度T_g监测）下进行了研究。在等温老化过程中没有化学反应的情况下，等温物理老化的速率随着转化率的增加而达到最小值。该最小值与玻璃态的二次弛豫（T_β）和玻璃化转变弛豫（T_g）之间的机械损耗的最小值有关[两者的温度均随着转化率的增加而升高]。如果将直接从低于T_Γ到高于T_g的温度测量所有转化（超出凝胶化）的等温老化速率，则得出结论，将观察到与这两个松弛过程相对应的等温老化速率的两个最大值。 [通过水平（和垂直）移动]等温老化速率与T_g-T_a存在重叠，这表明老化速率与固化引起的化学结构变化的细节无关。物理老化过程中的控制机制是与T_g区域相关的分段运动以及与玻璃态松弛T_β相关的局部运动。

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