Gavrilieva Anna A, Startsev Oleg V, Lebedev Mikhail P, Krotov Anatoly S, Kychkin Anatoly K, Lukachevskaya Irina G
Siberian Branch of the Russian Academy of Sciences V.P. Larionov Institute of Physical and Technical Problems of the North, 1 Oktyabrskaya Str., 677000 Yakutsk, Russia.
Siberian Branch of the Russian Academy of Sciences Federal Research Center «Yakut Scientific Center SB RAS», 2 Petrovskogo Str., 677000 Yakutsk, Russia.
Polymers (Basel). 2024 Sep 10;16(18):2550. doi: 10.3390/polym16182550.
The purpose of this study was to obtain information on the influence of the size factor on the climatic aging of circular fiber plastics produced by pultrusion. The kinetics of moisture transfer was obtained in humidification and drying modes at 60 °C in samples of epoxy basalt fiber reinforcement bars: after 28 months of exposure in the extremely cold climate of Yakutsk and 30 months of exposure in the moderately warm climate of Gelendzhik. It was shown that the 2D Langmuir model adequately describes the kinetics. The diffusion coefficients in the reinforcement direction for bars with diameters of 6, 8, 10, 16 and 20 mm turned out to be significantly higher than in the radial direction. To clarify the aging mechanism of the bars and the tensile, compressive and bending strength, the coefficient of linear thermal expansion and the glass transition temperature of the epoxy matrix of the bars with a diameter of 6, 8 and 10 mm after 51 months of exposure in Yakutsk and 54 months of exposure in Gelendzhik were measured. It was shown that after climatic exposure, the deformability of the bars decreased with increasing diameter of the bar; the glass transition temperature increased more significantly in the bar with a smaller diameter. In 6 mm diameter bars, the compressive and bending strength limits decreased by 10-25 % due to the plasticizing effect of moisture. With the same depth of moisture penetration into the volume of the samples, its effect on the strength of thin bars was significant, and for thick bars, it was insignificant. An increase in the glass transition temperature by 6 °C, associated with the additional curing of the polymer matrix, occurred in the surface layer of the epoxy basalt fiber reinforcement bars and was revealed in bars with a smaller diameter.
本研究的目的是获取尺寸因素对拉挤成型圆形纤维塑料气候老化影响的相关信息。在60°C的加湿和干燥模式下，获得了环氧玄武岩纤维增强棒材样品中的水分传输动力学数据：这些样品分别在雅库茨克的极寒气候中暴露28个月，以及在格连吉克的适度温暖气候中暴露30个月。结果表明，二维朗缪尔模型能够充分描述该动力学过程。直径为6、8、10、16和20毫米的棒材在增强方向上的扩散系数显著高于径向方向。为了阐明棒材的老化机制以及拉伸、压缩和弯曲强度，测量了直径为6、8和10毫米的棒材在雅库茨克暴露51个月和在格连吉克暴露54个月后，环氧基体的线性热膨胀系数和玻璃化转变温度。结果表明，经过气候暴露后，棒材的变形能力随着棒材直径的增加而降低；玻璃化转变温度在直径较小的棒材中升高更为显著。由于水分的增塑作用，直径6毫米的棒材的压缩和弯曲强度极限降低了10% - 25%。在样品体积中水分渗透深度相同的情况下，其对细棒材强度的影响显著，而对粗棒材的影响不显著。环氧玄武岩纤维增强棒材表层的玻璃化转变温度因聚合物基体的额外固化而升高了6°C，且在直径较小的棒材中更为明显。
