Effect of aging on structure and stress relaxation of PP/SSFs composites

被引：0
|
作者：
Zhu Z. [1 ]
Shao B. [1 ]
Wang J. [1 ]
Shao Y. [1 ]
Chen J. [1 ]
Zhang M. [1 ]
机构：
[1] Faculty of Mechanical Engineering & Mechanics, Ningbo University, Ningbo, 315000, Zhejiang
来源：
Lixue Xuebao/Chinese Journal of Theoretical and Applied Mechanics | 2018年 / 50卷 / 03期
关键词：
Aging; Conductive composites; Crystallinity; SEM/EDS; Stress relaxation; XRD;
D O I：
10.6052/0459-1879-18-080
中图分类号：
学科分类号：
摘要：
Conductive polymer composites, with good flexibility, adjustable conductivity, easy forming and low production cost, can be used as functional material in many fields for its antistatic properties, electromagnetic shielding/microwave absorbing properties, and pressure/temperature sensitivity. However, in the process of processing, storage and use, due to comprehensive influence of many factors, aging will inevitably occur which will lead to deterioration of the properties. In this paper, PP/SSFs (stainless steel fibers) conductive composites were prepared by melt-blending and injection molding. The specimens were subjected to accelerated hygrothermal aging and UV aging. Stress relaxation curves, resistivity and crystallinity were experimentally measured. Micromorphology and elemental distribution of specimens before and after aging have been observed and dectected by scanning electron microscope (SEM) and energy spectrometer (EDS). The results show that the stress relaxation curves display three-stages in characteristics. And the stress reduces after hygrothermal aging due to the breaking and cross-linking of molecular chain caused by aging. The initial resistivity of PP/SSFs composites decreases with the increase of filler content, while it will increased with aging time. Due to the piezoresistive effect of the conductive polymer, the resistivity of the specimens decreases significantly with the increase of initial load, and then it tends to a stable value and fluctuation in a smaller range. The results of SEM/EDS analysis show that with the increase of aging time, the oxygen content on the specimens surface increases, and it will decreases with distance (depth) to the surface of specimen. XRD results show that the crystallinity of composites decreased with the increase of SSFs content and aging time. The present research will provide an experimental basis for the study of aging properties of conductive polymer composites. © 2018, Editorial Office of Chinese Journal of Theoretical and Applied Mechanics. All right reserved.
引用
收藏
页码：517 / 526
页数：9
相关论文
共 35 条
  • [1] Wang S., Chung D.D.L., Negative piezoresistivity in continuous carbon fiber epoxy-matrix composite, Journal of Materials Science, 42, 13, pp. 4987-4995, (2007)
  • [2] Qu S., Wong S.C., Piezoresistive behavior of polymer reinforced by expanded graphite, Composites Science & Technology, 67, 2, pp. 231-237, (2007)
  • [3] Zhou J., Song Y., Zheng Q., Viscoelastic resistance response of polymer based conductive composites, New Technology & New Products in China, 21, pp. 53-54, (2015)
  • [4] Liu H., Stress response and mechanism of flexible thermoplastic polyurethane conductive nanocomposites, (2017)
  • [5] Xu P., Wang X., Hu Y., Et al., The piezoresistive properties of allyl ionic liquid modified carbon black/silicone rubber composites, Polymeric Materials Science and Engineering, 33, 6, pp. 65-69, (2017)
  • [6] Suo Q., Preparation and properties of polybutene-based foamed material, (2016)
  • [7] Zuo Z., Xia Z., Nie J., Et al., Influence of carbon fiber filling on the piezoresistive effect and resistance creep behavior of conductive silicone rubber, Materials Review, 30, pp. 440-443, (2016)
  • [8] Wang P., Ding T., Conductivity and piezoresistivity of conductive carbon black filled polymer composite, Journal of Applied Polymer Science, 116, 4, pp. 2035-2039, (2010)
  • [9] Zhang Z., Gu X., Yang Y., Et al., Stress relaxation and creep behavior of polyethylene pipe special material (PE-XRT70), Journal of Sichuan University (Engineering Science), 49, 2, pp. 232-239, (2017)
  • [10] Zhang X., Yao Z., Zhang S., Et al., Analysis of the influence of stress relaxation on PET/carbon black/carbon fiber composites, Engineering Plastics Application, 45, 4, pp. 99-103, (2017)
1234