Haramina Tatjana, Pugar Daniel, Ivančević Darko, Smojver Ivica
Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, I. Lučića 5, 10 000 Zagreb, Croatia.
Polymers (Basel). 2021 Jan 5;13(1):165. doi: 10.3390/polym13010165.
The capability of poly(ethylene-co-methacrylic acid) (E/MAA) to self-heal is well known, however, its mechanical properties are weak. In this study, composites with single and double layers of unidirectional (UD) carbon fibers were prepared by compression molding. Even a low mass fraction of fibers substantially improved the polymer. The flexural and tensile properties were tested at 0°, 45° and 90° fibers direction and compared to those of the matrix. The mechanical properties in the 0° direction proved superior. Flexural properties depended on the reinforcement distance from the stress neutral plane. The tensile modulus in the 0° direction was 13 times greater despite only a 2.5% mass fraction of fibers. However, both tensile modulus and strength were observed to degrade in the 90° direction. Dynamic mechanical analysis showed the dependence of both structure and properties on the thermal history of E/MAA. Tensile tests after ballistic impact showed that the modulus of the self-healed E/MAA was not affected, yet the strength, yield point, and particularly the elongation at break were reduced. A composite with higher fiber content could be prepared by mixing milled E/MAA particles in fibers prior to compression.
聚（乙烯 - 共 - 甲基丙烯酸）（E/MAA）的自愈合能力是众所周知的，然而，其机械性能较弱。在本研究中，通过压缩成型制备了具有单层和双层单向（UD）碳纤维的复合材料。即使纤维的质量分数较低，也能显著改善聚合物性能。在纤维方向为0°、45°和90°时测试了弯曲和拉伸性能，并与基体的性能进行了比较。结果表明，在0°方向上的机械性能更优。弯曲性能取决于增强材料与应力中性平面的距离。尽管纤维质量分数仅为2.5%，但在0°方向上的拉伸模量却高出13倍。然而，在90°方向上，拉伸模量和强度均有所下降。动态力学分析表明，E/MAA的结构和性能均取决于其热历史。弹道冲击后的拉伸试验表明，自愈合后的E/MAA模量未受影响，但强度、屈服点，尤其是断裂伸长率有所降低。通过在压缩前将研磨后的E/MAA颗粒与纤维混合，可以制备纤维含量更高的复合材料。
