Aldosari Salem Mohammed, Khan Muhammad A, Rahatekar Sameer
Enhanced Composite and Structures Centre School of Aerospace, Transport, and Manufacturing, Cranfield University, Cranfield MK43 0AL, UK.
National Centre for Aviation Technology, King Abdulaziz City for Science and Technology (Kacst), Riyadh 11442, Saudi Arabia.
Polymers (Basel). 2021 Apr 29;13(9):1445. doi: 10.3390/polym13091445.
The advantage of mesophase pitch-based carbon fibres is their high modulus, but pitch-based carbon fibres and precursors are very brittle. This paper reports the development of a unique manufacturing method using a blend of pitch and linear low-density polyethylene (LLDPE) from which it is possible to obtain precursors that are less brittle than neat pitch fibres. This study reports on the structure and properties of pitch and LLDPE blend precursors with LLDPE content ranging from 5 wt% to 20 wt%. Fibre microstructure was determined using scanning electron microscopy (SEM), which showed a two-phase region having distinct pitch fibre and LLDPE regions. Tensile testing of neat pitch fibres showed low strain to failure (brittle), but as the percentage of LLDPE was increased, the strain to failure and tensile strength both increased by a factor of more than 7. DSC characterisation of the melting/crystallization behaviour of LLDPE showed melting occurred around 120 °C to 124 °C, with crystallization between 99 °C and 103 °C. TGA measurements showed that for 5 wt%, 10 wt% LLDPE thermal stability was excellent to 800 °C. Blend pitch/LLDPE carbon fibres showed reduced brittleness combined with excellent thermal stability, and thus are a candidate as a potential precursor for pitch-based carbon fibre manufacturing.
中间相沥青基碳纤维的优点是其高模量，但沥青基碳纤维及其前驱体非常脆。本文报道了一种独特制造方法的开发，该方法使用沥青和线性低密度聚乙烯（LLDPE）的混合物，由此能够获得比纯沥青纤维脆性更小的前驱体。本研究报道了LLDPE含量在5 wt%至20 wt%范围内的沥青与LLDPE共混前驱体的结构和性能。使用扫描电子显微镜（SEM）测定纤维微观结构，结果显示存在具有明显沥青纤维和LLDPE区域的两相区。纯沥青纤维的拉伸测试表明其断裂应变较低（脆性大），但随着LLDPE百分比的增加，断裂应变和拉伸强度均增加了7倍以上。LLDPE熔融/结晶行为的DSC表征显示，其熔融发生在120℃至124℃左右，结晶发生在99℃至103℃之间。热重分析（TGA）测量表明，对于5 wt%、10 wt%的LLDPE，其热稳定性在800℃时非常优异。共混沥青/LLDPE碳纤维显示出脆性降低且热稳定性优异，因此是沥青基碳纤维制造潜在前驱体的候选材料。
