Gargiuli J F, Quino G, Board R, Griffith J C, Shaffer M S P, Trask R S, Hamerton I
Bristol Composites Institute, School of Civil, Aerospace, and Design Engineering, Faculty of Science and Engineering, University of Bristol, Queen's Building, University Walk, Bristol BS8 1TR, UK.
Department of Aeronautics, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
Polymers (Basel). 2023 Oct 8;15(19):4022. doi: 10.3390/polym15194022.
Four commercial high-performance aerospace aromatic epoxy matrices, CYCOM890, CYCOM977-2, PR520, and PRISM EP2400, were cured to a standardised 2 h, 180 °C cure cycle and evaluated in quasi-static uniaxial compression, as well as by dynamic scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The thermoplastic toughened CYCOM977-2 formulation displayed an overall increase in true axial stress values across the entire stress-strain curve relative to the baseline CYCOM890 sample. The particle-toughened PR520 sample exhibited an overall decrease in true axial stress values past the yield point of the material. The PRISM EP2400 resin, with combined toughening agents, led to true axial stress values across the entire plastic region of the stress-strain curve, which were in line with the stress values observed with the CYCOM890 material. Interestingly, for all formulations, the dilation angles (associated with the volume change during plastic deformation), recorded at 0.3 plastic strain, were close to 0°, with the variations reflecting the polymer structure. Compression data collected for this series of commercial epoxy resins are in broad agreement with a selection of model epoxy resins based on di- and tetra-functional monomers, cured with polyamines or dicarboxylic anhydrides. However, the fully formulated resins demonstrate a significantly higher compressive modulus than the model resins, albeit at the expense of yield stress.
四种商用高性能航空航天芳香族环氧基体CYCOM890、CYCOM977 - 2、PR520和PRISM EP2400，按照标准化的2小时、180°C固化周期进行固化，并通过准静态单轴压缩以及动态扫描量热法（DSC）和热重分析（TGA）进行评估。相对于基线CYCOM890样品，热塑性增韧的CYCOM977 - 2配方在整个应力 - 应变曲线上的真实轴向应力值总体有所增加。颗粒增韧的PR520样品在材料屈服点之后真实轴向应力值总体下降。具有复合增韧剂的PRISM EP2400树脂在应力 - 应变曲线的整个塑性区域产生的真实轴向应力值，与CYCOM890材料观察到的应力值一致。有趣的是，对于所有配方，在0.3塑性应变下记录的膨胀角（与塑性变形期间的体积变化相关）接近0°，其变化反映了聚合物结构。为这一系列商用环氧树脂收集的压缩数据与基于二官能和四官能单体、用多胺或二羧酸酐固化的一些模型环氧树脂大致相符。然而，完全配方化的树脂表现出比模型树脂显著更高的压缩模量，尽管是以牺牲屈服应力为代价。
