Zotti Aldobenedetto, Zuppolini Simona, Borriello Anna, Vinti Valeria, Trinchillo Luigi, Zarrelli Mauro
Institute for Polymers, Composites and Biomaterials, National Research Council of Italy, P.le Fermi, 1, 80055 Portici, NA, Italy.
Avio S.p.A., Via Leonida Bissolati, 76, 00187 Roma, RM, Italy.
Polymers (Basel). 2024 Feb 27;16(5):638. doi: 10.3390/polym16050638.
In the present work, the effects of carbon-based nanofillers (0.5 wt%), i.e., graphene nanoplatelets (GNPs), carbon nanofibers (CNFs), and carbon nanotubes (CNTs), on the cryogenic temperature (77 K) mechanical properties of carbon fiber reinforced polymers (CFRPs) were investigated. The study utilized an ex situ conditioning method for cryogenic tests. The nanofillers were mixed with the epoxy matrix by a solvent-free fluidized bed mixing technique (FBM), while unidirectional carbon fibers were impregnated with the resulting nanocomposites to manufacture CFRP samples. Optical microscopy was employed to analyze the dispersion of the carbon-based fillers within the matrix, revealing a homogeneous distribution in nanocomposites containing GNPs and CNFs. Fracture toughness tests confirmed the homogeneity of the GNP-loaded systems, showing an improvement in the stress intensity factor (KC) by 13.2% and 14.7% compared to the unmodified matrix at RT (25 °C) and 77 K, respectively; moreover, flexural tests demonstrated a general increase in flexural strength with the presence of carbon-based nanofillers at both temperature levels (RT and 77 K). Additionally, interlaminar shear strength (ILSS) tests were performed and analyzed using the same ex situ conditioning method.
在本研究中，研究了碳基纳米填料（0.5 wt%），即石墨烯纳米片（GNP）、碳纳米纤维（CNF）和碳纳米管（CNT）对碳纤维增强聚合物（CFRP）低温（77 K）力学性能的影响。该研究采用了一种用于低温测试的非原位处理方法。通过无溶剂流化床混合技术（FBM）将纳米填料与环氧基体混合，同时将单向碳纤维用所得纳米复合材料浸渍以制造CFRP样品。采用光学显微镜分析碳基填料在基体内的分散情况，发现在含有GNP和CNF的纳米复合材料中分布均匀。断裂韧性测试证实了含GNP体系的均匀性，与未改性基体相比，在室温（25°C）和77 K下，应力强度因子（KC）分别提高了13.2%和14.7%；此外，弯曲测试表明，在两个温度水平（室温与77 K）下，碳基纳米填料的存在都会使弯曲强度普遍提高。此外，采用相同的非原位处理方法进行并分析了层间剪切强度（ILSS）测试。
