Article
Polymer Science
Seul-Yi Lee, Min-Joo Kang, Seong-Hwang Kim, Kyong Yop Rhee, Jong-Hoon Lee, Soo-Jin Park
Summary: The study found that the addition of PEI significantly enhances the thermal stability and mechanical properties of epoxy resins, and the formation of semi-interpenetrating polymer networks (semi-IPNs) helps improve flexural strength and fracture toughness.
Article
Chemistry, Multidisciplinary
Li-Cheng Jheng, Ting-Yu Chang, Chin-Ting Fan, Tsung-Han Hsieh, Feng-Ming Hsieh, Wan-Ju Huang
Summary: Amphiphilic comb-like random copolymers synthesized from PEGMMA and SMA can self-assemble into various well-defined nanostructures in epoxy thermosets, and can improve the toughness and fracture toughness of the epoxy.
Article
Polymer Science
Xunan Hou, Shuai Chen, J. Justin Koh, Junhua Kong, Yong-Wei Zhang, Jayven C. C. Yeo, Haiming Chen, Chaobin He
Summary: This study demonstrates that the entropy effect can control the phase structure and mechanical behaviors of polymer blends. For weakly interacting polymer pairs, the mixing entropy favors the formation of nanoscale cocontinuous structures, leading to superductile materials.
Article
Chemistry, Multidisciplinary
Emanuele Maccaferri, Jacopo Ortolani, Laura Mazzocchetti, Tiziana Benelli, Tommaso Maria Brugo, Andrea Zucchelli, Loris Giorgini
Summary: Delamination is a severe weakness in composite materials with a laminar structure. The use of electrospun polyethylene oxide (PEO) nanofibers as reinforcing layers in epoxy-based carbon fiber-reinforced polymer (CFRP) laminates shows significant improvement in interlaminar fracture toughness. The PEO-modified laminate demonstrates enhanced toughness under Mode I and Mode II loading, as well as good humidity resistance and maintenance of stiffness and glass transition temperature.
Article
Polymer Science
George Irven, Declan Carolan, Alexander Fergusson, John P. Dear
Summary: Epoxy foams with densities ranging from 180 to 500 kg/m3 were mechanically tested and a transition in fracture behavior at a critical density was observed. Lower density foams exhibited lower toughness and fracture energy, while higher density foams showed higher values. Stress-intensity factor increased monotonically with density. The distribution of cell size varied between lower and higher density foams. This study suggests the potential use of higher density foams in composite sandwich structures to achieve increased fracture energy.
Article
Polymer Science
Matthew D. Eaton, L. Catherine Brinson, Kenneth R. Shull
Summary: The study investigated the effect of nanoscale heterogeneity on the mode I fracture toughness of model epoxy networks, with results showing that high toughness is achieved in heterogeneous networks.
Article
Materials Science, Multidisciplinary
Majid Mehrabi-Mazidi, Mir Karim Razavi-Aghjeh
Summary: The study investigates the impact of microstructural development at different PA6:EPDM-g-MA weight ratios on the macroscopic mechanical and fracture characteristics of highly-toughened blends. It is found that an increase in EPDM-g-MA:PA6 ratio leads to the formation of agglomerated core-shell domains. The fracture works reveal a sole dependence on rubbery fraction, while impact data show a significant synergistic toughening effect of dispersed composite domains in ternary blends compared with binary blends.
MACROMOLECULAR MATERIALS AND ENGINEERING
(2021)
Article
Engineering, Manufacturing
Melike Kilicoglu, Erhan Bat, Guengoer Guenduez, Mustafa Utku Yildirim, Kamil Urgun, Bora Mavis
Summary: Interleaving fiber reinforced layered composites with thermoplastic veils can activate different toughening mechanisms. The blend composition plays a crucial role in activating these mechanisms.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2022)
Article
Engineering, Multidisciplinary
George Irven, Declan Carolan, Alexander Fergusson, John P. Dear
Summary: Low density aramid and carbon fibre-reinforced epoxy foam was synthesized to improve mechanical properties, especially fracture performance. Fracture energy, compressive strength, and density of the foam were measured. The study investigated the influence of fibre type, loading, and length. The addition of fibres improved mechanical performance, with a significant increase in fracture energy and face-sheet bond propagation fracture toughness.
COMPOSITES PART B-ENGINEERING
(2023)
Article
Materials Science, Composites
Kanokporn Tangthana-umrung, Matthieu Gresil
Summary: Healable and recyclable fibre reinforced vitrimer composites have been developed, which exhibit superior mechanical and interlaminar fracture properties. The findings reveal the potential for further development of vitrimer CFRP composites for advanced applications.
COMPOSITES COMMUNICATIONS
(2022)
Article
Nanoscience & Nanotechnology
Ujala Farooq, Ekaterina Sakarinen, Julie Teuwen, Rene Alderliesten, Clemens Dransfeld
Summary: In this study, the synergistic effects of toughening phases on multiple scales in epoxies were investigated by adding layered poly-(ether imide) (PEI) structures and gradient morphologies. The results show that the fracture toughness of the modified epoxy is mainly determined by the thickness of the PEI layer. When the layer thickness exceeds a certain value, the fracture toughness of the dual scale morphology exceeds the performance of bulk PEI and pure epoxy. The microscale interphase morphology also affects the fracture toughness of the modified epoxy.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Engineering, Mechanical
K. Mishra, L. Brassart, A. Singh
Summary: The fracture behavior of highly cross-linked epoxy resin under different crack tip strain rates was studied. The plane strain fracture toughness initially decreases with increasing strain rate and stabilizes after reaching a certain strain rate. A fracture process zone forms ahead of the sharp pre-crack in all specimens, and the micro mechanism of fracture is governed by crazes. In-situ testing in a scanning electron microscope confirmed the existence of crazes. The size of the craze openings varies with strain rate, with larger openings at lower strain rates and smaller openings at higher strain rates.
ENGINEERING FAILURE ANALYSIS
(2022)
Article
Materials Science, Multidisciplinary
Vincent Pang, Zachary J. Thompson, Guy D. Joly, Lorraine F. Francis, Frank S. Bates
Summary: The study evaluated the effects of nanoscale silica particle additives on the tensile properties of modified epoxies, showing an increase in modulus and toughness. Combining BCP and nanosilica additives resulted in a synergistic effect, enhancing the toughness of the epoxy beyond that obtained with individually modified formulations.
ACS APPLIED POLYMER MATERIALS
(2021)
Article
Engineering, Manufacturing
Kang Yang, Zihong Wu, Changgeng Zhou, Siyu Cai, Zhentao Wu, Wenhan Tian, Sujun Wu, Robert O. Ritchie, Juan Guan
Summary: Natural silk fibre can enhance the toughness and impact strength of composites when reinforced in polymer matrices, with the epoxy resin derived from bisphenol-A epoxy and aliphatic diamine precursors showing the highest performance in terms of tensile breaking energy and impact strength. The toughening mechanisms in these composites are mainly crack propagation and fiber pull-out, regardless of whether the matrix is brittle or ductile. The study aims to provide guidelines for designing matrices in silk fibre-reinforced plastics with optimal toughness by identifying key toughening mechanisms.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2022)
Article
Engineering, Manufacturing
Jun Cong Long, Hang Zhan, Guang Wu, Yu Zhang, Jian Nong Wang
Summary: A facile and effective method was proposed for preparing high-strength CNT/EP composite films, achieving a tensile strength of 2.5 GPa, which is about 5 times that of the raw CNT film. This approach may offer an effective strategy for the preparation of high-performance CNT composite materials.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2021)
