Preparation and Performance of Self-Healing Epoxy Composites by Microcapsulated Approach

2014 ◽  
Vol 636 ◽  
pp. 73-77 ◽  
Author(s):  
Xin Hua Yuan ◽  
Qiu Su ◽  
Li Yin Han ◽  
Qian Zhang ◽  
Yan Qiu Chen ◽  
...  
Keyword(s):  
Impact Strength ◽  
Epoxy Matrix ◽  
The Self ◽  
Epoxy Composites ◽  
Fracture Plane ◽  
Crack Plane ◽  
Curing Agent ◽  
Self Healing ◽  
Healing Agent ◽  
The Impact

Microencapsulated E-51 epoxy resin healing agent and phthalic anhydride latent curing agent were incorporated into E-44 epoxy matrix to prepare self-healing epoxy composites. When cracks were initiated or propagated in the composites, the microcapsules would be damaged and the healing agent released. As a result, the crack plane was healed through curing reaction of the released epoxy latent curing agent. In the paper, PUF/E-51 microcapsules were prepared by in-situ polymerization. The mechanical properties of the epoxy composites filled with the self-healing system were evaluated. The impact strength and self-healing efficiency of the composites are measured using a Charpy Impact Tester. Both the virgin and healed impact strength depends strongly on the concentration of microcapsules added into the epoxy matrix. Fracture of the neat epoxy is brittle, exhibiting a mirror fracture surface. Addition of PUF/E-51 microcapsules decreases the impact strength and induces a change in the fracture plane morphology to hackle markings. In the case of 8.0 wt% microcapsules and 3.0 wt% latent hardener, the self-healing epoxy exhibited 81.5% recovery of its original fracture toughness.

scholarly journals Evaluation of Dispersion Methods and Mechanical Behaviour of Glass Fibre Composites with Embedded Self-Healing Systems

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1642
Author(s):  
Ionut Sebastian Vintila ◽  
Sorin Draghici ◽  
Horia Alexandru Petrescu ◽  
Alexandru Paraschiv ◽  
Mihaela Raluca Condruz ◽  
...  
Keyword(s):  
Impact Strength ◽  
Thermal Cycling ◽  
Glass Fibre ◽  
Mechanical Behaviour ◽  
Epoxy Matrix ◽  
Impact Testing ◽  
Self Healing ◽  
Dispersion Method ◽  
Fibre Composites ◽  
The Impact

The present paper is focused on evaluating the most suitable dispersion method in the epoxy matrix of two self-healing systems containing dicyclopentadiene (DCPD) and 5-ethylidene-2-norbornene (ENB) monomers encapsulated in a urea-formaldehyde (UF) shell, prior to integration, fabrication and impact testing of specimens. Both microstructural analysis and three-point bending tests were performed to evaluate and assess the optimum dispersion method. It was found that ultrasonication damages the microcapsules of both healing systems, thus magnetic stirring was used for the dispersion of both healing systems in the epoxy matrix. Using magnetic dispersion, 5%, 7%, 10%, 12% and 15% volumes of microcapsules were embedded in glass fibre composites. Some of the samples were subjected to thermal cycling between −20 °C and +100 °C for 8 h, to evaluate the behaviour of both healing systems after temperature variation. Impact test results showed that the mechanical behaviour decreases with increasing microcapsule volume, while for specimens subjected to thermal cycling, the impact strength increases with microcapsule volume up to 10%, after which a severe drop in impact strength follows. Retesting after 48 h shows a major drop in mechanical properties in specimens containing 15% MUF-ENB microcapsules, up to total penetration of the specimen.

scholarly journals Influence of Morphology on the Healing Mechanism of PCL/Epoxy Blends

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1941 ◽  
Author(s):  
Alberto Jiménez-Suárez ◽  
Gilberto Del Rosario ◽  
Xoan Xosé Sánchez-Romate ◽  
Silvia González Prolongo
Keyword(s):  
Epoxy Matrix ◽  
Surface Damage ◽  
The Self ◽  
Maximum Efficiency ◽  
Initial Surface ◽  
Self Healing ◽  
Blend Morphology ◽  
Healing Efficiency ◽  
Healing Agent ◽  
Epoxy Blends

Polycaprolactone (PCL) is being researched as a self-healing agent blended with epoxy resins by several reasons: low melting point, differential expansive bleeding (DBE) of PCL, and reaction induced phase separation (RIPS) of PCL/epoxy blends. In this work, PCL/epoxy blends were prepared with different PCL ratios and two different epoxy networks, cured with aliphatic and aromatic amine hardeners. The curing kinetic affects to the blend morphology, varying its critical composition. The self-healing behavior is strongly affected by the blend morphology, reaching the maximum efficiency for co-continuous phases. Blends with dispersed PCL phase into epoxy matrix can also show high self-healing efficiency because of the low PCL domains that act as reservoir of self-healing agent. In this last case, it was confirmed that the most efficient self-healable blends are one whose area occupied by PCL phase is the largest. These blends remain the good thermal and mechanical behavior of epoxy matrix, in contrast to the worsened properties of blends with bicontinuous morphology. In this work, the self-healing mechanism of blends is studied in depth by scanning electron microscopy. Furthermore, the influence of the geometry of the initial surface damage is also evaluated, affecting to the measurement of self-healing efficiency.

A Self-Repair Mode for Capillary Reinforced Polymer Composite

2013 ◽  
Vol 575-576 ◽  
pp. 147-150
Author(s):  
Xin Hua Yuan ◽  
Ji Ye Wu ◽  
Yong Qiang Liu ◽  
Jun Xia Mao ◽  
Xue Tao Ou ◽  
...  
Keyword(s):  
Impact Damage ◽  
The Self ◽  
Self Healing ◽  
Reinforced Polymer ◽  
Flexural Testing ◽  
Reinforced Plastic ◽  
Crack Morphology ◽  
Healing Agent ◽  
Self Repair ◽  
The Impact

The paper describes a novel capillary reinforced plastic which can self-repair the impact damage in polymer composites through employing a bio-mimetic approach. A epoxy resin E-51 and harder WSR706# was used as the healing agent, the two components being filled in to different directions (0°and 90° fibers). Impact test and tensile test were used as a measure of the self-healing effectiveness. The results of flexural testing have shown that strength lost after impact damage can be restored by the self-healing effect with healing agent stored in capillaries, and a significant fraction (about 79%) of lost mechanical strength is restored by this effect. At the same time, the paper also studied the morphology of fracture surface of no embedded and capillaries embedded sample. And micrographs of crack morphology which has been healed have been observed.

Wear Resistance of Polymers With Encapsulated Epoxy-Amine Self-Healing Chemistry

2015 ◽  
Vol 82 (5) ◽  
Author(s):  
Nay Win Khun ◽  
He Zhang ◽  
Jinglei Yang
Keyword(s):  
Epoxy Resin ◽  
Epoxy Matrix ◽  
In Situ Polymerization ◽  
Wear Test ◽  
Epoxy Composites ◽  
Self Healing ◽  
Matrix Composites ◽  
Water Emulsion ◽  
Healing Agent ◽  
Oil In Water Emulsion

In this study, epoxy resin was microencapsulated through in situ polymerization in an oil-in-water emulsion, and amine was loaded into etched glass bubbles (GBs) as a curing agent for the microencapsulated epoxy resin. The purpose was to develop a two-component-self-healing system. The two healing agent carriers were co-incorporated in the epoxy matrix to form novel epoxy composites for tribological applications. The tribological results clearly showed that an increase in healing agent carrier content significantly decreased the friction and wear of the epoxy composites tested against a 6 mm steel ball under different normal loads. This was due to the self-lubricating and self-healing of the composites with released core liquids via the rupture of healing agent carriers during the wear test. It could be concluded that the co-incorporation of two healing agent carriers was a potential way to achieve a significant improvement in the tribological properties of epoxy matrix composites.

scholarly journals The Effect of Superabsorbent Polymers on the Microstructure and Self-Healing Properties of Cementitious-Based Composite Materials

2021 ◽  
Vol 11 (2) ◽  
pp. 700
Author(s):  
Irene A. Kanellopoulou ◽  
Ioannis A. Kartsonakis ◽  
Costas A. Charitidis
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Hybrid Structure ◽  
The Self ◽  
Self Healing ◽  
Cementitious Composite ◽  
Superabsorbent Polymers ◽  
Porosity Reduction ◽  
Environment Control ◽  
The Impact

Cementitious structures have prevailed worldwide and are expected to exhibit further growth in the future. Nevertheless, cement cracking is an issue that needs to be addressed in order to enhance structure durability and sustainability especially when exposed to aggressive environments. The purpose of this work was to examine the impact of the Superabsorbent Polymers (SAPs) incorporation into cementitious composite materials (mortars) with respect to their structure (hybrid structure consisting of organic core—inorganic shell) and evaluate the microstructure and self-healing properties of the obtained mortars. The applied SAPs were tailored to maintain their functionality in the cementitious environment. Control and mortar/SAPs specimens with two different SAPs concentrations (1 and 2% bwoc) were molded and their mechanical properties were determined according to EN 196-1, while their microstructure and self-healing behavior were evaluated via microCT. Compressive strength, a key property for mortars, which often degrades with SAPs incorporation, in this work, practically remained intact for all specimens. This is coherent with the porosity reduction and the narrower range of pore size distribution for the mortar/SAPs specimens as determined via microCT. Moreover, the self-healing behavior of mortar-SAPs specimens was enhanced up to 60% compared to control specimens. Conclusively, the overall SAPs functionality in cementitious-based materials was optimized.

scholarly journals Influence of layering pattern of modified kenaf fiber on thermomechanical properties of epoxy composites

2019 ◽  
Vol 36 (1) ◽  
pp. 47-62
Author(s):  
AR Mohammed ◽  
MS Nurul Atiqah ◽  
Deepu A Gopakumar ◽  
MR Fazita ◽  
Samsul Rizal ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Modification ◽  
Epoxy Matrix ◽  
Epoxy Composites ◽  
Woven Composites ◽  
Fiber Reinforced ◽  
Kenaf Fiber ◽  
Kenaf Fibers ◽  
The Impact ◽  
Woven Kenaf

Natural fiber-reinforced composites gained considerable interest in the scientific community due to their eco-friendly nature, cost-effective, and excellent mechanical properties. Here, we reported a chemical modification of kenaf fiber using propionic anhydride to enhance the compatibility with the epoxy matrix. The incorporation of the modified woven and nonwoven kenaf fibers into the epoxy matrix resulted in the improvement of the thermal and mechanical properties of the composite. The thermal stability of the epoxy composites was enhanced from 403°C to 677°C by incorporating modified woven kenaf fibers into the epoxy matrix. The modified and unmodified woven kenaf fiber-reinforced epoxy composites had a tensile strength of 64.11 and 58.82 MPa, respectively. The modified woven composites had highest flexural strength, which was 89.4 MPa, whereas, for unmodified composites, it was 86.8 MPa. The modified woven fiber-reinforced epoxy composites showed the highest value of flexural modulus, which was 6.0 GPa compared to unmodified woven composites (5.51 GPa). The impact strength of the epoxy composites was enhanced to 9.43 kJ m−2 by the incarnation of modified woven kenaf fibers into epoxy matrix. This study will be an effective platform to design the chemical modification strategy on natural fibers for enhancing the compatibility toward the hydrophobic polymer matrices.

Effects of the Self-Healing Microcapsules on the Impact Property of Polymer Composite Gear

2011 ◽  
Vol 66-68 ◽  
pp. 683-687 ◽  
Author(s):  
Li Zhang ◽  
Yan Jue Gong ◽  
Shuo Zhang
Keyword(s):  
Glass Fiber ◽  
Polymer Composite ◽  
The Self ◽  
Impact Property ◽  
Self Healing ◽  
Fiber Reinforced ◽  
Mechanical Impact ◽  
Glass Fiber Reinforced ◽  
The Impact

By designing the different formulations of the composites and adopting optimized technology including extrusion and molding, the effects of the Micro-capsules on the properties of nylon composites are analyzed by the impact property test. The mechanical impact property of the glass fiber reinforced nylon composites is influenced little if the content of the self-healing microcapsules added is less than 3.5%, and the technology of self-healing microcapsules used in the polymer composite gear is feasible.

scholarly journals Characterization of Hybrid Oil Palm Empty Fruit Bunch/Woven Kenaf Fabric-Reinforced Epoxy Composites

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2052
Author(s):  
Farah Hanan ◽  
Mohammad Jawaid ◽  
Md Tahir Paridah ◽  
Jesuarockiam Naveen
Keyword(s):  
Impact Strength ◽  
Oil Palm ◽  
Failure Modes ◽  
Fiber Content ◽  
Epoxy Composites ◽  
Void Content ◽  
Empty Fruit Bunch ◽  
Kenaf Fiber ◽  
The Impact ◽  
Woven Kenaf

In this research, the physical, mechanical and morphological properties of oil palm empty fruit bunch (EFB) mat/woven kenaf fabric-reinforced epoxy composites have been investigated. The oil palm EFB/woven kenaf fabrics were varied, with weight ratios of 50/0 (T1), 35/15 (T2), 25/25 (T3), 15/35 (T4) and 0/50 (T5). The composites were fabricated using a simple hand lay-up technique followed by hot pressing. The result obtained shows that an increase in kenaf fiber content exhibited higher tensile and flexural properties. On the other hand, the opposite trend was observed in the impact strength of hybrid composites, where an increase in kenaf fiber content reduced the impact strength. This can be corroborated with the physical properties analysis, where a higher void content, water absorption and thickness swelling were observed for pure oil palm EFB (T1) composites compared to other samples. The scanning electron microscopy analysis results clearly show the different failure modes of the tensile fractured samples. Statistical analysis was performed using one-way ANOVA and shows significant differences between the obtained results.

Advanced Fiber Reinforced Self-Healing Ceramics for Middle Range Temperature

2019 ◽  
Vol 810 ◽  
pp. 119-124
Author(s):  
Wataru Nakao ◽  
Taira Hayakawa ◽  
Tesuro Yanaseko ◽  
Shingo Ozaki
Keyword(s):  
Low Temperature ◽  
Turbine Blade ◽  
The Self ◽  
Self Healing ◽  
Fiber Reinforced ◽  
Low Pressure Turbine ◽  
Middle Range ◽  
The Matrix ◽  
Healing Agent ◽  
Technical Issues

The availability of TiC healing agent has been evaluated in low temperature self-healing behavior of Al2O3 based self-healing ceramics. For this purpose, some technical issues to actualize the advanced fiber-reinforced self-healing ceramics containing TiC based interlayer as healing agent were discussed. Especially, the mechanical matching between the matrix and the interlayer was focused. Moreover, the self-healing behavior of the advanced shFRC containing the optimized TiC based healing agent was investigated. As a result, 30 vol% TiC-70 vol% Al2O3 interlayer was confirmed to be the optimized healing agent in the self-healing ceramics, and the self-healing ceramics was found to enable to attain the perfect healing at 600°C within 10 min. And we succeeded in prototype production of fiber-reinforced self-healing ceramics for low pressure turbine blade.

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