Multi-Mode Self-Healing in Composite Materials Using Novel Chemistry

2011 ◽  
Author(s):  
Ian Bond ◽  
Tim Coope ◽  
Richard Trask ◽  
Greg McCombe ◽  
Duncan Wass ◽  
...  
Keyword(s):  
Composite Materials ◽  
Epoxy Resin ◽  
Lewis Acid ◽  
Self Healing ◽  
Test Configuration ◽  
Frp Composite ◽  
Study Results ◽  
Healing Agent ◽  
Fibre Reinforced Polymer ◽  
Healing Temperature

A novel Lewis acid-catalysed self-healing system is investigated for implementation in epoxy-based fibre reinforced polymer (FRP) composite materials. The catalyst, scandium(III) triflate, is selected using a qualitative approach and subsequently embedded with pre-synthesised epoxy-solvent loaded microcapsules, into an epoxy resin. Healing is initiated when microcapsules are ruptured at the onset of crack propagation. The epoxy monomer healing agent contained within, actively undergoes ring-opening polymerisation (ROP) on contact with the locally placed catalyst, forming a new polymer to bridge the two fractured crack surfaces. Self-healing performance is quantified using tapered double cantilever beam (TDCB) epoxy resin test specimens and the effects of microcapsule loading, microcapsule content and healing temperature are all independently considered. As an initial proof of concept study, results show that a material recovery value of greater than 80% fracture strength is achieved for this novel Lewis acid-catalysed self-healing epoxy resin. The same self-healing agent system was subsequently demonstrated in a larger scale FRP component by incorporating both a microcapsule and hollow glass fibre (HGF) delivery system within an FRP laminate using a End-Notched Flexure (ENF) test configuration.

Self-Healing Fiber-Reinforced Polymer Composites

MRS Bulletin ◽  
2008 ◽  
Vol 33 (8) ◽  
pp. 770-774 ◽  
Author(s):  
Ian P. Bond ◽  
Richard S. Trask ◽  
Hugo R. Williams
Keyword(s):  
Composite Materials ◽  
High Performance ◽  
Fiber Reinforced Polymer ◽  
Self Healing ◽  
Fiber Reinforced ◽  
Internal Damage ◽  
Frp Composite ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Weight Penalty

AbstractSelf-healing is receiving an increasing amount of interest worldwide as a method to address damage in materials. In particular, for advanced high-performance fiber-reinforced polymer (FRP) composite materials, self-healing offers an alternative to employing conservative damage-tolerant designs and a mechanism for ameliorating inaccessible and invidious internal damage within a structure. This article considers in some detail the various self-healing technologies currently being developed for FRP composite materials. Key constraints for incorporating such a function in FRPs are that it not be detrimental to inherent mechanical properties and that it not impose a severe weight penalty.

scholarly journals Preparation and Characterization of Nano-CaCO3/Ceresine Wax Composite Shell Microcapsules Containing E-44 Epoxy Resin for Self-Healing of Cement-Based Materials

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 197
Author(s):  
Wei Du ◽  
Erwang Li ◽  
Runsheng Lin
Keyword(s):  
Epoxy Resin ◽  
Recovery Rate ◽  
Composite Shell ◽  
Chloride Ion ◽  
Self Healing ◽  
The Core ◽  
Core Content ◽  
Cement Based Materials ◽  
Healing Agent ◽  
Melt Condensation

As an intelligent material, microcapsules can efficiently self-heal internal microcracks and microdefects formed in cement-based materials during service and improve their durability. In this paper, microcapsules of nano-CaCO3/ceresine wax composite shell encapsulated with E-44 epoxy resin were prepared via the melt condensation method. The core content, compactness, particle size distribution, morphologies, chemical structure and micromechanical properties of microcapsules were characterized. The results showed that the encapsulation ability, mechanical properties and compactness of microcapsules were further improved by adding nano-CaCO3 to ceresine wax. The core content, elastic modulus, hardness and weight loss rate (60 days) of nano-CaCO3/ceresine wax composite shell microcapsules (WM2) were 80.6%, 2.02 GPA, 72.54 MPa and 1.6%, respectively. SEM showed that WM2 was regularly spherical with a rough surface and sufficient space inside the microcapsules to store the healing agent. The incorporation of WM2 to mortar can greatly improve the self-healing ability of mortar after pre-damage. After 14 days of self-healing, the compressive strength recovery rate, proportion of harmful pores and chloride ion diffusion coefficient recovery rate increased to 90.1%, 45.54% and 79.8%, respectively. In addition, WM2 also has good self-healing ability for mortar surface cracks, and cracks with initial width of less than 0.35 mm on the mortar surface can completely self-heal within 3 days.

scholarly journals Preparation and Characterization of Microcrystalline Wax/Epoxy Resin Microcapsules for Self-Healing of Cementitious Materials

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1725
Author(s):  
Wei Du ◽  
Quantao Liu ◽  
Runsheng Lin ◽  
Xin Su
Keyword(s):  
Epoxy Resin ◽  
Size Distribution ◽  
Weight Ratio ◽  
Cementitious Materials ◽  
Self Healing ◽  
Surface Cracks ◽  
Preparation Temperature ◽  
Core Content ◽  
Healing Agent

Self-healing of cracks in cementitious materials using healing agents encapsulated in microcapsules is an intelligent and effective method. In this study, microcapsules were prepared by the melt–dispersion–condensation method using microcrystalline wax as the shell and E-51 epoxy resin as the healing agent. The effects of preparation process parameters and microcrystalline wax/E-51 epoxy resin weight ratio on the core content, particle size distribution, thermal properties, morphology, and chemical composition of microcapsules were investigated. The results indicated that the optimal parameters of the microcapsule were microcrystalline wax/E-51 epoxy resin weight ratio of 1:1.2, stirring speed of 900 rpm, and preparation temperature of 105 °C. The effects of microcapsules on pore size distribution, pore structure, mechanical properties, permeability, and ultrasonic amplitude of mortar were determined, and the self-healing ability of mortar with different contents of microcapsules was evaluated. The optimal content of microcapsules in mortars was 4% of the cement weight, and the surface cracks of mortar containing microcapsules with an initial width of 0.28 mm were self-healed within three days, indicating that microcapsules have excellent self-healing ability for cementitious materials.

scholarly journals Preparation and Characterization of Microencapsulated Ethylenediamine with Epoxy Resin for Self-healing Composites

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Liye Yuan ◽  
Tongqing Sun ◽  
Honglin Hu ◽  
Shuxia Yuan ◽  
Yu Yang ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Interfacial Polymerization ◽  
Silicone Oil ◽  
Optical Microscope ◽  
Self Healing ◽  
Scanning Calorimetry ◽  
Oil Emulsion ◽  
Factors Affecting ◽  
Healing Agent ◽  
Water In Oil Emulsion

AbstractHealing agent microcapsules have been used to realize self-healing for polymeric composites. In this work a novel kind of microcapsules encapsulating ethylenediamine (EDA) with epoxy resin as shell material were prepared by interfacial polymerization technology. The oil phase was epoxy resin prepolymer and carbon tetrachloride, and the water phase was EDA and deionized water. Under the action of emulsifier, a stable water-in-oil emulsion was formed. Then the emulsion was added to dimethyl silicone oil, stirred and dispersed, to prepare microcapsules. In addition, the factors affecting the preparation of microcapsules were studied. In this study, Fourier transform infrared(FTIR) was carried out to demonstrate the chemical structure of ethylenediamine microcapsules. Optical microscope(OM) and scanning electron microscope(SEM) were used to observe the morphology of microcapsules. Thermogravimetric analysis and differential scanning calorimetry were done to investigate the thermal properties of microcapsules. Permeability experiment and isothermal aging test were executed to verify the environment resistance of microcapsules. Results showed that EDA was successfully coated in epoxy resin and the microcapsule size was in the range of 50~630 μm. The synthesized microcapsules were thermally stable below 75 °C and perfect permeability resistance to ethanol solvent.

Characterisation of Dicyclopentadiene Filled Microcapsules for Self-Healing Composite Materials

2015 ◽  
Vol 766-767 ◽  
pp. 3-7 ◽  
Author(s):  
J. Lilly Mercy ◽  
S. Prakash ◽  
Katta Sai Sandeep ◽  
Dasari Sai Praveen
Keyword(s):  
Particle Size ◽  
Composite Materials ◽  
Surface Morphology ◽  
Chemical Constituents ◽  
Urea Formaldehyde ◽  
Agitation Rate ◽  
Self Healing ◽  
Healing Agent ◽  
Different Diameters ◽  
Monomer Form

Self-healing composite materials possess healing agent which fills up the crack when ruptured and heals the crack by becoming a tough polymer when stimulated by a catalyst. Dicyclopentadiene (DCPD) in its monomer form is microencapsulated in the shell of Urea Formaldehyde (UF) under different agitation rates to acquire microcapsules of different diameters. The distribution of particle size, surface morphology and the presence of various chemical constituents in the microcapsules were analysed using optical microscopy, SEM and EDAX respectively. An agitation rate of 300 rpm, yielded capsules of diameters ranging from 800μm to 1700μm and at 900rpm the diameters were less than 300μm. Spherical shaped free flowing microcapsules were obtained through insitu polymerisation of dicyclopentadiene in Urea Formaldehyde.

scholarly journals Early Age Strength Healing Effect of Cementitious Composite Incorporated Self-Healing Microcapsule

2021 ◽  
pp. X
Author(s):  
Xingang WANG ◽  
Xingjing WANG ◽  
Yuhao XIE ◽  
Wei XU
Keyword(s):  
Epoxy Resin ◽  
Cement Paste ◽  
Influence Factors ◽  
Core Material ◽  
Early Age ◽  
Self Healing ◽  
Cementitious Composite ◽  
Healing Effect ◽  
Good Shape ◽  
Healing Temperature

Received 27 February 2019; accepted 02 September 2019 This paper aims to explore early age strength healing effect of cementitious composite incorporated self-healing microcapsule and curing activity of self-healing microcapsule. Particle characteristic of the microcapsule and micromorphology of cement paste incorporated the microcapsule were characterized by SEM. Curing activity of the microcapsule was analyzed by macroscopic solidification test, DSC and TGA. The influence factors of early age strength healing ratio in cementitious composite incorporated self-healing microcapsule were studied. The results showed that epoxy resin microcapsule had favorable micromorphology. Epoxy resin microcapsule core material had good curing activity and possessed the ability to play the healing role in cementitious composite. Healing temperature and healing age had less impact on the healing effect of the microcapsule in cementitious composite. The microcapsule could be kept good shape in cement paste and combined with cement paste closely. The microcapsule also could rupture and had better dispersion in cement paste. The main fracture behavior of the microcapsule was based on small hole ruptured when cement paste did not occur macro damage. When pre-loading was 0.75 σmax, the particle size of microcapsules was range from 75 μm to 150 μm, proportion of epoxy curing agent was 20 % and proportion of the microcapsule was 6 %, early age strength healing ratio reached the highest of 24.1 %.

Self-Healing Mortar

2019 ◽  
pp. 135-148
Keyword(s):  
Epoxy Resin ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Experimental Program ◽  
Self Healing ◽  
Repair Materials ◽  
Healing Agent ◽  
The Cost ◽  
Initial Reading

The cost of repairing cracked concrete is expensive as it requires special repair materials and skilled labour. Thus, the developments of new materials, like self-healing materials, are highly needed to repair cracks automatically and to restore or even increase concretes' strength to prolong its service life. The aim of this chapter was to investigate the performance of epoxy resin without hardener as a self-healing agent in mortar. A detailed introduction of self-healing mortar is given followed by a problem statement. The epoxy resin as a self-healing material is also explained briefly. Self-healing concept is also discussed in detail followed by the experimental program. Results revealed that the epoxy resin without hardener as a healing agent performed effectively as the compressive strength and ultrasonic pulse velocity of 365 days old cracked mortar samples regained the initial reading with prolonged curing time.

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