Adhesive technology – Key to future of lightweight design?

Ickert, Leif

doi:10.1365/s35784-012-0058-0

Cited by 5 publications

(7 citation statements)

References 9 publications

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“…Adhesive bonding is a key industrial manufacturing process of joining materials . Recently, advanced technologies requiring extensive use of adhesive bonding, such as multimaterial design with proper mixing of metals and polymers for lightweight automobile bodies, − tight packing of electronic components requiring rapid heat dissipation, , and additive manufacturing for novel materials, have become increasingly popular. In the case of automobile manufacture, currently, resistance spot welding dominates, but adhesive bonding is expected to overtake this traditional technology in the next 10 years .…”

Section: Introductionmentioning

confidence: 99%

First-Principles Calculations of the Protonation and Weakening of Epoxy Resin under Wet Conditions

et al. 2021

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In this study, we investigated the protonation of the amine group in epoxy resins prepared using amine-based curing agents by theoretical methods. Density functional theory (DFT)based free-energy calculations of the corresponding deprotonation subreactions showed that the amine group of the epoxy resin is protonated at equilibrium depending on the location of the amine group when the epoxy resin is embedded in water under standard conditions. Additional DFT calculations demonstrate that the energetic barrier for breaking the ether bond of the epoxy resin is lowered by about 0.6 eV as a result of the cooperative effect of H 2 O dissociation and that the transition-state energy for breaking the amine group bond is lowered by about 0.4 eV after the protonation of the amine group. Comparing the transition-state energies, we predict that the bond breakage of the protonated amine groups is the principal process causing the weakening of epoxy resins under wet conditions.

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Section: Introductionmentioning

confidence: 99%

First-Principles Calculations of the Protonation and Weakening of Epoxy Resin under Wet Conditions

et al. 2021

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“…1 Increased usage of such a resin adhesion is expected for reduction of automotive weight. 2 The power semiconductor device is an essential component for an electrically powered automobile. Next generation power device that utilizes a wide band gap semiconductor, such as SiC and GaN, requires an advanced (e.g., filler mixed) adhesive resin with improved close contactness to dissipate the intense heat of the device.…”

Section: Introductionmentioning

confidence: 99%

“…Metallic and nonmetallic parts of the automobile framework are bonded, in part, using the epoxy resin as adhesive glue . Increased usage of such a resin adhesion is expected for reduction of automotive weight . The power semiconductor device is an essential component for an electrically powered automobile.…”

Section: Introductionmentioning

confidence: 99%

Moisture-Induced Reduction of Adhesion Strength between Surface Oxidized Al and Epoxy Resin: Dynamics Simulation with Electronic Structure Calculation

Ogata

Takahashi²

2016

J. Phys. Chem. C

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Adhesion strength between metal and epoxy resin is well-known to reduce significantly in a moist environment. To theoretically understand its mechanisms, we calculate the shear strength of the interfacial adhesion between the surface oxidized Al and bisphenol A epoxy resin with a varying number of water molecules or hydroxide ions inserted inbetween using the hybrid quantum-classical simulation method. The quantum region in the hybrid method, which is composed of about thousand atoms at the interface, is treated by the electronic density-functional theory implemented to calculate on a real-space grid. It is thereby found that the adhesion strength reduces more significantly as the degree of the moisture content increases, in accordance with the experimental observations. Microscopic analyses find the following key features: (i) The interatomic Al–O bond between the Al atom of the oxide and the O atom of the epoxide group in the epoxy resin contributes substantially to the strength of the interfacial adhesion. (ii) Dissociation of the O atom of the epoxide group forming such an Al–O bond is enhanced when an H2O rather than an OH resides in close proximately to the bond. (iii) The epoxy resin becomes more plastic by incorporating H2O molecules. Both (ii) and (iii) act to weaken the shear strength of the interfacial adhesion.

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“…Adhesive bonding has attracted renewed interest from the manufacturing industry due to its role in creating composite materials , and multimaterial designs , with the desired arrangements of polymers and metals. Such materials are of particular desire in the development of lightweight automobile bodies and airframes .…”

Section: Introductionmentioning

confidence: 99%

Protonation of Strained Epoxy Resin under Wet Conditions via First-Principles Calculations Using the H⁺-Shift Method

Ogata

Uranagase

2023

J. Phys. Chem. B

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A significant challenge in adhesive bonding is the accelerated breaking of stretched adhesives under wet conditions, which is known as cohesive failure. One group of commonly used adhesives consists of the amine-cured epoxy resins. Based on deprotonation free-energy calculations of the unstrained resin in water, it has recently been proposed that these adhesives can undergo failure through breakage originating at the protonated amine group under neutral or acidic conditions [J. Phys. Chem. B 2021, 125, 8989–8996]. In this study, we comprehensively investigated the degree of protonation of the amine group under both stretched and compressed conditions by devising a robust first-principles protonation calculation method applicable to strained materials. It was found that the amine group was partially protonated in neutral water at 298 K and that the amine group was protonated when the epoxy resin was stretched to a greater extent in water, and vice versa. These findings support the physicochemical cause of cohesive failure due to protonation of the amine group in the stretched amine-cured epoxy resins.

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Adhesive technology – Key to future of lightweight design?

Cited by 5 publications

References 9 publications

First-Principles Calculations of the Protonation and Weakening of Epoxy Resin under Wet Conditions

First-Principles Calculations of the Protonation and Weakening of Epoxy Resin under Wet Conditions

Moisture-Induced Reduction of Adhesion Strength between Surface Oxidized Al and Epoxy Resin: Dynamics Simulation with Electronic Structure Calculation

Protonation of Strained Epoxy Resin under Wet Conditions via First-Principles Calculations Using the H⁺-Shift Method

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Adhesive technology – Key to future of lightweight design?

Cited by 5 publications

References 9 publications

First-Principles Calculations of the Protonation and Weakening of Epoxy Resin under Wet Conditions

First-Principles Calculations of the Protonation and Weakening of Epoxy Resin under Wet Conditions

Moisture-Induced Reduction of Adhesion Strength between Surface Oxidized Al and Epoxy Resin: Dynamics Simulation with Electronic Structure Calculation

Protonation of Strained Epoxy Resin under Wet Conditions via First-Principles Calculations Using the H+-Shift Method

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Protonation of Strained Epoxy Resin under Wet Conditions via First-Principles Calculations Using the H⁺-Shift Method