Theoretical study of the reactions of ethylene oxide and ammonia: a model study of the epoxy adhesive curing mechanism

We present the first experimental demonstration of c-Si based photocathode for hydrogen production under back-illumination with theoretical model study.

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Curing Mechanism Study for Dual Cure of Epoxy Adhesive by Differential Scanning Calorimetry

Materials Science Forum ◽

10.4028/www.scientific.net/msf.864.3 ◽

2016 ◽

Vol 864 ◽

pp. 3-7

Author(s):

Waefatimah Waenawae ◽

Santi Pumkrachang ◽

Syahril bin Zainudin ◽

Thammasit Vongsetskul ◽

Tanakorn Osotchan

Keyword(s):

Differential Scanning Calorimetry ◽

Uv Light ◽

Heating Time ◽

Epoxy Adhesive ◽

Curing Process ◽

Mechanism Study ◽

Scanning Calorimetry ◽

Heat Curing ◽

Heat Cure ◽

Curing Mechanism

Epoxy adhesive used in electronic packaging could normally be cured by ultraviolet light, heat at high temperature or dual cured by both processes. Differential scanning calorimetry (DSC) has been used to identify and analyze the occurred reaction during the curing process. The structural modification of epoxy during curing could be examined by measuring its thermal properties, and the change in molecular structure of epoxy could be observed by a relative small area of DSC peak. This provided the heat amount required for complete cure. It is found that the DSC peak area after heat cure at 90 °C increased linearly as a function of heating time while that at 120 °C decreased exponentially. For UV cure, it indicated that the curing mechanism was strongly depend on the energy from UV light. For dual cure at 90 °C, the heat curing time could be reduced from single curing process of 50 minutes to 6 minutes, while the heating time for dual cure at 120 °C could be reduced from 4 minutes to 2 minutes.

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Theoretical Study on Structures and Reaction Mechanisms of Ethylene Oxide Hydration over H-ZSM-5: Ethylene Glycol Formation

The Journal of Physical Chemistry C ◽

10.1021/jp8034677 ◽

2008 ◽

Vol 112 (33) ◽

pp. 12914-12920 ◽

Cited By ~ 31

Author(s):

Thana Maihom ◽

Supawadee Namuangruk ◽

Tanin Nanok ◽

Jumras Limtrakul

Keyword(s):

Ethylene Oxide ◽

Ethylene Glycol ◽

Reaction Mechanisms ◽

Theoretical Study

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Molecular modeling of reduction reactions of dicyandiamide on zinc: a theoretical study of epoxy adhesive/galvanized steel adhesion

Journal of Adhesion Science and Technology ◽

10.1163/156856190x00414 ◽

1990 ◽

Vol 4 (1) ◽

pp. 443-452 ◽

Cited By ~ 17

Author(s):

Joseph W. Holubka ◽

James C. Ball

Keyword(s):

Molecular Modeling ◽

Theoretical Study ◽

Epoxy Adhesive ◽

Galvanized Steel ◽

Reduction Reactions

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Dipped adcluster model study for the end-on chemisorption of O2 on an Ag surface

Canadian Journal of Chemistry ◽

10.1139/v92-058 ◽

1992 ◽

Vol 70 (2) ◽

pp. 404-408 ◽

Cited By ~ 26

Author(s):

Hiroshi Nakatsuji ◽

Hiromi Nakai

Keyword(s):

Ground State ◽

Cluster Model ◽

Lower Energy ◽

Theoretical Study ◽

Coupling Model ◽

Spin Coupling ◽

Adsorbed Species ◽

Net Charge ◽

Model Study ◽

Lower Energy Region

Theoretical study for the end-on adsorption of an O2 molecule on an Ag surface is carried out with the use of the dipped adcluster model (DAM). The adcluster of AgO2 is taken and the highest spin coupling model is employed. Electron transfer from the bulk metal to the adcluster considered by DAM is important for the occurrence of the chemisorption, and this cannot be described by the small-size cluster model. Electron correlations are also quite important and are described by the SD-CI method based on the corresponding parent configurations. In the end-on geometry, the superoxide species is the ground state, and there are no peroxide species in the lower energy region. The calculated adsorption energy compares reasonably with the experimental value. The O—O axis of the superoxide is inclined by 70°–80° from the surface normal. The outside oxygen atom of the adsorbed species seems to be more reactive than the inside one, while the net charge on the former is smaller than that on the latter. Keywords: DAM (dipped adcluster model), silver, superoxide, chemisorption.

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