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Chemical Engineering Commons

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2004

Papers in Molecular Chemistry

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Full-Text Articles in Chemical Engineering

Chemical/Mechanical Analyses Of Anhydride-Cured Thermosetting Epoxys: Dgeba/Nma/Bdma, Wei Chian, Delmar C. Timm Sep 2004

Chemical/Mechanical Analyses Of Anhydride-Cured Thermosetting Epoxys: Dgeba/Nma/Bdma, Wei Chian, Delmar C. Timm

Papers in Molecular Chemistry

The chemical state of cure in a thermosetting resin was used to predict the resin’s equilibrium modulus. High performance liquid chromatography analyses of the sol fraction yielded molar dynamics for monomeric, oligomeric, and polymeric molecules. Their population density distributions were compared with theoretical predictions based on a chain-growth polymerization mechanism. The resulting chemical estimates of the state of cure were integrated into calculations yielding concentrations of network structures within the gel that contribute to the density of elastically active strands and junctions. The theory of rubber elasticity was then used to predict the equilibrium modulus. Measurements incorporated dynamic mechanical analysis. …


Kinetic Reaction Analysis Of An Anhydride-Cured Thermoplastic Ep-Oxy:Pge/Nma/Bdma, Wei Chian, Delmar C. Timm Sep 2004

Kinetic Reaction Analysis Of An Anhydride-Cured Thermoplastic Ep-Oxy:Pge/Nma/Bdma, Wei Chian, Delmar C. Timm

Papers in Molecular Chemistry

A comprehensive reaction analysis of a linear epoxy resin cured with an anhydride was performed to evaluate the reaction rate expressions. Monomers included phenyl glycidyl ether and methyl- 5-norbornene-2,3-dicarboxylic anhydride or nadic methyl anhydride; the catalyst was N,N-dimethylbenzylamine; the initiator was n-propanol. Emphasis was initially placed on the molar dynamics of monomeric and oligomeric molecules. Molecular fractionations were achieved using reversed phase, high performance liquid chromatography. Chemical reaction rate constants were examined as a function of degree of polym-erization. For the chain-initiated polymerization, the initiation rate constant was observed to be approximately 3 times greater than the propagation constant associated …