Cure modeling and monitoring of epoxy/amine resin systems. II. Network formation and chemoviscosity modeling

Karkanas, Panagiotis; Partridge, Ivana K.

doi:10.1002/1097-4628(20000906)77:10<2178::aid-app11>3.0.co;2-0

Cited by 71 publications

(61 citation statements)

References 13 publications

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“…In these models, some or all of the following steps are undertaken: (1) to separate the different peaks by means of a Gaussian distribution (it is an necessary step when a DSC thermo-gram displays one or more shoulders [18], (2) to find the Arrhenius parameters by means of the ASTM E698 method, (3) to evaluate the rest of the kinetic parameters by means of a nonlinear regression technique, and (4) to determine the relative weight of each reaction rate to the total. Grentzer et al [19] used the ASTM E698 methodology to monitor the cure of novolac modified vinyl ester and they found an activation energy for each DSC peak.…”

Section: Introductionmentioning

confidence: 99%

Kinetic analysis of two DSC peaks in the curing of an unsaturated polyester resin catalyzed with methylethylketone peroxide and cobalt octoate

Martin

2006

Polymer Engineering & Sci

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The curing of an unsaturated polyester resin catalyzed with methylethylketone peroxide and cobalt octoate as promoter is studied by DSC at different heating rates. A high promoter/peroxide ratio is used. The DSC curves show two exothermic peaks. It has been assumed that they represent two independent cure reactions. A set of kinetic parameters for each DSC peak has been obtained. They describe the overall cure process using an empirical kinetic model. Nth order and autocatalytic kinetic functions have been employed. A computer program was developed to calculate the degrees of conversion associated with each peak, and to evaluate the kinetic parameters. The calculation algorithm uses the Runge-Kutta numerical integration and the ' 'downhill simplex method.' ' This methodology permits to find all kinetic parameters simultaneously. DSC experimental data are very well fitted. The simulated first peak occurs always before the second one, and the fraction of reaction heat associated with the first peak over the overall reaction heat decreases with heating rate. Moreover, activation energies are in good agreement with the tabulated values for typical free radical polymerization induced by thermal and redox decomposition of the peroxides. POLYM. ENG. SCI., 47:62-70, 2007.

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Section: Introductionmentioning

confidence: 99%

Kinetic analysis of two DSC peaks in the curing of an unsaturated polyester resin catalyzed with methylethylketone peroxide and cobalt octoate

Martin

2006

Polymer Engineering & Sci

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“…A brief introduction for these models can be found in other papers. [13] In this study, we have attempted to develop a systematic methodology to investigate the rheology property of the wafer level underfill. A semi-empirical model was developed to predict the viscosity of the underfill during reflow processes.…”

Section: Introductionmentioning

confidence: 99%

Rheology Study of Wafer Level Underfill

Sun

Zhang

Wong

2005

Macro Materials & Eng

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Summary: As a special epoxy resin material used in the electronics packaging, wafer level underfill (WLU) is studied using a chemorheology approach to provide a fundamental understanding of its reaction dependent rheology behaviors. In this work, the relationship between the molecular weight ($\overline M _{\rm w}$) and the viscosity of the epoxy resins at fixed temperatures has been established. Subsequently an Arrhenius‐Erying equation was used to fit the relationship between viscosity and temperature for given molecular weight epoxies. By combining the two relationships, the viscosity could be modeled as a function of temperature and molecular weight. To obtain the viscosity change of the WLU during the reflow process, the molecular weight change of the underfill was calculated from the degree of curing through the kinetics modeling. A semi‐empirical model was developed to predict the viscosity of the underfill as a function of time and temperature during the curing process. Modeled predictions were compared with experimental data under isothermal and ramping temperatures during curing experiments. The model showed good agreement with the experiments in the early stage of curing reaction. The critical viscosity of the underfill for solder wetting was obtained by wetting experiments, which can be used as the criteria to determine the flowability of the wafer level underfill.Data fitting of the viscosity model at isothermal condition.magnified imageData fitting of the viscosity model at isothermal condition.

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“…The gel point in rheological experiments is determined using various methods, according to different definitions [42,43]: the divergence point or fixed level of the viscosity [44,45], the crossover point of the dynamic storage modulus (G') and loss modulus (G") [46], or the point at which the loss tangent becomes independent of testing frequency [47][48][49][50]. The gel point for NPU-2d, as the crossover point of G' and G" appears at 116.5°C as can be seen in Figure 8a.…”

Section: Rheological Behaviourmentioning

confidence: 99%

Polyurethanes based on thermoreversible networks designed by Diels-Alder reaction

Ursache¹,

Găină²,

Gaina³

2017

Express Polym. Lett.

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Polyurethanes appeared as a Bayer's response to the successful development of high molecular weight polyamides by E.I. Dupont, given the competition between the two companies. The need for PUs steadily increased ever since then, because of its high abrasion, chemical resistance, flexibility, and good mechanical property [1]. Nowadays they are considered one of the most versatile polymeric materials class since they can be used in many forms and in a large number of applications including elastomers [2][3][4][5], flexible and rigid foams [6][7][8], biomedical applications [9][10][11], adhesives and coatings [12][13][14], polymers for electronics [15], etc. The reaction between diisocyanates or multiisocyanates and di-or polyols generates polyurethanes with different molecular structures varying from linear to crosslinked ones depending on the structure, functionality and stoichiometry of the reactants. These thermosetting polymers cannot be reprocessed or reused if, according to the desired applications, chemical crosslinkers are used [16]. For de-crosslinking of polyurethane networks, dynamic covalent chemistry is used, especially by means of the DA and retro-DA (rDA) reactions [17]. Due to its reversibility the DA reaction also represents a choice to create self-healing properties for polymer networks [18]. Concerning polyurethane, the DA reaction was employed in thermally remendable linear polymers [19][20][21][22] and thermally reversible networks [23][24][25][26][27]. The latter were designed in three different ways: i) by polymerization reaction of monomers containing maleimide-furan cycloadduct [26,28], ii) by crosslinking of linear polyurethane containing furan or maleimide pendant groups [27,29,30] and iii) by cycloaddition DA reaction between polyurethane containing furan end groups and multimaleimide monomers [19,[23][24][25][31][32][33]. Abstract. Urethane bismaleimides (BMIs) were used in order to obtain crosslinked structures by their reaction with an aromatic trifuran compound. The Diels-Alder (DA) reaction between the maleimide and furan moieties was investigated using proton nuclear magnetic resonance ( 1 H-NMR) spectroscopy for a model compound (CTF), due to the fact that the networks are insoluble in usual NMR solvents. The structure of the networks was confirmed by infrared spectroscopy. Thermal properties were investigated (by means of differential scanning calorimetry (DSC) and thermogravimetrical analyses (TGA)) and compared with the ones of similar compounds, previously obtained from the same BMIs and a different trifuran compound (which contains tertiary nitrogen in its structure). Mechanical and rheological properties were also investigated. The influence of the nature of the polyol from the BMIs structure and/or the influence of using a trifurylic compound with or without tertiary nitrogen on the properties of the crosslinked networks were also discussed.

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Cure modeling and monitoring of epoxy/amine resin systems. II. Network formation and chemoviscosity modeling

Cited by 71 publications

References 13 publications

Kinetic analysis of two DSC peaks in the curing of an unsaturated polyester resin catalyzed with methylethylketone peroxide and cobalt octoate

Kinetic analysis of two DSC peaks in the curing of an unsaturated polyester resin catalyzed with methylethylketone peroxide and cobalt octoate

Rheology Study of Wafer Level Underfill

Polyurethanes based on thermoreversible networks designed by Diels-Alder reaction

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