Kinetic analysis of a fast reacting thermoset system

Prime, R. Bruce; Michalski, C.; Neag, C. M.

doi:10.1016/j.tca.2004.11.029

Cited by 28 publications

(19 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…DSC has been widely used to study thermoset reactions in both isothermal and nonisothermal modes 14–23. Kinetic analysis by DSC assumes that the amount of heat generated from a reaction (Δ H T ) is directly proportional to the degree of cure (or the extent of reaction) and therefore the rate of cure d α /d t can be related to the heat generated by the following equation 24…”

Section: Introductionmentioning

confidence: 99%

Reaction Kinetics of Polyurethane Formation Using a Commercial Oligomeric Diisocyanate Resin Studied by Calorimetric and Rheological Methods

Papadopoulos

Ginic‐Markovic

Clarke

2008

Macro Chemistry & Physics

View full text Add to dashboard Cite

Reaction rate and kinetics of cure between PMDI and castor oil, a tri‐functional polyol, for stoichiometric and off‐stoichiometric mole ratios, were studied through isoconversional analysis of DSC data and through gelation times and viscosity build up obtained through rheological techniques. The cure kinetics of the polyurethane reaction as monitored using different techniques gave similar activation energies for the stoichiometric ratio. Isoconversional analysis of DSC data showed a competitive reaction scheme for the stoichiometric system, suggesting the presence of isocyanate groups with different reactivities in the PMDI, which was further substantiated in rheological investigations.magnified image

show abstract

Section: Introductionmentioning

confidence: 99%

Reaction Kinetics of Polyurethane Formation Using a Commercial Oligomeric Diisocyanate Resin Studied by Calorimetric and Rheological Methods

Papadopoulos

Ginic‐Markovic

Clarke

2008

Macro Chemistry & Physics

View full text Add to dashboard Cite

show abstract

“…Although the rheology and cure kinetics of slow-curing epoxies have been studied and modelled [2][3][4][5], the use of fast-curing systems gives new challenges [6,7]. To achieve the short cure times the mould is pre-heated, so the degree of cure and viscosity of the epoxy evolve as a function of time whilst the mould is being filled, and so these must be considered as variables for flow modelling.…”

Section: Introductionmentioning

confidence: 99%

“…Yang et al [6] found that the total heat of reaction from isothermal measurements decreases at higher temperatures because the heat flow is not measured correctly in the initial stage of curing. To overcome this, Prime et al [7] extrapolated isothermal curing curves from dynamic measurements for fast-curing resins.…”

Section: Introductionmentioning

confidence: 99%

Fast-curing epoxy polymers with silica nanoparticles: properties and rheo-kinetic modelling

et al. 2015

View full text Add to dashboard Cite

Fast-curing epoxy polymers allow thermoset parts to be manufactured in minutes, but the curing reaction is highly exothermic with heat flows up to 20 times higher than conventional epoxies. The low thermal conductivity of the polymer causes the mechanical and kinetic properties of parts to vary through their thickness. In the present work, silica nanoparticles were used to reduce the exotherm, and hence improve the consistency of the parts. The mechanical and kinetic properties were measured as a function of part thickness. The exothermic heat of reaction was significantly reduced with the addition of silica nanoparticles, which were well dispersed in the epoxy. The silica nanoparticles increased the Young's modulus linearly from 3.6 to 4.6 GPa with 20 wt% of silica, but the fracture energy was found to increase less than for many slow-curing epoxy resins, with values of 176-211 J m -2 being measured. Although there was no additional toughening, shear band yielding was observed. Further, the addition of silica nanoparticles increased the molecular weight between crosslinks, indicating the relevance of detailed cure kinetics when studying fast-curing epoxy resins. A model was developed to describe the increase in viscosity and degree of cure of the unmodified and the silica-modified epoxies. A heat transfer equation was used to predict the temperature and resulting properties through the thickness of a plate, as well as the effect of the addition of silica nanoparticles. The predictions were compared to the experimental data, and the agreement was found to be very good.

show abstract

Section: Introductionmentioning

confidence: 99%

“…Assuming that each cross-linking can releases the same amount of energy, the heat released in curing reaction can be utilized to monitor the curing process. Differential scanning calorimetry (DSC) technology is very capable of measuring thermal characterization of many materials, especially polymers [1,2,3,4].There have been many studies on the modeling or simulation of curing process of polymers [5,6,7,8]. In these works, the thermal properties in the cure circle were calculated mostly with one-or two-dimensional finite difference method.…”

mentioning

confidence: 99%

Cure kinetics analysis and simulation of silicone adhesives

Zhang

Song

Wang

et al. 2009

2009 International Conference on Electronic Packaging Technology &Amp; High Density Packaging

View full text Add to dashboard Cite

A nonlinear transient heat transfer finite element model based on commercial finite element software, ABAQUS, is developed to simulate the curing process of silicone adhesive. The curing reaction process and specific heat of the silicone adhesive were investigated using a differential scanning calorimetry (DSC) to obtain material parameters for numerical simulations. Curing reaction kinetics was derived. Using the user subroutine HETVAL of ABAQUS, temperature distributions inside silicone can be evaluated by solving the heat conduction equations including internal heat generation produced by curing reactions. Good agreement between experimental data and numerical analysis by ABAQUS is obtained. IntroductionSilicone materials are well established products used in many applications. For electronics applications, silicone adhesives have demonstrated good performance. They have a high degree of flexibility to significantly increase the reliability and life of the devices because of the stressrelieving properties. They can also maintain the stressrelieving nature over a wide temperature or humidity range.The physical, chemical, and mechanical properties of the polymer are significantly affected by the curing behavior. The silicone adhesive requires the proper temperatures and time to achieve full cure and the best properties. Thus a thorough understanding of the vulcanization mechanism is desirable for better control of the curing process of silicone adhesives.The silicone adhesive studied in this work is a thermally curable, addition-curing, two-part, LTV silicone rubber. A hydrosilylation reaction will happen when sufficient heat is applied. Assuming that each cross-linking can releases the same amount of energy, the heat released in curing reaction can be utilized to monitor the curing process. Differential scanning calorimetry (DSC) technology is very capable of measuring thermal characterization of many materials, especially polymers [1,2,3,4].There have been many studies on the modeling or simulation of curing process of polymers [5,6,7,8]. In these works, the thermal properties in the cure circle were calculated mostly with one-or two-dimensional finite difference method. Finite element analysis was used just in recent years. The numerical software people used to study the curing process were the developed special-purpose or general-purpose software, just like ANASYS and ABAQUS. The internal heat generation produced by cure reactions can

show abstract

Kinetic analysis of a fast reacting thermoset system

Cited by 28 publications

References 8 publications

Reaction Kinetics of Polyurethane Formation Using a Commercial Oligomeric Diisocyanate Resin Studied by Calorimetric and Rheological Methods

Reaction Kinetics of Polyurethane Formation Using a Commercial Oligomeric Diisocyanate Resin Studied by Calorimetric and Rheological Methods

Fast-curing epoxy polymers with silica nanoparticles: properties and rheo-kinetic modelling

Cure kinetics analysis and simulation of silicone adhesives

Contact Info

Product

Resources

About