Curing of alkyds based on semi-drying oils with melamine resin

Jovičić, Mirjana; Radičević, Radmila; Budìnski‐Simendìć, Jaroslava

doi:10.1007/s10973-008-9004-4

Cited by 26 publications

(20 citation statements)

References 26 publications

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“…The main advantage of transforming the dynamic data for alkyd/melamine mixture resins into the isothermal ones is the possibility to obtain the curves of apparent curing degrees versus time ( Figure 6) at any curing temperature of interest [11,16]. The data obtained from dynamic DSC using Ozawa-Flynn-Wall method were compared with those obtained by isothermal DSC experiments (at 120 °C) and the results are summarized in Figure 6 for all samples.…”

Section: Transformation Of Dynamic Dsc Results Into Isothermal Datamentioning

confidence: 99%

“…It is necessary to study the extent of the curing and kinetic parameters, in order to obtain high performance resins. The curing behaviour of the alkyds was studied using DSC in numerous researches [12][13][14][15][16][17]. DSC technique has the advantage of being based on the relationship between the heat flow and reaction rate of the resin curing process [10,11].…”

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confidence: 99%

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Isoconversional kinetic analysis of the alkyd/melamine resins curing

Jovičić

Radičević

Pavličević

et al. 2013

CI&CEQ

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The curing reaction for the mixtures of alkyd resins based on ricinoleic acid, phthalic anhydride and three polyols (glycerin, trimethylolpropane or ethoxylated pentaerythritol) with two different commercial melamine resins was investigated by differential scanning calorimetry (DSC). The curing kinetics analysis was performed using the isoconversional methods (Ozawa-Flynn-Wall, Kissinger-Akahira-Sunose and Friedman). Isoconversional methods were carried out with three heating rates (5, 10 and 20°C/min) in a scanning temperature range from 40 to 250°C. It was found that the curing activation energy of resin mixtures is influenced by alkyd and melamine resin type due to the catalytic effect of hydroxyl group on the reactions. The dependence of apparent curing degree on time, which was obtained by mathematical transformations of dynamic DSC data using Ozawa-Flynn-Wall method, describes well the isothermal DSC experiments

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Section: Transformation Of Dynamic Dsc Results Into Isothermal Datamentioning

confidence: 99%

mentioning

confidence: 99%

Isoconversional kinetic analysis of the alkyd/melamine resins curing

Jovičić

Radičević

Pavličević

et al. 2013

CI&CEQ

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“…The amount of polymerized monomer (proportional to the heat evolved during reaction) was calculated from the area between the isothermal DSC curve and the baseline, using the method described in the literature. 20,25,26 The amount of unreacted monomer was determined by prolonging the polymerization in the dynamic thermal range, from the temperature of isothermal polymerization to 220 1C, at a heating rate of 10 1C min À1 . 20,25 RESULTS AND DISCUSSION DSC thermograms of styrene-free radical bulk polymerizations at different temperatures are presented in Figure 1.…”

Section: Methodsmentioning

confidence: 99%

A new approach for the kinetic modeling of free radical bulk polymerization of styrene

Bera

Radičević

Stoiljkovic

et al. 2011

Polym J

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The kinetics of styrene-free radical bulk polymerization was studied by differential scanning calorimetry (DSC). The data obtained from DSC thermograms were used to model and predict the autoacceleration during styrene polymerization and to understand how it is influenced by temperature. The experimental data were well described by the estimated kinetic model. The model included two processes (the first-order reaction and autoacceleration), because they occur simultaneously as two parallel reactions rather than being strictly separated. It was found that the autoacceleration activation energy is approximately four times lower than the energy of the first-order reaction. In addition, the first-order reaction followed by the autoacceleration of the styrene-free radical bulk polymerization occurs simultaneously only between 41.7 and 110.5 1C. Keywords: autoacceleration; differential scanning calorimetry; polymerization kinetics; polystyrene; styrene-free radical bulk polymerization INTRODUCTION It is well known that the free radical bulk polymerization of vinyl monomers (derivates of acrylic and methacrylic acids, vinyl acetate, styrene, ethylene and so on) is characterized by the autoacceleration phenomenon. 1-3 The free radical polymerization of these monomers can be explained by classical theory up to definite conversion. After that conversion, autoacceleration of polymerization occurs. The onset of autoacceleration is the moment when the polymerization rate departs from the value anticipated by the classical theory of free radical polymerization. [3][4][5][6][7] The onset and the intensity of autoacceleration are determined by the type of monomer, initiator concentration, temperature and other reaction conditions. Ebdon and Hunt 3 used differential scanning calorimetry (DSC) to follow the course of free radical bulk polymerization of styrene and concluded that autoacceleration is less pronounced at 90 1C than at 80 1C and is absent at 100 1C and above. Autoacceleration appeared at about 2% conversion of styrene polymerized at 20 1C for 252 days in the presence of 2,2¢-azobisisobutyronitrile. 8 To explain this autoacceleration, an equation was applied to the kinetic data obtained under the condition of predominant transfer to the monomer. It was concluded that polymer molecules may move by repetition and the mobility of segments decreases with decrease of free volume. 8 Comparisons of the results obtained for styrene-free radical bulk polymerization with model predictions have quantified the dependence of the gel effect strength on the predominance of chain transfer events. 9 Cioffi et al. 10 performed a rheokinetic study of the bulk-free radical polymerization of styrene with a helical barrel rheometer. The rheokinetic measurements show that autoacceleration in the free radical polymerization of styrene can be reduced when the polymer-

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“…The oven temperatures were set at 80, 100, 120 and 140 • C. These temperatures were selected after studying a DSC (differential scanning calorimetry) dynamic scan for the uncured sample which showed that curing took place at temperature above 75 • C. When conducting isothermal tests, the oven was preheated to the predetermined isothermal temperature, and then the sample was installed quickly and held at the considered cure temperature. A sol-gel method [14][15][16][17][18] to evaluate the corresponding conversion through the reaction was used.…”

Section: Methodsmentioning

confidence: 99%

The kinetic analysis of isothermal curing reaction of an unsaturated polyester resin: Estimation of the density distribution function of the apparent activation energy

Janković

2010

Chemical Engineering Journal

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Curing of alkyds based on semi-drying oils with melamine resin

Cited by 26 publications

References 26 publications

Isoconversional kinetic analysis of the alkyd/melamine resins curing

Isoconversional kinetic analysis of the alkyd/melamine resins curing

A new approach for the kinetic modeling of free radical bulk polymerization of styrene

The kinetic analysis of isothermal curing reaction of an unsaturated polyester resin: Estimation of the density distribution function of the apparent activation energy

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