Kinetics of Curing of Unsaturated Polyesters in the Presence of Organic and Inorganic Fillers

Simitzis, Johannes; Stamboulis, Artemis; Tsoros, Dimitrios; Martakis, N.

doi:10.1002/(sici)1097-0126(199708)43:4<380::aid-pi816>3.0.co;2-3

Cited by 18 publications

(13 citation statements)

References 2 publications

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“…The unsaturated groups in the polyester monomers copolymerize with styrene to form a crosslinked network via bulk polymerization. Five stages of induction, microgelation, transition, macrogelation, and postgelation are suggested in crosslinking of UP resins [13, 14]. Generally, organic peroxides are used as the source of free radical in the curing of UP resins.…”

Section: Introductionmentioning

confidence: 99%

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Kinetic modeling of nanoclay‐reinforced unsaturated polyester resin

2011

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Curing behavior of an unsaturated polyester (UP) resin containing 1 wt% organically modified clay (OMC) catalyzed with methyl ethyl ketone peroxide (MEKP) initiator and promoted by cobalt naphthenate accelerator was investigated by dynamic differential scanning calorimetry (DSC) at five different heating rates of 5, 10, 15, 20, and 25°C/min. X‐ray diffraction and transmission electron microscopy were used to evaluate the morphology of UP/OMC composites. Results showed a mixture of intercalated and exfoliated morphology. The dynamic DSC curing curves showed a bimodal exothermic peak; therefore, two independent reactions, namely, redox and thermal copolymerizations were assumed. Kinetic parameters were calculated by using autocatalytic model and using Down hill simplex method and Runge–Kutta algorithm for each reaction. The addition of nanoclay resulted in decrease of the activation energy of the redox reaction compared to that of the neat UP resin. Also, the pre‐exponential factor of the first reaction for UP/OMC was less than that of the neat UP. Two factors including decreasing the activation energy and decreasing the number ofcollisions of reactionary components finally resulted in increasing the reaction rate of the first reaction out of the whole reaction in the system containing nanoclay compared to the neat UP resin. It is interesting that nanoclay has no effect on the thermal decomposition reaction. POLYM. COMPOS., © 2011 Society of Plastics Engineers.

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Section: Introductionmentioning

confidence: 99%

“…Simtizis and coworkers [13] studied the dynamic curing kinetics of UP resin at the presence of organic and inorganic fillers. In their research, the kinetic parameters of curing reaction at heating rate 10°C/min were calculated, while taking into consideration only one reaction.…”

Section: Introductionmentioning

confidence: 99%

Kinetic modeling of nanoclay‐reinforced unsaturated polyester resin

2011

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“…During the curing, the CoNp forms a redox system with the peroxide initiator MEKP. The Co 2+ of the CoNp is quickly oxidized to Co 3+ and the latter is slowly reduced to Co 2+ ; in both cases radicals are formed 8,24. For the curing of most polyesters, the usual amount of CoNp (1 ml per 100 g of UP‐S) has been used which leads to decomposition of the initiator and to a small amount of CoNp remaining.…”

Section: Discussionmentioning

confidence: 99%

“…Often, the catalyst cannot easily be separated from the polyester and it remains in the bulk mass of the product. The curing process of unsaturated polyesters, including appropriate kinetic models, has been widely studied, especially by DSC using various conditions and substances, such as promoter, initiator, fillers etc 8–13. The additives can affect the curing of unsaturated polyesters 8.…”

Section: Introductionmentioning

confidence: 99%

“…The curing process of unsaturated polyesters, including appropriate kinetic models, has been widely studied, especially by DSC using various conditions and substances, such as promoter, initiator, fillers etc 8–13. The additives can affect the curing of unsaturated polyesters 8. In this work, unsaturated polyesters are firstly synthesized by varying the composition of the raw materials in the presence or absence of catalysts and then are cured with an appropriate curing system.…”

Section: Introductionmentioning

confidence: 99%

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Effect of composition and polyesterification catalysts on the optical properties of cured polyesters

Simitzis

Zoumpoulakis

Soulis

2002

Polymer International

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Unsaturated polyesters based on ethylene glycol have been synthesized using a variety of anhydride, saturated and unsaturated dicarboxylic acids and various catalysts. The structure of the polyesters and the effect of the different compositions on the colour of cured polyesters are studied by FTIR, DSC and colorimetry. The structure of cured polyesters greatly depends on the isomerization of maleic acid to fumaric acid during polyesterification. The colour of unsaturated polyesters cured with the most common curing system (MEKP as initiator and CoNp as accelerator) is firstly influenced by the curing accelerator CoNp via the d–d transitions of the transition metal cobalt. Secondly, the composition of the dicarboxylic acids and anhydride used in the polyesterification influences the colour of the polyesters which depends especially on the isomerization of maleic acid. The cured maleate polyesters have more unreacted double bonds and more polar structure because of the presence of carbonyl groups, compared to the corresponding fumarate polyesters, and this structure affects the colour. The residual catalysts from the polyesterification have minor influence on the colour of cured polyesters. Copyright © 2002 Society of Chemical Industry

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Effect of reactive polyurethane on toughness of unsaturated polyester resin

Min

Hwang

Choi

et al. 2002

J of Applied Polymer Sci

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Unsaturated polyester (UP) resin is one of the major thermosetting resins and is very useful as a matrix resin of composite material for its processibility. UP resin, however, has several shortcomings: it is weak in alkalis, volume shrinkage occurs during the crosslinking reaction of the oligomeric UP resin with a styrene monomer, and it is also brittle. The mechanical properties of UP resin can be enhanced by blending it with various materials. In this study, polyurethane (PU) was used as a modifier to improve the toughness of the UP resin. The effect of the polyol molecular weight as a PU soft segment and the PU contents on the toughness of PU-modified UP resins were studied. A UP/PU polymer network may occur through a reaction between an isocyanate group in the methyl diisocyanate (MDI) and a hydroxyl one in the UP molecules. The maximum toughness was observed at approximately 2 wt % of the PU content. These results can be rationalized by the incorporation of a rubbery PU segment into a brittle UP resin.

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Kinetics of Curing of Unsaturated Polyesters in the Presence of Organic and Inorganic Fillers

Cited by 18 publications

References 2 publications

Kinetic modeling of nanoclay‐reinforced unsaturated polyester resin

Kinetic modeling of nanoclay‐reinforced unsaturated polyester resin

Effect of composition and polyesterification catalysts on the optical properties of cured polyesters

Effect of reactive polyurethane on toughness of unsaturated polyester resin

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