Crosslinking of an unsaturated polyester resin in the mould: Modelling and heat transfer studies

Kosar, Vanja; Gomzi, Zoran

doi:10.1016/j.apm.2009.09.004

Cited by 12 publications

(7 citation statements)

References 23 publications

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“…The thermal conductivity constants of UPES-VT and UPES-BDDMA were determined to be 0.1886 and 0.1945 W m −1 K −1 , respectively, closely aligning with values reported for polyester resin in the existing literature. [39] After examining the data showcased in Table 4, it is clear that notable differences are apparent in both electrical volumetric and surface resistivity readings. This observation is consistent with Table 3.…”

Section: Resultsmentioning

confidence: 99%

Functionalized Unsaturated Polyester as Electrical Insulation Varnish

Gümüş,

Aksoy,

Aytac

2024

Macro Chemistry & Physics

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Silsesquioxanes (SQs) are mostly used to provide high‐temperature electrical insulation of resins. In this study, SQ was used to functionalize unsaturated polyester (UPE) varnish and investigate the effect of functionalization on the thermal and electrical properties of UPE varnishes. The solvent‐free varnish incorporates a reactive diluent to decrease viscosity and a catalyst to expedite hardening, eliminating the need for solvents. Vinyl toluene (VT) and 1, 4‐butanediol di methacrylate (BDDMA) serve as hardening agents, consistent with prior research. Various characterization tests, including FTIR, TGA, assessment of thermal conductivity coefficient, and determination of electrical volume‐surface resistance, were conducted to determine the physical, thermal, chemical, and electrical properties of the synthesized SQ functionalized UPE (UPES) varnishes. Results indicate that the UPES‐BDDMA varnish demonstrates the highest thermal decomposition temperature at 438.0 °C, while the UPES‐VT varnish exhibits the highest electrical volume resistance of 2.85 × 1015 Ω·cm. Volatile organic compounds (VOCs) levels in UPE coatings range between 4.9% and 5.10% reflecting the growing demand for eco‐friendly products. It has been shown in this study that the use of BDDMA and VT reactive monomers in the synthesis of SQ functionalized UPE resin and the properties of the resulting varnishes, especially electrical insulation and thermal stability, are improved. This article is protected by copyright. All rights reserved

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Section: Resultsmentioning

confidence: 99%

Functionalized Unsaturated Polyester as Electrical Insulation Varnish

Gümüş,

Aksoy,

Aytac

2024

Macro Chemistry & Physics

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“…BLOCK 1: for each node of the item (already discretized by means of FEMs) at fixed values of the input parameters T n (curing agent temperature) and t c (curing time), temperature profiles are evaluated by solving numerically a Fourier's heat transmission problem in two‐dimensions [45–51]. Since, closed form solutions are rarely available and usually refer to simple geometries, a FEM [52] discretization is needed in the most general case.…”

Section: The Kinetic Numerical Model: a Reviewmentioning

confidence: 99%

“…In the first phase, elastomers are exposed to high temperatures in order to activate crosslinking and thus vulcanization, whereas in the second phase rubber is kept to ambient temperature through air and/or water. In the most general case of 2D items, temperature profiles for each point of the element are obtained solving numerically Fourier's heat equation law [45–51]: where ρ p , c

_{p}^{p}

, and λ p are EPDM density, specific heat capacity, and heat conductivity, respectively; Δ H r (kJ/mol) is rubber specific heat (enthalpy) of reaction and r p [mol/(m 3 sec)] is the rate of crosslinking.…”

Section: The Kinetic Numerical Model: a Reviewmentioning

confidence: 99%

Kinetic finite element model to optimize sulfur vulcanization: Application to extruded epdm weather‐strips

Milani¹

2012

Polymer Engineering & Sci

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A numerical two-phase approach based on experimental scorch curve data fitting, to predict the optimal exposure time and cure temperature of extruded thick items is applied for the study of a real weather-strip. In the first phase, an existing single equation kinetic model is used to predict the crosslinking density under sulfur vulcanization at variable temperatures. The model requires the calibration of only three kinetic constants. The variation with respect to temperature of such parameters is then evaluated by means of two experimental cure curves performed at two different temperatures. In the second phase, kinetic reaction parameters are implemented in finite element software, to perform thermal analyses on an extruded weatherstrip. Once evaluated the final mechanical properties of the item point by point, a set of compression tests is numerically simulated, assuming that the rubber behaves as a Mooney-Rivlin material under the large deformations. Elastic properties of the item are evaluated as a function of the vulcanization degree evaluated in the second phase. It is found that suboptimal vulcanizations result into lower elastic moduli and hence great deformability, sometimes incompatible with real scale engineering applications. POLYM. ENG.

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“…UP also burns rapidly with the formation of char residue of less than 3% due to its high styrene content [5]. Standard economic UP resins or orthophthalic resins are normally used in moderate to low temperature applications due to its low cost, but exhibit poor thermal stability due to low molecular weight [6].…”

Section: Introductionmentioning

confidence: 99%

Effects of silica aerogel particle sizes on the thermal–mechanical properties of silica aerogel – unsaturated polyester composites

Halim

Yajid

Idris

et al. 2017

Plastics, Rubber and Composites

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Silica aerogels with a surface area as high as 773 m 2 g −1 and a density of 0.077 g cm −3 were produced from rice husk via sol-gel process and ambient pressure drying. A particulate composite material was prepared by adding silica aerogel particles of three different particle sizes (powder, granules and bead) to unsaturated polyester resin with a fixed volume fraction of 30%. Thermogravimetric and thermal conductivity studies revealed that silica aerogel composites were having higher thermal stability and thermal insulation than the neat resin. It was suggested that the preservation of aerogel pores from resin intrusion is important for better thermal properties. Larger silica aerogel particles have more porous area (unwetted region) which results in a lower degradation rate and lower thermal conductivity of the base polymer. However, the addition of silica aerogel into resin has reduced the tensile modulus of the polymer matrix where smaller particle size displayed higher toughness than those with bigger particle size.

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Crosslinking of an unsaturated polyester resin in the mould: Modelling and heat transfer studies

Cited by 12 publications

References 23 publications

Functionalized Unsaturated Polyester as Electrical Insulation Varnish

Functionalized Unsaturated Polyester as Electrical Insulation Varnish

Kinetic finite element model to optimize sulfur vulcanization: Application to extruded epdm weather‐strips

Effects of silica aerogel particle sizes on the thermal–mechanical properties of silica aerogel – unsaturated polyester composites

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