DSC-TG studies on kinetics of curing and thermal decomposition of epoxy–ether amine systems

Supriya, N.; Catherine, Korah Bina; Ramanan, Rajeev

doi:10.1007/s10973-012-2805-5

Cited by 21 publications

(4 citation statements)

References 24 publications

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“…In general, for a single step polymerization, the E a is constant for all a which is different from a multi-step polymerization [20,21]. The differential method (Friedman) and the integrated methods ((KAS) and (FWO)) were used in this work to investigate the dependence of E a with a [44,45]. These three methods were applied to non-isothermal kinetic data to determine E a from the ROP of e-CL initiated by a selected initiator concentration (1.0 mol%).…”

Section: Isoconversional Kinetic Analysismentioning

confidence: 99%

Kinetics and thermodynamics analysis for ring-opening polymerization of ε-caprolactone initiated by tributyltin n-butoxide using differential scanning calorimetry

Limwanich

Meepowpan

Nalampang

et al. 2014

J Therm Anal Calorim

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The bulk ring-opening polymerizations (ROP) of e-caprolactone (e-CL) initiated by synthesized tributyltin n-butoxide (nBu 3 SnOnBu) initiator were conducted at 120°C and the molecular mass and polydispersity index of poly(e-CL), PCL, were determined. The coordinationinsertion ROP of e-CL was confirmed by 1 H-NMR. The molecular mass of PCL was successfully controlled with monomer to initiator concentration ratio. The kinetics and thermodynamics of ROP were investigated by differential scanning calorimetry (DSC) using both non-isothermal and isothermal methods. From the non-isothermal method, the activation energy (E a ) of ROP of e-CL initiated by 1.0, 1.5, and 2.0 mol% of nBu 3 SnOnBu was derived from the method of Kissinger (78.3, 61.1, and 59.9 kJ mol -1 ) and Ozawa (82.8, 66.2, and 64.9 kJ mol -1 ). For isothermal method, the values of E a for these three concentrations of nBu 3 SnOnBu were 74.2, 65.8, and 62.0 kJ mol -1 , respectively. The first-order reaction model was employed to determine the apparent rate constant (k app ). The degree of aggregation (m) of nBu 3 SnOnBu in e-CL was also determined using isothermal method which confirmed its nonaggregated form. In addition, the activation enthalpy (DH = ) and entropy (DS = ) were estimated to be 70.5 kJ mol -1 and -100.3 J mol -1 K -1 by isothermal DSC. The Friedman, Kissinger-Akahira-Sunose, and Flynn-Wall-Ozawa isoconversional methods were also applied to non-isothemal DSC data to investigate the dependence of E a with monomer conversion (a). The results of all three methods were discussed and compared with isothermal and non-isothermal methods at 1.0 mol% of nBu 3 SnOnBu. The overall results demonstrate that DSC is a fast, convenient, and reliable method for studying the kinetics and thermodynamics of ROP of e-CL initiated by nBu 3 SnOnBu.

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Section: Isoconversional Kinetic Analysismentioning

confidence: 99%

Kinetics and thermodynamics analysis for ring-opening polymerization of ε-caprolactone initiated by tributyltin n-butoxide using differential scanning calorimetry

Limwanich

Meepowpan

Nalampang

et al. 2014

J Therm Anal Calorim

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“…Te reaction equations are shown in Equations ( 4) and (5). Te occurrence of diferent phases may be related to the heating rate [50,51]. Te cracking phenomenon was more apparent at 525 °C than at 470 °C, indicating that the degree of reaction at 525 °C was higher than that at 470 °C and that the maximum amount of gaseous products was produced at that temperature.…”

Section: Characteristics Of Solid Products From Iron Sulfde Minerals ...mentioning

confidence: 99%

Effects of Pyrrhotite on the Combustion Behavior and the Kinetic Mechanism of Pyrite-Pyrrhotite Mixture Powders in the Air

Tian

Rao

et al. 2023

International Journal of Chemical Engineering

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In this study, we performed a comparative analysis of the combustion behavior of pyrite, pyrrhotite, and pyrite-pyrrhotite mixture (mixed mineral) powders in an air atmosphere. To study the influence of the pyrrhotite content in mixed mineral powders on the combustion behavior in the air, thermogravimetric mass spectrometry, X-ray diffraction analysis, and scanning electron microscopy were employed. The results indicated that pyrrhotite lead to a weight gain in the mixed minerals during the combustion process. Pyrrhotite particles are more easily adsorbed on the surface of pyrite particles during mixed mineral combustion due to their strong ability to absorb oxygen, which accelerates pyrite combustion. The weight loss of mixed minerals decreased during the combustion process with increasing pyrrhotite content, resulting from pyrite encapsulation by agglomerated and sintered pyrrhotite during combustion. The calculated kinetic parameters and phase analysis results suggested that pyrite combustion is consistent with the shrinking core mechanism, and in the combustion process, the irregular pyrite particle shrank into a spherical particle; the combustion products of pyrrhotite grew in a layer-by-layer manner. Pyrrhotite combustion corresponded to the three-dimensional diffusion mechanism, and mixed mineral combustion was dominated by the shrinking core mechanism and supplemented by the three-dimensional diffusion mechanism. SO2, as the main combustion product, was continuously generated and volatilized in the reaction, signifying that the combustion reaction of pyrite is a two-phase reaction involving gas and solid.

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“…Under the vacuum and heat environment of the outgassing test, the lower degree of curing of the EP-EPOSS samples causes the release of molecular fragments that are not fully polymerized. This process is promoted by the increased presence of ether linkages in the EP-EPOSS polymer, which leads to an increase of the chain mobility and as a result, reduction in the T g values [51,60,61]. As a result, uncured molecules can diffuse more easily from the bulk to the surface and outgas, resulting in higher TML and RML values [62].…”

Section: Outgassing Propertiesmentioning

confidence: 99%

Influence of POSS Type on the Space Environment Durability of Epoxy-POSS Nanocomposites

Bram

Gouzman²,

Bolker³

et al. 2022

Nanomaterials

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In order to use polymers at low Earth orbit (LEO) environment, they must be protected against atomic oxygen (AO) erosion. A promising protection strategy is to incorporate polyhedral oligomeric silsesquioxane (POSS) molecules into the polymer backbone. In this study, the space durability of epoxy-POSS (EPOSS) nanocomposites was investigated. Two types of POSS molecules were incorporated separately—amine-based and epoxy-based. The outgassing properties of the EPOSS, in terms of total mass loss, collected volatile condensable material, and water vapor regain were measured as a function of POSS type and content. The AO durability was studied using a ground-based AO simulation system. Surface compositions of EPOSS were studied using high-resolution scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that with respect to the outgassing properties, only some of the EPOSS compositions were suitable for the ultrahigh vacuum space environment, and that the POSS type and content had a strong effect on their outgassing properties. Regardless of the POSS type being used, the AO durability improved significantly. This improvement is attributed to the formation of a self-passivated AO durable SiO2 layer, and demonstrates the potential use of EPOSS as a qualified nanocomposite for space applications.

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DSC-TG studies on kinetics of curing and thermal decomposition of epoxy–ether amine systems

Cited by 21 publications

References 24 publications

Kinetics and thermodynamics analysis for ring-opening polymerization of ε-caprolactone initiated by tributyltin n-butoxide using differential scanning calorimetry

Kinetics and thermodynamics analysis for ring-opening polymerization of ε-caprolactone initiated by tributyltin n-butoxide using differential scanning calorimetry

Effects of Pyrrhotite on the Combustion Behavior and the Kinetic Mechanism of Pyrite-Pyrrhotite Mixture Powders in the Air

Influence of POSS Type on the Space Environment Durability of Epoxy-POSS Nanocomposites

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