Thermal stability and degradation kinetics of poly(methyl methacrylate)/layered copper hydroxy methacrylate composites

Abstract

Abstract:Poly(methyl methacrylate) (PMMA)/copper hydroxy methacrylate (CHM) composites were prepared via solution blending and bulk polymerization. Addition of 3% by weight of the CHM additive using solution blending resulted in a significant increment (∼45°C) in thermogravimetric NOT THE PUBLISHED VERSION; this is the author's final, peer-reviewed manuscript. The published version may be accessed by following the link in the citation at the bottom of the page. Technology, Vol. 17, No. 4 (April 2006): pg. 312-319. DOI. This article is © Wiley and permission has been granted for this version to appear in e-Publications@Marquette. Wiley does not grant permission for this article to be further copied/distributed or hosted elsewhere without the express permission from Wiley. Polymers for Advanced2 analysis (TGA) T50, the temperature at which 50% of the original polymeric mass is lost. The value T50 increased by 30°C for a PMMA composite with 4% CHM, synthesized via bulk polymerization. Activation energies, Ea, were calculated as a function of conversion fractions (TGA decomposition profile) for the polymeric materials. Analysis of multiple heating rate data using the Flynn-Wall-Ozawa method resulted in Ea values that were 50 kJ mol −1 higher for conversions above 0.5 in the solution blended composite compared to a reference sample of pure PMMA recrystallized from the same solvent. Similar results were obtained for bulk polymerization process with differences in Ea values > 30 kJ mol −1 relative to pure PMMA. However, in contrast to previous studies of bulk polymerized samples, the solution-blended composite exhibited no improvement in cone calorimetry determination of total heat release as compared with the reference PMMA sample

The effect of boron-containing layered hydroxy salt (LHS) on the thermal stability and degradation kinetics of poly (methyl methacrylate)

“…Isoconversional methods do not suffer from that drawback and enables the determination of the dependency of Ea on the extent of reaction and are therefore favored over model-fitting methods [37], [38] and [39]. Both isothermal and non-isothermal methods have been used in the determination of kinetic parameters in the degradation of polymers [17], [29], [40], [41] and [42].…”

“…Recently another class of layered materials, anionic clays, have also generated interest as potential fire retardants and the most widely investigated materials in this class are the layered double hydroxide (LDH) [11] and [12]. LDHs are materials which are related to the mineral hydrotalcite and have a general formula which is represented as [M 2+ 1−xM 3+ x(OH)2]A n− x/n.yH2O, where M 2+ is a divalent Other closely related classes of anionic clays, hydroxy double salts (HDS) and layered hydroxy salts (LHS), although not extensively studied as LDH, have similarly been shown to have potential as fire retardants [17], [18] and [19]. In HDSs and LHSs, the metal hydroxide layers are composed of divalent cations represented as M 2+ and Me 2+ and are formulated as [M 2+ 1−x Me 2+ 1+x (OH)3(1−y)] x+ (A n− (1+3y)n)·m H2O.…”

Thermal Degradation of Acetate-Intercalated Hydroxy Double and Layered Hydroxy Salts

“…Previous work in our laboratory has shown that the addition of copper-containing HDSs or LHSs to poly(methyl methacrylate) 10,11 or poly(vinyl ester) 12,13 results in enhanced thermal stability. Significant reductions were observed in total heat release, as measured via cone calorimetry, and there was an increase in the amount of char formed compared with the virgin polymer.…”

“…The presence of reduced metallic species has been shown to play an important role in thermal stabilization of polymeric composites. [10][11][12][13]47,48 Klenov and co-workers 49 reported the appearance of Cu(I) and metallic copper on the surface of the Cu 2+ -containing ZnO after catalyst reduction and they believe these species play an important role in the catalytic synthesis of methanol from H2 and CO. The formation of reduced copper is thus important for enhancing selected chemical pathways.…”

Effect of Coal Ash on the Morphological, Thermal and Mechanical Properties of Poly(methyl Methacrylate)

“…The weight loss with third stage (about 360 o C) associated with random scission of the polymer backbone. 12 The TGA thermogram of the Ash (5 wt %)/ PMMA composite also presented three stage decomposition. The thermogram clearly indicated that the second and third stage of decomposition of the composite were shift to higher temperature as compared to pure PMMA.…”