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

Abstract

Abstract:A boron-containing layered hydroxy salt (LHS), ZHTMDBB, was prepared and compounded with a highly flammable synthetic polymer, poly (methyl methacrylate) {PMMA}, via melt blending: the composite structure was intercalated with poor dispersion. The effect of this LHS on the 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.Polymer Degradation and Stability, Vol. 95, No. 9 (September 2010): pg. 1593-1604. DOI. This article is © Elsevier and permission has been granted for this version to appear in e-Publications@Marquette. Elsevier does not grant permission for this article to be further copied/distributed or hosted elsewhere without the express permission from Elsevier. 2 flammability, thermal stability and degradation kinetics of PMMA was investigated via cone calorimetry and thermogravimetric analysis. The addition of 3-10% by mass of ZHTMDBB to PMMA resulted in significant reduction of peak heat release rate (22-48%) of the polymer and improvements in thermal stability were observed in both air and nitrogen. Effective activation energies for the degradation process were evaluated using Flynn-Wall-Ozawa, Friedman, and Kissinger methods. All three methods indicated that the additive increased the activation energies of the first step of the degradation process in both air and nitrogen. Activation energies of the second step were lowered in nitrogen but were not significantly affected in air.

Zinc layered hydroxide salts: intercalation and incorporation into low-density polyethylene

“…The diffraction pattern of the ZHN indicated the presence of a crystalline phase, with intense peaks related to the (200) and (400) planes. The basal spacing of the latter (monoclinic structure) was 9.66 Ȧ, similar to the value reported in the literature, 9.8 Å [21] . The LHS-DDS and LHS-DBS samples showed only one, low-crystallinity, phase.…”

Thermal and flammability study of polystyrene composites containing magnesium–aluminum layered double hydroxide (MgAl–C16 LDH), and an organophosphate

“…Figure 7 shows the residue remaining after cone calorimetry measurements of the composites. The LDH systems have a denser and compact residue that covers the whole aluminum foil with the top layer of the residue being white, we observed similar results in our previous work where the residue was in the form of pillars with the top layers being white and the bottom layer being black indicating that during the burning process, the inorganic residue formed a layer on top of the burning polymer which prevented further burning of the underneath polymer resulting in formation of carbonaceous char [44]. Neither the DPP systems nor the system with the combination of DPP and LDH leaves a compact residue after the cone calorimetry test, only tiny aggregates of residue scattered across the aluminum foil can be observed.…”

Morphology, mechanical properties and thermal degradation kinetics of PMMA-zirconia nanocomposites prepared by melt compounding

“…However, the differences between the two sets of values increase with increasing degree of conversion. The lower activation energy values for the nanocomposite at higher conversions may be related to strong interactions between zirconia and the free radicals formed during degradation, giving rise to the nanoparticles having a catalytic effect on the PMMA degradation during the more advanced stages of degradation [22,23]. TGA-FTIR analyses were done to establish the nature of the degradation product(s), and to confirm the observations from the kinetic analysis of the thermal degradation of PMMA and PMMA-zirconia (5!wt%).…”