Influence of Zinc Oxide Addition on Azodicarbonamide Thermal Decomposition in the Polyethylene/Ethylene Vinyl Acetate Foaming Release

Abstract

Thermal properties, i.e. melting point and decomposition temperature of polymers, azodicarbonamide (ADC), and other additives mixture, are the most important information to determine the appropriate foaming process parameters. ADC has been widely used as a blowing agent for foam fabrication. Here, ADC will decompose and release gas which will be trapped in the melting polymer to make a foamed product. Originally, ADC has a decomposition temperature at around 220°C. In this study, the effect of Zinc Oxide (ZnO) addition on the thermal properties of intermediate product and Polyethylene/Ethylene Vinyl Acetate (PE/EVA) foam with ADC as the blowing agent was investigated. ZnO addition decreased the decomposition temperature of ADC. The thermal properties were characterized by Differential Scanning Calorimetry (DSC). The result showed that the decomposition temperature of ADC significantly decreased from the temperature of 220°C to 170°C with the increment of the ZnO.

Density Gradients, Cellular Structure and Thermal Conductivity of High-Density Polyethylene Foams by Different Amounts of Chemical Blowing Agent

“…Thermal decomposition of azodicarbonamide occurs at 210 °C without a catalyst and at 185 °C with 0.05% ZnO [ 19 , 20 ]. During decomposition, azodicarbonamide releases 25.4% of its weight as gases at 190 °C (N 2 71.9%, CO 26.3%, CO 2 1.4%, NH 3 0.4%), leaving 74.6% solid residues in the polymer [ 20 , 21 ]. For the production of high-density foams, it is sufficient to add 1–2 wt% of azodicarbonamide into the polymer [ 14 , 22 , 23 ].…”

The Out-Of-Plane Compression Behavior of In Situ Ethylene Vinyl Acetate (EVA)-Foam-Filled Aluminum Honeycomb Sandwich Structures

“…ZnO triggered an abrupt degradation of AZD at 175 • C, inducing a high heat flow and a high gas volume release (Figure 1d). In other words, ZnO decreases the activation energy for AZD decomposition [42]. The baseline slope of the DSC curve at temperatures above 150 • C could be related to the change in the AZD heat transfer due to the liberation of gaseous and degradation of the solid products [43].…”

Extrusion foaming of multiphasic polyethylene/ethylene-vinyl acetate copolymer/carbon nanotube mixtures: Tailoring foam properties by selective localization of nanoparticles

“…Thus, new materials having advantageous properties can be prepared using polymer blending techniques. 10,11 Accordingly, LDPE is typically blended with other polymers with more elastomeric behavior like poly(ethylene-co-vinyl acetate) (EVA). 12,13 The PE/EVA blend foams demonstrate better flexibility, higher toughness, more significant impact resistance, and lower thermal conductivity than LDPE foams.…”