Three-dimensional cross-linking structures in ceramifiable EVA composites for improving self-supporting property and ceramifiable properties at high temperature

Ceramifiable EVA composite with three dimensional cross-linking structures was prepared by bis (tertbutylperoxy) diisopropyl benzene (BIPB) as cross-linking agent, and silicate glass frits (SGF) and ammonium polyphosphate (APP) were utilized as additives. By using FTIR, DSC and measurement of gel content, the formation of cross-linking structures was studied. Rheometer and TGA were used to characterize the rheological properties and thermal stability of the composite. The effect of cross-linking structures on the self-supporting property and the ceramifiable properties of the composite was investigated. The apparent porosity of the ceramic residues was examined. XRD and SEM were used for the phase composition and morphology of the ceramic residues analysis respectively. Results suggested that the cross-linking reaction occurred in the EVA matrix and the SGF and APP have no effect on the cross-linking reaction. The formation of cross-linking structures improved the rheological properties and thermal stability of the composite, resulting in the improvement on self-supporting and ceramifiable properties. Further, we demonstrated that cross-linking structures as "skeletal structures" could support its own weight before inorganic crystalline phases appeared, which provided a necessary prerequisite for its excellent self-supporting property in the range of 0-1000 degrees C. In addition, it has been proved that the apparent porosity was decreased and the compactness of ceramic residues was enhanced after the cross-linking structures were formed. (C) 2019 Elsevier Ltd. All rights reserved.