Evolved gas analysis of PEP-SET sand by TG and FTIR.

Thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TG-FTIR) and on-line FTIR were employed in this study, aiming at investigating the pyrolysis characteristic of Polybenzylic Ether Phenolic resin sand mould (PEP-SET sand) and emission gases generated during casting. The non-isothermal pyrolysis of PEP-SET sand can be subdivided into three stages: emission of inherent moisture (below 215 °C), thermal decomposition at low temperature (215–315 °C) and further cracking process at high temperature (315–432 °C). The main emission gaseous products in pyrolysis processes were H 2 O, CO 2 , NH 3 , CH 4 , C 2 H 6 , NO and a little amount of CO, according to the FTIR spectrum analyses. The amount of N-containing pyrolysis products generated from cracking of the C N bond reflects the collapse extent of the binder. The thermal shock tests at different temperatures were performed. Similar to non-isothermal pyrolysis processes, the main gaseous products were CO 2 , CO, NO, CH 4 and C 2 H 6 under thermal shock conditions, and these gases released follow a fixed sequence: concentrations of CO, CO 2 and NO firstly increased to the peaks and then decreased with the rising of CH 4 and C 2 H 6 . At last the CO 2 concentration increased again. The major emission oxidizing gas which may induce ignition of Mg melt is CO 2 and the environmental hazardous components are NO and NH 3 . [ABSTRACT FROM AUTHOR]