Pyro-GC/MS and thermal degradation studies in polystyrene–poly(vinyl chloride) blends

Limitations of model-fitting methods for kinetic analysis: Polystyrene thermal degradation

“…A lack of plot linearity and inconsistent activation energy values are observed and the authors conclude that simple first or second order models are good enough for determining the activation energy and, therefore, constitute "the most suitable design approach". Other works employing similar single-curve model-fitting kinetic procedures reached analogous conclusions (Ahmad et al , 2010, Ahmed and Gupta, 2009, Krishna and Pugazhenthi, 2011. However, some other works, employing isoconversional and non-linear model fitting methods, have revealed the unsuitability of nth order reaction models and suggest an acceleratory model instead (Chen et al , 2007, Sanchez-Jimenez et al , 2010, Snegirev et al , 2012, Vyazovkin et al , 2004.…”

Principles of Thermal Degradation

“…319 Figure 4.58 shows the effect of addition of PS on thermal stability of PVC blend. 321 Also, reduction in pyrolysis products was observed. 316 The influence of PS on thermal stability of PVC is explained by diffusion of HCl into PS phase (removal of catalyst from PVC) and lowering polarity, which also decreases the rate of HCl loss.…”

“…It is speculated that the improvement of PVC thermal stability is caused by absorption of HCl into polysiloxane phase which reduces its catalytic influence on PVC thermal degradation. 321 The stabilization effect on PS depends on the heating rate and the blend composition. PS decreases PVC dehydrochlorination more extensively as would be expected from dilution of degrading polymer (PVC).…”

The kinetics of typical medical waste pyrolysis based on gaseous evolution behaviour in a micro-fluidised bed reactor

“…The above results indicate that the gases are formed via different chemical routes or mechanisms during medical waste pyrolysis. Ahmad et al (2010) reported that polystyrene was first decomposed to benzene, toluene and styrene at a higher temperature, and then formed hydrocarbon by the secondary reactions, such as cracking, H-atom abstraction, H-atom attack and ipso-substitution (Gai et al, 2015; Ozsin and Putun, 2017; Yuan et al, 2015). H 2 is generally formed by the radical polycondensation and dehydrogenation reactions, which is also favoured at higher temperature (Han et al, 2017e; Yu et al, 2011).…”

“…Thermogravimetric analysis (TGA) has been widely used to study the thermal degradation kinetics of carbon-based materials based on monitoring the mass variation of a spot sample under a specified heating programme (Han et al, 2017a; Han et al, 2017c; Ozsin and Putun, 2017; Snegirev et al, 2012). Most of the activation energy of plastic pyrolysis ranged from 100 to 300 kJ mol −1 (Ahmad et al, 2010; Chen et al, 2007; Deng et al, 2008; Yan et al, 2009). Nonetheless, there are still some drawbacks during the thermal degradation kinetics parameters obtained by using a TGA.…”