Kinetic Study of Thermal Degradation of High-impact Polystyrene Nanocomposites with Different Flame Retardants using Isoconversional and Model Fitting Methods

Abstract

The non-isothermal degradation of pure high-impact polystyrene (HIPS) and flame retarded HIPS nanocomposites was investigated in the temperature range 25-550 °C at four heating rates in an inert atmosphere. Three different phosphate and polyphosphate based flame retardants were used, while nanosilica and montmorillonite clay were used as nanofillers. Kinetic analysis was performed using isoconversional and model fitting non-linear regression method. Activation energy (Ea) was determined by isoconversional methods of Friedman and KissingerAkahira-Sunose while true kinetic triplets (Ea, A, f(α)) were determined by one step and two-step non-linear regression with various reactions mechanisms. It was found that flame retarded samples exhibit complex degradation which cannot be satisfactorily described by single reaction model fitting. Instead, when each distinctive degradation step was modelled individually it was possible to obtain good fit with Reaction order and Avrami-Erofeev proposed mechanisms while the same was not possible for Diffusion and Autocatalytic mechanisms.

Kinetic Analysis of Poly(ε-caprolactone)/poly(lactic acid) Blends with Low-cost Natural Thermoplastic Starch

“…Because of the thermal degradation of individual polymers in the blends due to their intrinsic chemical reaction processes the investigation of their thermal properties and degradation kinetics of the decomposition is crucial for an accurate prediction of the materials behavior under different working conditions and as well as to optimize the process conditions. 15,16 In addition, thermal degradation of starch is important to conduct comprehensive studies on their thermal properties and stability of their application in food and pharmaceutical industries and to facilitate their use, since starch undergo thermal processes during their preparation, processing and consumption and on the other hand are poorly researched. 17 Thermogravimetry (TG) has proved to be reliable method which results can be used for determination of thermal stability of biopolymers and kinetic analysis.…”

“…17 Thermogravimetry (TG) has proved to be reliable method which results can be used for determination of thermal stability of biopolymers and kinetic analysis. 15,16 On the other hand, the goal of the kinetic analysis is to provide kinetic parameters of the degradation process, i.e. the activation energy (E), the pre-exponential factor (A) and a kinetic model (f(α)), the so called "kinetic triplet".…”