Main Degradation Stage Research Articles

Fe2O3, Al2O3, or sludge ash-catalyzed pyrolysis of typical 3D printing waste toward tackling plastic pollution

Catalytic pyrolysis offers a potential solution to tackling plastic pollution by transforming plastic waste into valuable chemicals. This study explored the catalytic pyrolysis of 3D printing waste (3DPW), specifically focusing on photosensitive resin waste (PRW) and polycaprolactone waste (PCLW), with Al2O3, Fe2O3, or sludge ash (SA) containing Fe/Al. The study revealed a synergistic effect between the catalyst and 3DPW, influencing the pyrolysis properties and kinetic models. The addition of Fe2O3 significantly accelerated the main degradation stages, promoting the releases of 2-Ethylacrolein (64.78 % from PRW) and 2-Oxepanone (16.45 % from PCLW), as well as decreasing the acidic products. The catalytic pyrolysis changed the valence state of Fe, with some Fe(III) shifting to Fe(II), accompanied by the release of CO2. The addition of Al2O3 or SA generated new gaseous products (e.g., 2.93 % 1,3-Pentadiene, 2-methyl-, (E)-) through volatile reforming. The joint optimization of the multi-response artificial neural network revealed PCLW/Fe2O3 between 325–399 °C (D = 0.669) as the optimal operation for achieving both minimal remaining mass and maximum decomposition rate. These findings offer actionable insights into the catalytic pyrolysis of 3DPW, promoting its efficient treatment and clean reutilization.

Synthesis, Characterization, Thermal Stability, and Kinetic Degradation of Cellulose p‐Halide Benzoates in an Ionic Liquid 1‐Butyl‐3‐methylimidazolium Chloride

AbstractCellulose p‐halide benzoates (C‐p‐HB) were synthesized by reacting microcrystalline cellulose (MCC) with p‐halide benzoyl chloride (p‐HBCl) namely; the p‐Iodobenzoyl chloride (p‐IBCl), p‐Bromobenzyl chloride (p‐BBCl), and p‐Nitrobenzoyl chloride( p‐NBCl) in ionic liquid 1‐butyl‐3‐methylimidazolium chloride [Bmim](Cl) at 60 °C for 2 h in the presence of 4‐dimethylaminopyridine (DMAP) as a base. The synthetic products were characterized through infrared spectrometry (FT‐IR), nuclear magnetic resonance (NMR) spectroscopy, XRD, and scanning electron microscopy (SEM). Then, the effects of p‐halide benzoate groups on the thermal degradation of C‐p‐HB esters with DS≈1 were investigated using thermogravimetric analysis under an inert atmosphere from room temperature to 600 °C at a heating rate of 5 °C/min. The DSC analysis was used to determine the glass temperature and heat of the reaction of C‐p‐HB esters. The results indicated that the C‐p‐HB was successfully synthesized in [Bmim](Cl) with a DS≈1. The kinetic parameters were determined by the Coats‐Redfern (CR) method. The corresponding kinetic parameters of the main degradation stages were also determined. The thermal stability of MCC was remarkably decreased through esterification with p‐HBCl. The Criado method was used to determine the most probable degradation functions. Thus, reaction orders F2 and F3 were most probably the functions that describe the degradation of C‐p‐HB.

Biotechnological investigation of Pediastrum boryanum and Desmodesmus subspicatus microalgae species for a potential application in bioenergy

The production of photosynthetic microalgae is a promising ecological advantage for obtaining carbon credits. This paper addresses cultivation and preparation, growth analysis, physicochemical characterization (X-ray diffraction-XRD, Fourier transform infrared-FTIR, scanning electron microscopy-SEM, and energy dispersive spectroscopy-EDS), and thermal behavior (thermogravimetry-TG, derivative thermogravimetry-DTG, and differential scanning calorimetry-DSC) of two microalgae, namely Pediastrum boryanum-PB (CH007) and Desmodesmus subspicatus-DS (AEE431E) for a potential application as an energy resource. Regarding the former, the literature reports no specific study on the species, which shows high lipid productivity and fast growth. A synthetic culture medium (Walter culture-WC) was subjected to variations in pH, luminosity, and maximum growth reached in 12 and 13 days for PB and DS, respectively. TG/DTG curves identified the main thermal degradation stages, i.e., dehydration (DS (24.68–158.68 °C) and PB (20.06–116.18 °C)), devolatilization (DS (166.34–543.00 °C) and PB (128.22–493.93 °C)), and gasification or carbonization (DS (>550 °C) and PB (>500 °C)), and DSC curves revealed two endothermic events, an exothermic one for DS, and only one endothermic event and an exothermic one for PB. XRD patterns showed a cellulose crystallinity index (CI) for DS (22.54 %) and PB (28.82 %), confirming the predominance of amorphous regions. SEM images detected external epidermis for DS and some interconnected pores for PB. The FTIR spectra identified functional groups (lipids, proteins, and carbohydrates) and CO, CO, OH, CH, and C-O-C linkages, and EDS and ICP-OES identified the main organic, inorganic, and metallic elements. The microalgae species displayed characteristics similar to those of the other biomasses in the bioenergy industry, enabling their use in thermoconversion processes for biofuel production and considering some socioenvironmental aspects.

Actionable insights into hazard mitigation of typical 3D printing waste via pyrolysis

3D printing waste (3DPW) contains hazardous substances, such as photosensitizers and pigments, and may cause environmental pollution when improperly disposed of. Pyrolysis treatment can reduce hazards and turn waste into useful resources. This study coupled thermogravimetric (TG), TG-Fourier transform infrared spectroscopy-gas chromatography/mass spectrometry, and rapid pyrolysis gas chromatography/mass spectrometry analysis to evaluate the pyrolytic reaction mechanisms, products, and possible decomposition pathways of the three typical 3DPW of photosensitive resin waste (PRW), polyamide waste (PAW), and polycaprolactone waste (PCLW). The main degradation stages of the typical 3DPW occurred at 320–580 °C. The most appropriate reaction mechanisms of PRW, PAW and PCLW were D1, A1.2 and A1.5, respectively. The main pyrolysis processes were the decomposition of the complex organic polymers of PRW, the breaking of the NH–CH2 bond and dehydration of –CO–NH– of PAW, and the breaking and reorganization of the molecular chains of PCLW, mainly resulting in toluene (C7H8), undecylenitrile (C11H21N), tetrahydrofuran (C4H8O), respectively. Unlike the slow pyrolysis, the rapid pyrolysis produced volatiles consisting mainly of phenol, 4,4'-(1-methylethylidene)bis- (C15H16O2) for PRW; 1,10-dicyanodecane (C12H20N2) for PAW; and ɛ-caprolactone (C6H10O2) for PCLW. These pyrolysis products hold great potential for applications. The findings of the study offer actionable insights into the hazard reduction and resource recovery of 3D printing waste.

Characterization of Ash from Sugar Palm [Arenga Pinnata (Wrumb) Merr.] Fiber for Industrial Application

ABSTRACT Sugar palm (Arenga Pinnata) fiber is abundant in Malaysia which necessitates its utilization as a source of agricultural waste for industrial development. This paper aims at characterizing the sugar palm fiber to explore its silica content as a potential renewable material. The sugar palm fiber was carbonized, and the ash obtained was characterized via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), energy dispersive spectroscopy (EDS) and field emission scanning electron microscope (FESESM). The presence of amorphous silica (SiO2) with an average particle size of 41.25 nm was revealed by X-ray diffraction. Fourier transform infrared spectroscopy indicated the presence of functional groups such as silane and siloxane groups, and thermogravimetric analysis and differential scanning calorimetry identified the main degradation stages of the sugar palm fiber ash, and the decomposition of hemicellulose, lignin, cellulose, and carbonate to other oxides. The energy dispersive spectroscopy of the sugar palm fiber ash confirmed silica to be of the highest amount than other elements. Sugar palm fiber ash has been found as a possible silica substitute and a prospective industrial resource.

COMPARISON OF PROPERTIES OF CELLULOSE NANOMATERIALS OBTAINED FROM SUNFLOWER STALKS

This study aimed to investigate the usability of sunflower stalks, which is one of the most significant agricultural residues in Turkey, in the production of cellulose nanomaterials (CNMs). Cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs) were produced by using a grinding method and acid hydrolysis, respectively. The average width and length of CNCs were found as 13.91 ± 3.09 nm and 60.44 ± 21.06 nm, respectively. Besides, the average width of CNFs was determined as 15.03 ± 3.68 nm. The crystallinity index of CNFs and CNCs was determined as 82.64% and 83.09%, respectively. Although the main thermal degradation stage of CNCs started at higher temperature than that of CNFs, the latter were more stable than CNCs at high temperatures. Furthermore, the chemical bonds in the raw material, bleached fiber, CNCs and CNFs were investigated with FTIR analysis. Consequently, it was seen that sunflower stalks can be a suitable raw material for the production of CNMs.

Preparation and pyrolysis kinetics of melamine phytates/rigid polyurethane foam composites

A series of melamine phytates/rigid polyurethane foam (MEL-PA/RPUF) composites were prepared by one-step water-blown method with MEL-PA as flame retardant. Thermogravimetric analysis (TG) and thermal analysis kinetics were used to study the thermal stability of the composites and reveal its degradation mechanism. The results show that the char residues of MEL-PA/RPUF gradually increases at 700℃ with the increase of MEL-PA loading. Based on TGA data, the reaction grade n, activation energy E and pre exponential factor A of the main degradation stage for the composites were calculated by the Coats-Redfern and Horowitz-Metzger integration methods. The results show that MEL-PA promotes the initial degradation of the composites in air atmosphere, while the MEL-PA/RPUF composites have higher thermal stability in the high temperature stage, and the two calculation methods have the same law. In N2 atmosphere, MEL-PA30/RPUF (mass fraction of MEL-PA is 10.3wt%) has higher n and E compared with RPUF. The results indicate that the reaction of MEL-PA30/RPUF is more complex and the thermal stability is higher. The mathematical model and experimental analysis by Criado method verify the feasibility of the Coats-Redfern method. The results of thermal degradation kinetics of MEL-PA/RPUF composites provide reference for the analysis of flame retardation performance of RPUF with different flame retardation systems.

Synthesis, Characterization and Pyrolysis Kinetics of Chitosan-N-Phenylacetamide in an Ionic Liquid 1-Butyl-3-Methylimidazolium Chloride

This study intends to synthesis novel compound phenolic chitosan-based via reaction of chitosan with 2-Chloro-N-phenylacetamide in 1-butyl-3-methylimidazolium chloride ionic liquid in the presence of pyridine at 80 °C for 4 h. The alterations in the chemical structure and morphology of the chitosan-N-phenylacetamide biopolymer were verified using IR spectroscopy, XRD, and SEM analyses. Chitosan and Chitosan-N-phenyacetamide were subjected to thermo-gravimetric analysis under an inert atmosphere in the temperature range of room temperature - 600 °C at a heating rate of 20 °C.min-1. The kinetic parameters were determined by the Coats-Redfern method. The corresponding kinetic parameters of the main degradation stages were also determined. The energy required for the degradation of pure chitosan was lower than that of chitosan-N-phenylacetamide in the first region of thermal degradation where the main pyrolysis reaction took place, and the largest weight loss occurred. Energy values in this region are running from 40.25 to 151.07 kJ/mol and 58.45 to 210.99 kJ/mol, respectively. The most probable reaction functions have thus been determined for these two stages by Coats-Redfern and Criado method, leading to greatly improved calculation performance over the entire conversion range. The pyrolysis reaction models of both pure chitosan and chitosan-N-phenylacetamide are described by the reaction, second-order F2.

TG-FTIR and Py-GC/MS study of the pyrolysis mechanism and composition of volatiles from flash pyrolysis of PVC

To facilitate the reuse and recycling of polyvinyl chloride (PVC) to achieve sustainable development and new industrialization, the composition and mechanism of formation of volatiles during the flash pyrolysis of PVC were studied by thermogravimetry-Fourier transform infrared (TG-FTIR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). TG and derivative thermogravimetry (DTG) analyses indicated two main degradation stages during flash pyrolysis of PVC, namely dehydrochlorination of PVC and decomposition of dechlorinated-PVC. Simultaneously, the FTIR results revealed that the main functional groups in the pyrolysis process were H–Cl, -C-Cl, C–H, CH, and aromatic groups. The relative content of main volatiles was determined by Py-GC/MS, and decreased in the following order: aromatics > alkenes > hydrogen chloride (HCl) > chlorinated hydrocarbons. Specifically, the relative content of aromatics was as high as 76.790–81.809%, while that of HCl was in the range of 3.016–3.096%. The carbon number distribution and the relative content of main products obtained from the flash pyrolysis of PVC at different final temperatures were also analysed. According to the experimental results, the mechanism of formation of the main volatiles based on free-radical reactions was deduced in detail. Therefore, this study provides further details for deepening the understanding of the PVC pyrolysis process.

Physical–chemical characterization and thermal behavior of cassava harvest waste for application in thermochemical processes

Bioenergy generation from agroindustrial wastes has been investigated worldwide because of rising fossil fuel prices and the requirements of environmental legislation to reduce greenhouse gas emissions. In this research, the thermal behavior of cassava harvest wastes (husks, stalks, leaves) was investigated under two atmospheres: combustion (oxidizing) and pyrolysis (inert) by thermal analysis (TG/DTG curves). Other analytical techniques, such as X-ray diffraction, proximate and ultimate analyses, calorimetric analysis (HHV/LHV), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), energy-dispersive spectroscopy (EDS), and inductively coupled plasma optical emission spectrometry (ICP-OES), were also applied to characterize them. The TG/DTG curves identified the main thermal degradation stages of the lignocellulosic materials, which correspond to average contents of hemicellulose (49.1%), cellulose (31.7%), lignin (16.2%), moisture (10.0%), ash (6.3%), volatile materials (68.0%), and fixed carbon (16.0%). X-rays showed a crystallinity index for the biomasses between 53.0 and 60.0%, confirming crystalline and amorphous regions. Metal composition determination by ICP-OES identified the main metallic and inorganic materials (K, Ca, Al, and Fe) present in the samples. SEM images revealed some morphological and structural differences, for example pores, roughness, fibers, and lamellae. FTIR was used mainly to evaluate the presence of energy bands or oxygen, carbon, and hydrogen bonds, confirming the data obtained by the ultimate analysis. EDS identified the behavior of the main organic and inorganic elements. All the results presented demonstrate the importance of this research and its application to science.

Synthesis, characterization and thermokinetic analysis of the novel sugar based styrene co-polymer

Abstract A new α-chloralose (1,2-O-(R)-trichloroethylidene-α-D-glucofuranose)-based copolymer of styrene (PSVTEG) (2) was synthesized from vinyl (hydroxyl) furan monomer (1) and styrene by a conventional free radical polymerization reaction. The thermal decomposition kinetics of polymer were investigated by means of thermogravimetric analysis in dynamic nitrogen atmosphere at different heating rates. The apparent activation energy for the main stage thermal decomposition of the copolymer PSVTEG (2) was calculated using the Flynn-Wall-Ozawa and found to be 159.0±3 kj/mol. In addition, the activation energy value was calculated according to Coats-Redfern method and found to be compatible with the obtained result. The thermogram of the glycopolymer (PSVTEG) (2) has two decomposition stages and the calculated activation energy indicated that the main degradation stage is a nonspontaneous process (integral form 1/(1−α)2 for F3).

Enhancing thermal oxidation and fire resistance of reduced graphene oxide by phosphorus and nitrogen co-doping: Mechanism and kinetic analysis

The use of reduced graphene oxide (rGO) in high-temperature oxidization (HTO) environment, is limited by its poor thermal oxidation and fire resistance. In this study phosphorus and nitrogen co-doped reduced graphene oxide (PN-rGO) with high oxidation and fire resistance was prepared by hydrothermal and microwave treatment and its thermal oxidation decomposition kinetics and mechanisms were analyzed. Concisely, PN-rGO presents an increment of 162 °C in the decomposition temperature relative to undoped rGO (WrGO), and excellent fire resistance with only a ∼20% mass loss after burning. Thermal oxidation degradation kinetics reveals that WrGO shows continuously increasing activation energy (E) within a range of 119.7–182.9 kJ/mol, while PN-rGO exhibits almost constant E of ∼171.8 kJ/mol during main degradation stage. Moreover, the improved E at initial stage by phosphorus/nitrogen doping, combining with the char analysis, suggested that the introduction of strong chemical bonds replacing the reactive oxygen-containing groups was the key to preventing the oxidation of rGO. As one of the main properties, the electrical conductivity of PN-rGO is well kept after HTO treatment. This work demonstrates that a doping strategy can effectively expand the application of graphene-based devices in HTO environment.

Effects of the ultrasound-assisted pretreatments using borax and sodium hydroxide on the physicochemical properties of Chinese fir

This work investigated the physicochemical properties of Chinese fir after ultrasound-assisted pretreatments with borax and sodium hydroxide additives in an aqueous solution. TGA, FTIR, and XRD were used to analyze the thermal degradation processes, changes in chemical structures, and crystallinity of the treated samples, respectively. Additionally, the release of volatiles from wood pyrolysis was measured on-line by the TG-FTIR apparatus. In thermal analysis, all samples showed main degradation stages at 220–500 °C, and alkaline compounds could efficiently shift the process to lower temperatures with lower maximum weight loss rate (MWLR) and more residues. From TG-FTIR, it was observed that CO2 was the primary gas product from pyrolysis in the alkaline-treated samples, while there were more carbonyl compounds released in the control and deionized water groups. Due to the destruction and removal of hemicellulose and lignin after alkaline treatments, the related peaks changed greatly. Changes in the ester groups caused by saponification also accounted for one of the most significant differences between samples. Moreover, except for the deionized water group without sonication, the crystallinity of the samples increased from 6.34% to 11.29%. Overall, comparing the samples treated with or without ultrasound, the results showed that the ultrasound treatment did influence the samples’ physicochemical properties, and its’ effects varied by the basicity of the solution. This in-depth investigation offers a better understanding of ultrasound-assisted and alkaline pretreatments of wood materials.

Characterization of the complexing agents’ influence on bioscouring cotton fabrics by FT-IR and TG/DTG/DTA analysis

The nature of the complexing agents used in the bioscouring process of cotton fabrics aiming to eliminate the non-cellulosic compounds (pectin, waxes, etc.) and to improve the hydrophilic and wetting properties influences the thermal behaviour and the FT-IR spectra of the textile materials. In this paper, we study the influence of the experimental conditions and complexing agent nature (sodium citrate or disodium EDTA salt) on the pectin elimination in bioscouring treatment of cotton fabric by FT-IR and TG/DTG/DTA analysis. The changes from FT-IR spectra of the specific bands (absorbance intensity at 2916, 2852, 1732 and 1640/1642 cm−1) were evaluated. The thermal behaviour of the investigated samples’ fabric by using TG/DTG/DTA analysis was studied at 30–600 °C temperature range, in air atmosphere. All samples showed three mass-loss steps due to the elimination of humidity, decomposition of the non-cellulosic and cellulosic components (main degradation stage of the samples) and thermo-oxidative decomposition of the formed degradation products. The Tonset values corresponding to the main decomposition step, the mass-loss values (%Δm) and the % residual mass (at 600 °C) were influenced by the complexing agent nature as well as the concentration and the action time of the commercial enzyme product. In addition, the calcium content of some samples treated with and without ultrasound was determined using atomic absorption spectroscopy method (AAS) in order to correlate the results with TG/DTG/DTA analysis. The obtained results have shown that the synergistic action of experimental conditions (enzyme concentration, pH, enzyme product action time, ultrasound) and the presence of sodium citrate as a biodegradable complexing agent led to the elimination of a higher amount of pectin from the cotton samples than that eliminated when using EDTA.

An investigation of pollen grain thermal diversity on species level

In the current study, the thermal stability of four selected Pinus L. species was analyzed in order to test the hypothesis that wethers pollen grain from same genus exhibit any variation on the species level. For this purpose Pinus sylvestris L., Pinus brutia Ten., and Pinus nigra Arn. were subjected to dynamic thermogravimetric analysis. The obtained thermograms the selected four Pinus species revealed no significant variation among their thermograms. For all the tested species five main degradation stages have been observed. The dTGmax values for P. griffithii Mc. Clelland, P. sylvestris, P. nigra and P. brutia were recorded at 442.6 °C, 439.1 °C, 442.2 °C, and 437.6 °C respectively. Considering the results from the current study it can be clearly concluded that the thermal stability of pollen grains from the same genus do not exhibit any significant variation

Kinetic study of thermal degradation of chitosan as a function of deacetylation degree

Thermal degradation of chitosan with varying deacetylation degree (DD) ranging between 50 and 85% was analyzed by dynamic thermogravimetric analysis at different heating rates. The present study focused on the temperature range between 500 and 800K, above water evaporation. Thermal degradation showed a main degradation stage in this temperature interval with a second stage that appeared in the weight derivative curves as a shoulder in the high temperature side of the main peak with increasing intensity as the DD decreased. The Kissinger and isoconversional Ozawa-Flynn-Wall models were employed to evaluate the Ea of both thermal degradation processes. Different kinetic models were tested to computer simulate the thermogravimetric traces calculating the model parameters with a non-linear least squares fitting routine. The Sestack-Berggren model allowed reproducing accurately the overlapping of the two degradation mechanisms and calculating the mass fraction lost in each of them revealing the coupling between the two degradation mechanisms.

Solvolysis kinetics of three components of biomass using polyhydric alcohols as solvents

The solvolysis behavior and reaction kinetics of the three components of biomass (cellulose, hemicelluloses and lignin) liquefied in polyhydric alcohols (PEG 400 or glycerol) were investigated in this paper. Three stages were observed during the solvolysis process and the main degradation stage could be further divided into two zones. The influences of solvents on the liquefaction process of three main components were compared. Based on Starink and Malek methods, kinetic parameters and mechanism functions were obtained. The derived average activation energy of cellulose, hemicellulose and lignin were 108.73, 95.66 and 94.13kJmol−1 in PEG 400, while the values were 102.16, 77.43 and 89.10kJmol−1 in glycerol, respectively. Higher efficiency was observed when using glycerol as solvent, which could be ascribed to the higher polarity value of glycerol. The conversion curves calculated with obtained mechanism models and kinetic parameters were in good agreement with the experimental data.

Thermal properties and thermal degradation kinetics of phenolic and wood flour-reinforced phenolic foams

In the present work, the thermal stability, changes in chemical structure during thermal degradation, and the kinetics of thermal degradation of a phenolic foam were studied. An 8.5 wt% of Pinus radiata wood flour reinforcement was added to the phenolic foam. A commercial phenolic resol was used as the matrix for the foam. The wood flour-reinforced foam showed a structure similar to the phenolic foam according to the Fourier transform infrared spectroscopy results. The wood flour increased the thermal stability of the phenolic foam in the first stage of thermal degradation ( T5%), decreased it in the second step ( T25%), and negligibly influenced the final stage. The activation energies of the degradation processes of the studied materials were obtained by the Kissinger-Akahira-Sunose and Flynn-Wall-Ozawa model-free kinetic methods and a 2-Gaussian distributed activation energy model. The values of the activation energies obtained by the model-free kinetic methods for the first degradation stage of the phenolic foams were in a range between 110 and 170 kJ mol−1, whereas for the wood flour it was 162 kJ mol−1for almost all of the conversion range of its main degradation stage. The applied models showed good fits for all the materials, and the activation energies calculated were in agreement with the values found in the literature.

The Synthesis of Allyl Glycidyl Ether Copolymers and Their Thermokinetic Analysis

Abstract The copolymerization reactions of allyl glycidyl ether (AGE) by radicalic polymerization under argon atmosphere using benzoyl peroxide (BPO) as an initiator with the comonomers of allyl methacrylate (AMA) and methyl methacrylate (MMA) were studied. The synthesized copolymers were characterized by nuclear magnetic resonance ( 1 H-NMR), gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TG). FTIR and 1 H NMR spectra showed that the pendant epoxy groups in copolymers remained throughout the copolymerization of AGE. The apparent activation energies for thermal degradation of the copolymers were calculated from their TG data by using Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS) and Coats-Redfern methods. The kinetic parameters such as pre-exponential factor, Gibbs energy, enthalpy and entropy were also calculated by Coats-Redfern method. The activation energies calculated by KAS method for Poly(AGE -co- AMA) and Poly(AGE -co- MMA) were found to be 292±10 kJ/mol and 175±27 kJ/mol for the first stage, and 252±74 kJ/mol and 232±32 kJ/mol for the second, respectively while they were 361±1 kJ/mol and 249±61 kJ/mol for Poly(AGE -co- AMA) and 136±24 kJ/mol and 278±18 kJ/mol for Poly(AGE -co- MMA) by FWO method. The most likely mechanisms of the main degradation stages were determined as F 3 model for Poly(AGE -co- AMA) and Poly(AGE -co- MMA). Thus, it is concluded that the thermal degradations of Poly(AGE -co- AMA) and Poly(AGE -co- MMA) copolymers exhibit similar behavior. Keywords: Thermal degradation, allyl glycidyl ether, allyl methacrylate, methyl methacrylate

Kinetic analysis of thermal decomposition of date palm residues using Coats–Redfern method

ABSTRACTThermal degradation of different date palm residues (three fibrous materials and an agro-industrial by-product) under inert and oxidative atmospheres was investigated in order to identify the degradation mechanisms and kinetics of the main thermal decomposition stages using Coats–Redfern method. The corresponding kinetic parameters of the main degradation stages were also determined. The obtained results have shown that diffusion and reaction order models are the best mechanisms describing effectively thermal degradation of the different palm date residues under both atmospheres. The obtained kinetics parameters may help predicting the pyrolysis and combustion behavior of date palm residues as well as designing the suitable reactor.