Thermal Degradation Analysis Research Articles

A Viability Study of Thermal Pre-Treatment for Recycling of Pharmaceutical Blisters

Pharmaceutical packaging is one of the most used packaging types which contains aluminum and plastics. Due to increasing amounts of waste and rising environmental concerns, recycling approaches are being investigated. Since blisters usually contain a balanced amount of plastics and metals, most of the approaches focus on recycling only one material. Therefore, more sustainable recycling approaches which recover both plastic and aluminum fractions are needed. This study investigates the thermal behavior and degradation mechanisms of plastic-rich and aluminum-rich pharmaceutical blisters using various analytical techniques. Structural characterization revealed that plastic-rich blisters have a thicker profile with plastic and aluminum layers, while aluminum-rich blisters consist of plastic layers between aluminum sheets. Thermal degradation analysis showed two main stages for both types: plastic-rich blisters (polyvinyl chloride) exhibited significant weight loss and long-chain hydrocarbon formation between 210 and 285 °C, and aluminum-rich blisters (polyamide/nylon) degraded from 240 to 270 °C. Differential Scanning Calorimetry and Fourier Transform Infrared Spectroscopy analyses confirmed the endothermic behavior of such a transformation. The gas emissions analysis indicated an increased formation of gasses from the thermal treatment of plastic-rich blisters, with the presence of oxygen leading to the formation of carbon dioxide, water, and carbon monoxide. Thermal treatment with 5%O2 in the carrier gas benefited plastic-rich blister treatment, reducing organic waste by up to 80% and minimizing burning risk, leveraging pyrolytic carbon for protection. This method is unsuitable for aluminum-rich blisters, requiring reduced oxygen or temperature to prevent pyrolytic carbon combustion and aluminum oxidation.

Thermal degradation analysis and optimization of controlled heat treatment for stacked high temperature superconducting tapes

Thermal degradation analysis and optimization of controlled heat treatment for stacked high temperature superconducting tapes

Kinetic analysis of PA4 thermal degradation: Thermal stability with respect to crystallinity

Polyamide 4 (PA4) has garnered considerable attention due to its fully bio-based origin and biodegradability as a high-performance polyamide. Nevertheless, thermal degradation during the melting process impedes thermal processing, thereby constraining its potential for engineering plastics applications. To clarify the thermal degradation reactions of PA4 amidst intricate physical and chemical transformations, establishing a theoretical foundation for the thermal stability modification, we conducted a comprehensive analysis of PA4 thermal degradation coupled with crystallization, considering kinetics and reaction mechanisms. Calculation of reaction activation energies and mechanism functions revealed that PA4 pyrolysis is a two-stage compound process, with distinct degradation mechanisms attributed to the crystalline and amorphous regions. Additionally, the thermal degradation mechanism of the PA4-CaCl2 composite system at varying crystallinity levels was illustrated. The incorporation of Ca strengthens intermolecular forces in the samples, leading to an increased overall stability. Simultaneously, a notable alteration in the reaction mechanism was observed in the crystalline zone lacking the Ca phase.

Thermal stability of binary and ternary biodegradable polymer blends assessed by isoconversional kinetic analysis

Here we report on kinetic analysis of thermal degradation of polymer blends based on incremental isoconversional method coupled with mathematical deconvolution of thermogravimetric curves based on Fraser–Suzuki peak function. The measured kinetic envelope was decomposed into contributions approximately corresponding to degradation of each constituent of a polymer blend. Kinetic parameters from isoconversional analysis were further used for estimating the effect of blending on thermal stability of the constituents. Compared to routinely used parameters such as degradation onset temperature or DTG-peak temperature, the deconvolution analysis allows to determine stability of all components in a mixture regardless of their relative content. Here we also show that deconvolution analysis can be carried out directly on integral α(T) curves, thus bypassing the work with differential data dα/dt. Isoconversional analysis of deconvoluted α(T) curves allows to calculate various parameters for assessing the potentially accelerating or inhibiting effect on thermal degradation, for example, by means of decomposition half-time t0.5. The results can be made more robust by utilizing relative criteria for stability such as t0.5(blend)/t0.5(neat polymer). Using this approach, detrimental effect of PHBV and PBAT on thermal stability of PLA above 300 °C was confirmed. On the other hand, stability of PHBV in both binary and ternary mixtures was improved compared to neat polymer.

Polylactic acid/epoxidized linseed oil/polypropylene grafted maleic anhydride: A promising combination of toughness and rigidity

AbstractIncreasing toughness of brittle polymer without losing modulus of elasticity and tensile strength is highly important for enlarging the range of applications. In this study, polylactic acid (PLA) modified with epoxidized linseed oil (ELO) and polypropylene‐grafted maleic anhydride (PPgMA) with a good balance of toughness and rigidity was successfully prepared by melt mixing procedure. The addition of PPgMA/ELO with appropriate proportions (3:1, 5:1, and 5:5 wt%) resulted in PLA modified samples with significant ductility improvement (around 2200% of elongation at break and 1800% of tensile toughness compared to the neat PLA) with low decrease in Young modulus and tensile strength. This feature was attributed to improved interfacial interactions and the formation of crosslinked structures at the interface that also increased viscosity of the melting system and cold crystallization temperature of PLA. The scanning electron microscopy revealed the presence of small domains of modified systems. The effectiveness of reactive compatibilization among the components was also suggested by Fourier transform infrared (FTIR) spectroscopy and thermal degradation analysis. The combination of toughness, modulus of elasticity and good thermal properties make this low‐cost and scalable eco‐friendly material a promising candidate for use as biodegradable plastic in several fields including medical applications and packaging.

Degradation kinetics of PLA compounds with castor oil

AbstractPoly (lactic acid) (PLA) compounds with castor oil (CO) and epoxidized castor oil (ECO) were produced via formic acid, with levels of 5% CO, 3 and 5% ECO. The contribution of this study lies in the detailed analysis of thermal degradation and degradation kinetics of PLA/CO and PLA/ECO. Chemical changes were evidenced by Fourier transform infrared (FTIR), thermal stability, and degradation kinetics were investigated by thermogravimetric analysis (TGA), using Friedman (FR), Ozawa–Flynn–Wall (OFW), Kissinger–Akahira–Sunose (KAS) and Vyazovkin (VZ) models. Results showed changes in FTIR spectra for PLA/CO and PLA/ECO. For PLA/5%CO and PLA/3%ECO, lower energy bonds formation were observed, resulting in modifications in the involved molecules and presence of CH type bonds in PLA/5%ECO. TGA analysis showed that PLA presented greater thermal stability compared with PLA/CO and PLA/ECO, with T5% = 306°C. The compounds 5% CO, 3 and 5% ECO exhibited lower degradation temperatures (298, 300, and 296°C), compared with PLA, as well as slower decomposition rates. Kinetic modeling using KAS and OFW models proved to be incapable of describing the degradation kinetics of PLA and its compounds. However, FR and VZ were considered adequate, with discrepancies varying between 7% to −4% and 9% to −3%, which showed higher (215, 185, 210, 189 KJ/mol) at α = 0.3 for PLA.

An evaluation of the cannabinoid content of the liquid and thermal degradation analysis of cannabis-labeled vape liquids.

Cannabidiol (CBD) vape pen usage has been on the rise given the changing political and scientific climate as well as the promotion of these delivery systems as a more accessible and lower-risk option for consumers. Despite being marketed as a safer way to use cannabis, CBD vape liquids are sold without restrictions or meticulous quality control procedures such as toxicological and clinical assessment, standards for product preservation, or investigative degradation analyses. Nine CBD-labeled vape liquid samples purchased and manufactured in the United States were evaluated and assessed for cannabinoid content. Quantification and validation of cannabinoids and matrix components was accomplished using gas and liquid chromatography with mass spectrometry analysis (GC-MS and LC-MS/MS) following liquid-liquid extraction with methanol. Samples degraded by temperature (analyzed by GC-MS) showed a greater disparity from the labeled CBD content compared with samples analyzed as purchased (by LC-MS/MS). Thermal degradation of the vape liquids showed increased levels of tetrahydrocannabinol (THC). Also, extended time and temperature degradation were evaluated in vape liquids by storing them for 15 months and then varying temperature conditions before analysis, which indicated CBD transformed into other cannabinoids leading to different cannabinoid content within the vape samples. Evaluation conducted on these vape liquids indicated the route of exposure, storage conditions, and length of storage could expose consumers to unintended cannabinoids and showed a concerning level of disagreement between the products' labeled cannabinoid content and the results generated by these analyses.

Development of lactic acid based chain extender and soybean oil-derived polyurethanes for ecofriendly sustained drug delivery systems

In the present study, a range of sustainable, biocompatible and biodegradable polyurethanes (PU-1 to PU-4) were synthesized using different combinations of biobased polyol (obtained through the epoxidation of soybean oil, followed by ring opening with ethanol) and polyethylene glycol (PEG) and isophorone diisocyanate. The sustainable chain extender used in this study was synthesized by the esterification of lactic acid with ethylene glycol (EG). The synthesized PU samples were characterized through scanning electron microscopy (SEM), Fourier transformed infrared (FTIR) and nuclear magnetic resonance (1H NMR and 13C NMR) spectroscopy. Wetting ability and thermal degradation analysis (TGA) of the samples were also studied. Subsequently, these PUs were examined as potential drug delivery systems using Gabapentin as a model drug, which was loaded in the polymer matrix using the solvent evaporation method. The drug release studies were carried out in 0.06 N HCl as a release medium according to the method outlined in the United States Pharmacopeia. The maximum drug release was observed for sample PU-P1, which was found to be 53.0 % after 6 h. Moreover, a comparison of different PU samples revealed a trend wherein the values of drug release were decreased with an increase in the PEG content.

Synthesis, self-aggregation, thermal stability and cytotoxicity trends of alkyloxypropoxycyclohexane based pyridinium ionic liquids

New ether-functionalized pyridinium ionic liquids (ILs) has been synthesized by simple methodology and described by different spectroscopic techniques. Presence of two positional isomers has been confirmed with the help of NMR spectroscopy. The critical micelle concentration and other surface parameters of these ILs were deduced by conductivity, surface tension and fluorescence method. A collection of useful physical parameters i.e. critical micelle concentration (cmc), surface tension accomplished at cmc (γcmc), effectiveness of diminution in surface tension (Πcmc), maximum surface excess concentration (Ʈmax) and minimum surface area per molecule (Amin) at the air–water interface were also estimated. The average size of aggregates formed by investigated pyridinium ILs have been well examined by dynamic light scattering (DLS) experiments. The thermal degradation analysis of the present ILs has also been suggested that these ILs possessed thermal stability ranges from 200 °C to 240 °C. The investigated ILs have also been tested by MTT assay (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) on the C6 glioma cell line and found to revealed very low cytotoxicity in the concentration range required for biomedical applications. Such a low cytotoxicity of present ILs opens several new applications in the many biological purposes like drug and gene delivery agents. The physical study of investigated ILs indicate that the presence of ether functionality and varying hydrophobic chain length significantly altered the physicochemical properties of these pyridinium ILs than related to earlier synthesized N-(cyclohexanoxycarbonylmethyl) and 3-Cyclohexyloxy-2-Hydroxypropyl Pyridinium and Imidazolium surface active ILs.

Comprehensive characterization and kinetic analysis of coconut shell thermal degradation: Energy potential evaluated via the Coats-Redfern method

Coconut shell represents a promising biomass for energy production, given their wide availability. In this study, the thermo-kinetics of coconut shells were examined through thermogravimetric analysis from 30 °C to 1000 °C at 5 °C/min under N2. Advanced analytical tools assessed the elemental, microstructural, and morphological attributes of the samples. The thermal degradation unveiled three phases: dehydration, devolatilization, and combustion. Notably, the Coats-Redfern method detailed the devolatilization stage, pinpointing the coconut shell's thermal and kinetic attributes. The Zhuravlev diffusion equation (DM6) emerged as the most suitable model, with an activation energy (Ea) and pre-exponential factor of 68.9 kJ mol−1 and 0.05 min−1, respectively. Thermodynamic values such as enthalpy (ΔH), Gibbs free energy (ΔG), and entropy (ΔS) for devolatilization were 65.2, 193.1, and −0.28117, respectively. Collectively, the findings underscore the significant bioenergy potential of coconut shells, positioning them as a sustainable alternative to traditional energy. Such insights play a crucial role in improving pyrolysis reactor designs and comprehending the mechanisms of coconut shell pyrolysis, offering potential solutions for energy deficits and environmental concerns.

Sustainable Innovation: Fabrication and Characterization of Mycelium-Based Green Composites for Modern Interior Materials Using Agro-Industrial Wastes and Different Species of Fungi.

Mycelium-based bio-composites (MBCs) represent a sustainable and innovative material with high potential for contemporary applications, particularly in the field of modern interior design. This research investigates the fabrication of MBCs for modern interior materials using agro-industrial wastes (bamboo sawdust and corn pericarp) and different fungal species. The study focuses on determining physical properties, including moisture content, shrinkage, density, water absorption, volumetric swelling, thermal degradation, and mechanical properties (bending, compression, impact, and tensile strength). The results indicate variations in moisture content and shrinkage based on fungal species and substrate types, with bamboo sawdust exhibiting lower shrinkage. The obtained density values range from 212.31 to 282.09 kg/m3, comparable to traditional materials, suggesting MBCs potential in diverse fields, especially as modern interior elements. Water absorption and volumetric swelling demonstrate the influence of substrate and fungal species, although they do not significantly impact the characteristics of interior decoration materials. Thermal degradation analysis aligns with established patterns, showcasing the suitability of MBCs for various applications. Scanning electron microscope observations reveal the morphological features of MBCs, emphasizing the role of fungal mycelia in binding substrate particles. Mechanical properties exhibit variations in bending, compression, impact, and tensile strength, with MBCs demonstrating compatibility with traditional materials used in interior elements. Those produced from L. sajor-caju and G. fornicatum show especially promising characteristics in this context. Particularly noteworthy are their superior compression and impact strength, surpassing values observed in certain synthetic foams multiple times. Moreover, this study reveals the biodegradability of MBCs, reaching standards for environmentally friendly materials. A comprehensive comparison with traditional materials further supports the potential of MBCs in sustainable material. Challenges in standardization, production scalability, and market adoption are identified, emphasizing the need for ongoing research, material engineering advancements, and biotechnological innovations. These efforts aim to enhance MBC properties, promoting sustainability in modern interior applications, while also facilitating their expansion into mass production within the innovative construction materials market.

Physicochemical synergistic effect of microwave-assisted Co-pyrolysis of biomass and waste plastics by thermal degradation, thermodynamics, numerical simulation, kinetics, and products analysis

Understanding the physicochemical synergistic effect of microwave-assisted co-pyrolysis (MACP) of biomass and waste plastics is crucial for efficient conversion and improving the quality of bio-oil. Thermal degradation, thermodynamics, and numerical simulation of co-pyrolysis of the corncob (CC) and polystyrene (PS) were conducted. Results showed that the co-pyrolysis of CC and PS had a positive physical synergistic and compatible effect in reducing energy consumption and accelerating reaction rate. The reaction kinetics analysis and pyrolysis products analysis found that the co-pyrolysis of CC and PS had a positive chemical synergistic effect. The co-pyrolysis both effectively reduced the pyrolysis activation energy and improved the yield and quality of bio-oil. Significantly, the sample of CC/PS (1:2) had the highest yield of bio-oil (52.3 wt%) and the highest relative content of aromatics (95.0 area%) in co-pyrolysis, while 450 °C was the most ideal pyrolysis temperature. This work indicated that the MACP of CC and PS showed a positive physicochemical synergistic effect, and provided theories and approaches for the production of bio-oil from the biomass and waste plastics by MACP.

Modeling and Analysis of Coupled Thermal and Mechanical Capacity Degradation in Silicon-Based Lithium-Ion Batteries

Large-format cells are gaining popularity for battery electric vehicles (BEVs) to maximize volumetric and gravimetric energy densities but are associated with challenges in ensuring adequate thermal management. Spatial current density and temperature variations negatively affect overall cell utilization and lifetime.In addition, the mechanical stresses generated within the silicon-based battery electrodes also cause aging and resultant capacity loss. The coupled effects of the thermal and mechanical factors could thus particularly exacerbate cell capacity degradation. Rigorous mechano-thermo-electrochemical models for battery degradation can be a powerful complementary tool to understand these phenomena better. Simulating performance scenarios can significantly improve cell design and experimentation while reducing time and cost commitments. Model-based design approaches thus have the potential to yield substantial economic benefits.This work shall serve as an extension to the previously developed thermal degradation model for non-uniform aging in lithium-ion batteries by coupling with mechanical models predicting the effects of volume change within the batteries over cycling. The observed capacity fade trend for a given battery is ultimately the result of an interplay between multiple degradation mechanisms, which depend on a range of design and operating parameters. The errors between the model predictions and experimental data can provide information on the suitability of a given model and the relative prevalence of a given degradation mechanism, with functional and practical benefits, as there exists significant variation in the parameters, mechanisms, and predictive capability of models in the literature. In addition, a rigorous model of volume changes increases the accuracy of predictions of dynamic stress-strain profiles, which in turn helps improve predictions of associated mechanical degradation phenomena. As a first step towards including mechanical effects, the current model builds on the previously reported studies for modeling volume change in porous electrodes due to intercalation (deintercalation) during lithiation (delithiation). This volume change leads to dimensional and porosity changes in the porous electrodes. Furthermore, these mechanical models will help predict generated stresses and strain profiles within the battery and will be related to models of resultant degradation, especially in the case of silicon/graphite electrodes characterized by substantial volume changes.

Bio-Based PLA/PBS/PBAT Ternary Blends with Added Nanohydroxyapatite: A Thermal, Physical, and Mechanical Study.

The physical and mechanical properties of novel bio-based polymer blends of polylactic acid (PLA), poly(butylene succinate) (PBS), and poly (butylene adipate-co-terephthalate) (PBAT) with various added amounts of nanohydroxyapatite (nHA) were investigated in this study. The formulations of PLA/PBS/PBAT/nHA blends were divided into two series, A and B, containing 70 or 80 wt% PLA, respectively. Samples of four specimens per series were prepared using a twin-screw extruder, and different amounts of nHA were added to meet the regeneration needs of bone graft materials. FTIR and XRD analyses were employed to identify the presence of each polymer and nHA in the various blends. The crystallization behavior of these blends was examined using DSC. Tensile and impact strength tests were performed on all samples to screen feasible formulations of polymer blends for bone graft material applications. Surface morphology analyses were conducted using SEM, and the dispersion of nHA particles in the blends was further tested using TEM. The added nHA also served as a nucleating agent aimed at improving the crystallinity and mechanical properties of the blends. Through the above analyses, the physical and mechanical properties of the polymer blends are reported and the most promising bone graft material formulations are suggested. All blends were tested for thermal degradation analysis using TGA and thermal stability was confirmed. The water absorption experiments carried out in this study showed that the addition of nHA could improve the hydrophilicity of the blends.

The quantification of gaseous chemical compounds in the smoke from rigid polyurethane and rigid polyisocyanurate foam by a standardless evolved gas analysis method

This paper describes the results of quantifying gaseous chemical compounds in smoke, which were obtained from thermal degradation analyses of rigid polyurethane (PU) and rigid polyisocyanurate (PIR) foam. The analytical method used was evolved gas analysis, which consisted of a combination of two different analytical methods: thermogravimetric/differential thermal analysis-Fourier-transform infrared spectroscopy (TG/DTA-FTIR) and pyrolysis gas chromatography-mass spectrometry (Py-GC/MS). A lack of specific internal standards for measuring the released gases in thermal degradation analyses was solved by introducing a mathematical formula to indirectly determine the absolute mass values for the chemical compounds of interest. The combined method allowed for the quantification of absolute masses of the released gaseous chemical compounds in the smoke without the use of internal standards. This method has the potential to be used in quantifying gaseous chemical compounds in other foam materials as well.

An experimental investigation on kinetic analysis of thermal degradation of shape stable composite phase change materials and adaptive neuro fuzzy inference system modeling for predicting mass loss

An experimental investigation on kinetic analysis of thermal degradation of shape stable composite phase change materials and adaptive neuro fuzzy inference system modeling for predicting mass loss

Molecularly Imprinted Polymer-Based Nanoporous Carbon Nanocomposite for Effective Adsorption of Hg(II) Ions from Aqueous Suspensions

Due to the release of hazardous heavy metals from various industries, water pollution has become one of the biggest challenges for environmental scientists today. Mercury Hg(II) is regarded as one of the most toxic heavy metals due to its ability to cause cancer and other health issues. In this study, a tailor-made modern eco-friendly molecularly imprinted polymer (MIP)/nanoporous carbon (NC) nanocomposite was synthesized and examined for the uptake of Hg(II) using an aqueous solution. The fabrication of the MIP/NC nanocomposite occurred via bulk polymerization involving the complexation of the template, followed by polymerization and, finally, template removal. Thus, the formed nanocomposite underwent characterizations that included morphological, thermal degradation, functional, and surface area analyses. The MIP/NC nanocomposite, with a high specific surface area of 884.9 m2/g, was evaluated for its efficacy towards the adsorptive elimination of Hg(II) against the pH solution changes, the dosage of adsorbent, initial concentration, and interaction time. The analysis showed that a maximum Hg(II) adsorption effectiveness of 116 mg/g was attained at pH 4, while the Freundlich model fitted the equilibrium sorption result and was aligned with pseudo-second-order kinetics. Likewise, thermodynamic parameters like enthalpy, entropy, and Gibbs free energy indicated that the adsorption was consistent with spontaneous, favorable, and endothermic reactions. Furthermore, the adsorption efficiency of MIP/NC was also evaluated against a real sample of condensate from the oil and gas industry, showing an 87.4% recovery of Hg(II). Finally, the synthesized MIP/NC showed promise as a selective adsorbent of Hg(II) in polluted environments, suggesting that a variety of combined absorbents of different precursors is recommended to evaluate heavy metal and pharmaceutical removals.

Pentaerythritol and Glycerol Esters Derived from Gum Rosin as Bio-Based Additives for the Improvement of Processability and Thermal Stability of Polylactic Acid

Gum rosin esters are some of the most common gum rosin derivatives used in different applications, such as coatings, paper, varnishes, chewing gum, and food industries. In this study, gum rosin esters are used as additives for polylactic acid (PLA) to improve its processability and thermal stability. Blends of an amorphous PLA with two different gum rosin esters, pentaerythritol ester and glycerol ester, were prepared by melt extrusion process in concentrations from 1, 3, and 5 phr. Besides the comparison of thermal degradation, microstructure assessment, and melt flow index (MFI) analysis, the processability performance during testing samples production by injection molding process was evaluated. Experimental results showed that MFI values of PLA-gum rosin ester blends increased by 100%, 147%, and 164%, along with increasing content of gum rosin esters addition, in both cases. Also, both derivatives slightly improved PLA thermal stability (around 3ºC higher). Injection molding temperature decreased by at least 20 °C for PLA-gum rosin ester blends compared with neat PLA. Furthermore, the maximum tensile strength of PLA-gum rosin esters was negligibly affected in formulations with low content of gum rosin esters, and the FESEM images revealed a good dispersion and compatibility of gum rosin ester particles into PLA matrix in both concentrations.

Activation Energy Analysis of Thermal Degradation of Bamboo Fiber as a Reinforcing Material in Bio-Composites

Activation Energy Analysis of Thermal Degradation of Bamboo Fiber as a Reinforcing Material in Bio-Composites

Development of polypyrrole-coated cotton thermoelectric fabrics

Polypyrrole (PPy) is most widely used conductive polymer for conductive textile applications owing to its excellent electrical conductivity, good electromagnetic shielding, good anti-bacterial properties, etc. However, it has not been explored much as thermoelectric material. PPy can be coated on cotton fabric in aqueous media from its monomer to prepare electro-conductive fabrics, which will be a flexible organic thermoelectric material. In this study, PPy-coated cotton fabrics are prepared by in situ chemical polymerisations of pyrrole in presence of ferric chloride. The polymerisation process is optimised by employing Box–Behnken response surface design and method of steepest ascent to achieve minimum electrical resistivity. The lowest resistivity of PPy-coated cotton fabric is achieved to be 1.23 Ω/cm after the optimisation. The PPy-coated cotton fabric with copper thermocouple shows Seebeck coefficient as high as 11.95 µV/K, power factor 0.139 µW m−1 K−2, and thermoelectric figure of merit 1.22 × 10−4 at an absolute temperature of 300K. The thermoelectric performance of this coated fabric is found to be comparable to other costly conductive polymers and inorganic semiconductors. The surface morphology of PPy-coated cotton fabric is observed by field-emission scanning electron microscopy. Chemical interaction between cotton and PPy is investigated by FTIR spectroscopy. Analysis of semi-crystalline structure is done by X-ray diffraction and thermo-gravimetric analyser is used for analysis of thermal degradation.