Theoretical and analyzed data related to thermal degradation kinetics of poly ( L -lactic acid)/chitosan- grafted -oligo L -lactic acid (PLA/CH- g -OLLA) bionanocomposite films

Pal, Akhilesh Kumar; Katiyar, Vimal

doi:10.1016/j.dib.2016.11.100

Cited by 14 publications

(4 citation statements)

References 13 publications

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“…It was noted that for each sample, peak temperatures shifted with increasing heating rates. Using the peak temperature for different heating rates, the activation energy was calculated using both Kissinger and Flynn-Wall-Ozawa models [30,31]. The thermo-kinetic investigation was carried out to determine the amount of energy required for the carbon-oxygen reaction to take place.…”

Section: Resultsmentioning

confidence: 99%

Smart Self-Sensing Piezoresistive Composite Materials for Structural Health Monitoring

et al. 2022

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The use of fiber-reinforced composite materials has widely spread in various sectors, including aerospace, defense, and civil industry. The assessment of these heterogeneous material systems is important for safer and risk-free applications and has contributed to the need for self-sensing composites. This work is focused on the development of piezoresistive composites, the prediction of their performance and structural health monitoring (SHM). Additionally, this work unpacks the complexity of carbon nanotubes (CNTs) micro-fabrication and the development of piezoresistive and electromagnetic (EM) waves detection electrodes. Scanning electron microscopy (SEM) was used to characterize the CNTs structure and morphologies. The manufactured CNTs were incorporated in epoxy systems to fabricate glass fiber reinforced polymer (GFRP)-CNTs smart composites with piezoresistive properties. The detection of micro-damage onset and its progression was carried out in mode I, to evaluate the sensitivity of the smart composites to damage development. The change in electrical conductivity of the nanotubes-reinforced composite systems due to localized mechanical strains enabled crack propagation detection. The relationship between crack propagation, fracture toughness, and electrical resistivity of the smart composite was analyzed.

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Section: Resultsmentioning

confidence: 99%

Smart Self-Sensing Piezoresistive Composite Materials for Structural Health Monitoring

et al. 2022

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“…In this study, for the the thermal degradability of PBT–EVOH composite films we followed the Ozawa method to determine the corresponding thermal degradation activation energy of the polymer. The Ozawa equation is listed here as [ 39 , 40 ]: − logA 1 − 0.4567 ( Ea/RT 1 ) = − logA 2 − 0.4567 ( Ea/RT 2 ) where Ai is the heating rate, Ea is the activation energy, and T is the temperature in Kelvins.…”

Section: Methodsmentioning

confidence: 99%

Thermal Degradation Kinetics Analysis of Polymer Composite Electrolyte Membranes of PEVOH and PBT Nano Fiber

Lin

2022

Polymers

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The thermal degradation kinetics of high-performance polymer composite electrolyte membranes were investigated by thermal gravimetric analysis in this study. The novel porous polymer composite membranes were fabricated by crosslinking poly (ethylene-co-vinyl alcohol) (EVOH) with polybutylene terephthalate (PBT) nano fiber. The PBT nano-scale fiber non-woven cloth was first prepared by the electrospinning method to form a labyrinth-like structure, and the crosslinking was carried out by filtering it through a solution of EVOH and crosslinking agent triallylamine using the Porcelain Buchner funnel vacuum filtration method. The PBT–EVOH composite membranes with various crosslinking agent ratios and ethylene carbonate/dimethyl carbonate (EC/DMC) immersion times were investigated for their thermal stability and ionic conductivity. The results showed that the higher crosslinking agent content would lower the crystallinity and enhance thermal stability. The thermal degradation activation energy was dramatically increased from 125 kJ/mol to 340 kJ/mol for the 1.5% crosslinking agent content sample at 80% conversion. The triallylamine crosslinking agent was indeed effective in improving thermal degradation resistivity. The best ionic conductivity of the polymer composite membranes was exhibited at 5.04 × 10−3 S cm−1 using the optimal weight ratio of EVOH/PBT composite controlled at 1/2. On the other hand, the EC/DMC immersion time was more effective in controlling the Rb value, thus the ionic conductivity of the membranes. A higher immersion time, such as 48 h, not only gave higher conductivity data but also provided more stable results. The triallylamine crosslinking agent improved the membrane ionic conductivity by about 22%.

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“…The FWO integral isoconversional method is a fairly simple and widely used method to determine the value of the activation energy (E a ) of a decomposition process, using the data collected from the thermogravimetric curve (TG). The FWO method is based on the assumption that the conversion function does not fluctuate with the modification of the heating rate for all values of the conversion degree and it acts according to the Arrheniustype temperature dependence without changing the form of the kinetic equation [35,36].…”

Section: Introductionmentioning

confidence: 99%

Thermal Stability and Kinetics of Degradation of Moxonidine as Pure Ingredient vs. Pharmaceutical Formulation

Baul,

Ledeţi,

Cîrcioban

et al. 2023

Processes

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The stability of active pharmaceutical ingredients (APIs) and the corresponding pharmaceutical formulations are nowadays of great importance in pharmaceutical research and technology. The quality of an API or of finished pharmaceutical products (FPPs) is time dependent under the influence of several parameters, such as light and air exposure, temperature, and humidity. Additionally, the stability profile of an API is influenced by the formulation composition, due to the presence of excipients or by the characteristic of the packaging materials. In this sense, the main objective of this study was to analyze the degradation kinetics of the antihypertensive drug moxonidine as a pure ingredient (MOX) and in two different solid mixtures, one corresponding to a pharmaceutical formulation (MOXTAB) and the other to an enriched pharmaceutical formulation in MOX (MOXMIX). As investigation techniques, FTIR (Fourier transform infrared) spectroscopy and TG/DTG/HF analysis were employed, while the thermoanalytical data were processed according to the ASTM E698 kinetic method and the isoconversional methods of Flynn–Wall–Ozawa (FWO) and Friedman (FR). The kinetic methods revealed that the excipients have a stabilizing effect on MOX (in terms of Ea values), but the decomposition mechanism of the samples is complex, according to the results suggested by the analysis of Ea vs. α values.

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Theoretical and analyzed data related to thermal degradation kinetics of poly ( L -lactic acid)/chitosan- grafted -oligo L -lactic acid (PLA/CH- g -OLLA) bionanocomposite films

Cited by 14 publications

References 13 publications

Smart Self-Sensing Piezoresistive Composite Materials for Structural Health Monitoring

Smart Self-Sensing Piezoresistive Composite Materials for Structural Health Monitoring

Thermal Degradation Kinetics Analysis of Polymer Composite Electrolyte Membranes of PEVOH and PBT Nano Fiber

Thermal Stability and Kinetics of Degradation of Moxonidine as Pure Ingredient vs. Pharmaceutical Formulation

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