Mechanisms involved in thermal degradation of lignocellulosic fibers: a survey based on chemical composition

Ornaghi, Heitor Luiz; Ornaghi, Felipe Gustavo; Neves, Roberta Motta; Monticeli, Francisco Maciel; Bianchi, Otávio

doi:10.1007/s10570-020-03132-7

Cited by 41 publications

(35 citation statements)

References 27 publications

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“…Usually, cellulose shows a one-step degradation from 300 to 400°C (Fig. 2b) due to the depolymerization of cellulose chains (Ornaghi et al, 2020). For MCC, a shoulder around 310°C was observed associated with the dehydration of cellulose to dehydrocellulose as reported by Das et al, 2010).…”

Section: Amount Of Aptes Grafted Onto MCC Surfacementioning

confidence: 57%

In-Depth Study of the Microcrystalline Cellulose Amino-Functionalization Efficiency

Duchemin

et al. 2021

Preprint

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Microcrystalline cellulose (MCC) has unique properties and its use as reinforcement for polymer composites has been increasing. However, the intrinsic incompatibility with most polymers requires surface modification to improve chemical compatibility prior to its incorporation into a polymer. In this paper, an in-depth study of silanization of MCC using 3-aminopropyltriethoxysilane (APTES), at different concentration, was done. The grafting amount of APTES onto MCC was determined by different methods: from residual mass and from nitrogen content. Solid-state 13C and 29Si nuclear magnetic resonance (NMR), field emission scanning electron microscopy with energy dispersive X-ray (SEM-EDX), spectroscopy plasma optical emission spectrometry (ICP), and a deep study of structural properties by X-ray diffraction were carried out. A better correlation for grafting amount of APTES onto MCC was observed for nitrogen content method than residual mass according the Pearson’s correlation. 13C NMR revealed all the carbon structures from cellulose and from APTES molecules and 29Si NMR revealed D, T and Q Si structures. The silane treatment did not alter the shape of MCC and all treated samples showed Si characteristic peak at ~ 1.75 kEv. From ICP was observed higher Si content before MCC addition than after, evidencing, once again, APTES grafting. The exposure to APTES in acidic medium caused several effects on the MCC, splitting larger Iβ crystallites in half and along the more reactive hydrophilic sides. The diameter of the smaller IVI crystallites was largely reduced by the treatment, especially when the silane concentration was 1:5 (m/v), above which the diameter increases again.

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Section: Amount Of Aptes Grafted Onto MCC Surfacementioning

confidence: 57%

In-Depth Study of the Microcrystalline Cellulose Amino-Functionalization Efficiency

Duchemin

et al. 2021

Preprint

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“…Three visible main loss stages are visualized: i) at around 100 °C a mass loss of 5% can be mainly attributed to the evaporation of intrinsic moisture, ii) at around 300 °C a more abrupt mass loss attributed mainly to hemicellulose that extends up to 350 °C and, iii) from 350 °C to 400 °C the degradation of cellulose (the main component) in a narrower range, representing the main degradation stage. Lignin degrades overall extension range [7,22,23]. All the curves above were used to calculate the kinetic parameters using the Vyazovkin kinetic model in the temperature range from 100 to 435 °C (main degradation stage).…”

Section: Resultsmentioning

confidence: 99%

“…This potential of application can be attributed to the wide variety of chemical components (cellulose, hemicellulose, lignin, waxes, low molecular weight components, oil, etc. ) presented in the lignocellulosic fibers [7,8]. Also, the same fiber can have different properties depending on the plant age, climate, soil among others [9].…”

Section: Introductionmentioning

confidence: 99%

“…According to the authors, all components affected the activation energy. Ornaghi Jr. et al [7] studied the mechanisms involved in the thermal degradation of lignocellulosic fibers based on the chemical composition. The main results indicate that the activation energy of the fibers followed similar values to the cellulose component and that the thermogravimetric curves followed a similar pattern, independently of the chemical composition.…”

Section: Introductionmentioning

confidence: 99%

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Application of the Artificial Neural Network (ANN) Approach for Prediction of the Kinetic Parameters of Lignocellulosic Fibers

Ornaghi¹,

Neves²,

Monticeli³

2021

Preprint

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Lignocellulosic fibers are widely applied as composite reinforcement due to their properties. The thermal degradation behavior determines the maximum temperature in which the fiber can be applied without significant mass loss. It is possible to determine these temperatures using Thermogravimetric Analysis (TG). In particular, when curves are obtained at different heating rates, kinetic parameters can be determined and more detailed characteristics of the material are obtained. However, every curve obtained at a distinct heating rate demands material, cost, and time. Methods to predict thermogravimetric curves can be very useful in the materials science field and in this sense mathematical approaches are powerful tools if well employed. For this reason, in the present study, curaua TG curves were obtained at three different heating rates (5, 10, 20, and 40 °C.min-1) and Vyazovkin kinetic parameters were obtained. After, the experimental curves were fitted using an artificial neural network (ANN) approach followed by a Surface Response Methodology (SRM). Curves at any heating rate between the minimum and maximum experimental heating rates were obtained with high reliability. Finally, Vyazovkin kinetic parameters were tested again with the new curves showing similar kinetic parameters from the experimental ones. In conclusion, due to the capability to learn from the own data, ANN combined with SRM seems to be an excellent alternative to predict TG curves that do not test experimentally, opening the range of applications.

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“…Hemicellulose primarily contributes to the thermal stability, cellulose to the Arrhenius parameters, and lignin to the final stage of the weight loss curve. [ 74 ]…”

Section: Fiber‐reinforced Plamentioning

confidence: 99%

Flame retardancy and thermal stability of agricultural residue fiber‐reinforced polylactic acid: A Review

et al. 2020

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Biocomposites containing natural fibers and biopolymers are an ideal choice for developing substantially biodegradable materials for different applications. Polylactic acid is a biopolymer produced from renewable resources and has drawn numerous interest in packaging, electrical, and automotive application in recent years. However, its potential application in both electrical and automotive industries is limited by its flame retardancy and thermal properties. One way to offset this challenge has been to incorporate natural or synthetic flame retardants in polylactic acid (PLA). The aim of this article is to review the trends in research and development of composites based on agricultural fibers and PLA biopolymers over the past decade. This article highlights recent advances in the fields of flame retardancy and thermal stability of agricultural fiber‐reinforced PLA. Typical fiber‐reinforced PLA processing techniques are mentioned. Over 75% of the studies reported that incorporation of agricultural fibers resulted in enhanced flame retardancy and thermal stability of fiber‐reinforced PLA. These properties are further enhanced with surface modifications on the agricultural fibers prior to use as reinforcement in fiber‐reinforced PLA. From this review it is clear that flame retardancy and thermal stability depends on the type and pretreatment method of the agricultural fibers used in developing fiber‐reinforced PLA. Further research and development is encouraged on the enhancement of the flame retardancy properties of agricultural fiber‐reinforced PLA, especially using agricultural fibers themselves as flame retardants as opposed to synthetic flame retardants that are typically used.

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Mechanisms involved in thermal degradation of lignocellulosic fibers: a survey based on chemical composition

Cited by 41 publications

References 27 publications

In-Depth Study of the Microcrystalline Cellulose Amino-Functionalization Efficiency

In-Depth Study of the Microcrystalline Cellulose Amino-Functionalization Efficiency

Application of the Artificial Neural Network (ANN) Approach for Prediction of the Kinetic Parameters of Lignocellulosic Fibers

Flame retardancy and thermal stability of agricultural residue fiber‐reinforced polylactic acid: A Review

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