Kinetic analysis and reaction mechanism of p-alkoxybenzyl alcohol ([4-(hydroxymethyl)phenoxymethyl]polystyrene) resin pyrolysis: Revealing new information on thermal stability

Janković, Bojan; Manić, Nebojša

doi:10.1016/j.polymdegradstab.2021.109606

Cited by 17 publications

(7 citation statements)

References 59 publications

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“…Table 7 shows the activation energy values for PP from different published papers. It can be concluded that the activation energy values of this paper are between the highest value (225 kJ mol −1 ) by FWO and the lowest value (67 kJ mol − ) by FR (Paik and Kar (2008) [ 24 ]).…”

Section: Resultsmentioning

confidence: 96%

Kinetics Study of Polypropylene Pyrolysis by Non-Isothermal Thermogravimetric Analysis

Dubdub

2023

Materials

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Polypropylene (PP) is considered as one of six polymers representative of plastic wastes. This paper attempts to obtain information on PP polymer pyrolysis kinetics with the help of thermogravimetric analysis (TGA). TGA is used to measure the weight of the sample with temperature increases at different heating rates—5, 10, 20, 30, and 40 K min−1—in inert nitrogen. The pyrolytic kinetics have been analyzed by four model-free methods—Friedman (FR), Flynn–Wall–Qzawa (FWO), Kissinger–Akahira–Sunose (KAS) and Starnik (STK)—and by two model-fitting methods—Coats–Redfern (CR) and Criado methods. The values of activation energies of PP polymer pyrolysis at different conversions are in good agreement with the average of (141, 112, 106, 108 kJ mol−1) for FR, FWO, KAS and STK, respectively. Criado methods have been implemented with the CR method to obtain the reaction mechanism model. As per Criado’s method, the most controlling reaction mechanism has been identified as the geometrical contraction models—cylinder model.

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Section: Resultsmentioning

confidence: 96%

Kinetics Study of Polypropylene Pyrolysis by Non-Isothermal Thermogravimetric Analysis

Dubdub

2023

Materials

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“…As can be seen from Figure S2, the obtained logA(α) profiles show an identical trend with α, as well as E a (α) profiles, thus confirming the multi-step (complex) nature of the investigated process. Considering the narrow α-range where the negative logA values occur, there are very small pre-exponential factors, which bring about an extremely high term, exp(−E a,α /RT α ) ≈ ×10 15 . This results in a drastic decrease in the rate constant with increasing temperatures, i.e., it has a negative temperature dependence; or in other words, the rate decreases with an increase in the temperature.…”

Section: Results Of Multiconversional Dependent Analysis-model-free K...mentioning

confidence: 99%

“…The first mass loss step (3.44%) matches the moisture evaporation from the resin surface (characterized by the small endothermic effect that occurs till 100 °C) [15]. The specified mass loss of the sample also includes the volatilization process of divinylbenzene (DVB) since the resin is cross-linked with 1% DVB ("resin softening") [15]. This process occurs in a temperature range of approximately ΔT~100-210/220 °C, without notable thermal effects (Figure 1b, stage "I").…”

Section: Thermal and Thermo-oxidative Propertiesmentioning

confidence: 95%

“…In this case, it is possible that the eventual initial endothermicity is masked by the high exothermicity of the process, initially slower, of significantly lighter resin fractions and later by an increasingly rapid process, related to heavy resin residues. Namely, the temperature ranges between 100 • C and 220 • C can be attributed to the transformation initiated by the reaction of residual double bonds in the DVB/PS-supported resin core [15]. The second mass loss step (23.06%) (Figure 1a) covers the temperature range between 220 • C and approx.…”

Section: Thermal and Thermo-oxidative Propertiesmentioning

confidence: 97%

“…Based on the TGA/DTA data, it can be seen that degradation chemistry represents a mixture of complex reactions, with different thermal effects (Figure 1b). The first mass loss step (3.44%) matches the moisture evaporation from the resin surface (characterized by the small endothermic effect that occurs till 100 • C) [15]. The specified mass loss of the sample also includes the volatilization process of divinylbenzene (DVB) since the resin is cross-linked with 1% DVB ("resin softening") [15].…”

Section: Thermal and Thermo-oxidative Propertiesmentioning

confidence: 99%

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Application of Model-Free and Model-Based Kinetic Methods in Evaluation of Reactions Complexity during Thermo-Oxidative Degradation Process: Case Study of [4-(Hydroxymethyl)phenoxymethyl] Polystyrene Resin

Janković,

Dodevski,

Veljković

et al. 2024

Fire

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This work examined the possibilities and limitations of model-free and model-based methods related to decrypting the kinetic complexity of multi-step thermo-oxidative degradation processes (as a testing system, a [4-(hydroxymethyl)phenoxymethyl] polystyrene resin was used), monitored by thermal analysis (TGA-DTG-DTA) techniques. It was found that isoconversional methods could successfully determine the correct number of process stages and presence of multiple reactions based on derived Ea(α) profiles and identify the negative dependence of the rate constant on the temperature. These methods could not overcome the problem that arose due to mass transfer limitations. The model-based method overcame more successfully the problem associated with mass transfer because its calculation machinery had capabilities for the correct solution of the total mass balance equation. However, a perfect fit with the experimental data was not achieved due to the dependence on the thermal history of the contribution (ctb.) of a given reaction step inside a fitting procedure cycle. On the other hand, through this approach, it was possible to estimate the rate-controlling steps of the process regarding the influence of the heating rate. It was found that for consecutive reaction mechanisms, the production of benzaldehyde and gases in high yields was controlled by the heating rate, where low heating rates were strongly recommended (≤10 K/min). Also, it was shown that the transport phenomenon may be also the rate-determining step (within the set of “intrinsic” kinetic parameters). It was also established that external heat transfer controls the overall rate, where the “pure” kinetic control regime had not been reached but was approached when lowering the temperature and size of the resin particles.

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The kinetic models analyses of hydrogenated natural rubber during non‐isothermal degradation process

Lang

Tang

Han

et al. 2022

Vinyl Additive Technology

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Hydrogenated natural rubber (HNR) was prepared by diimide reduction of natural rubber (NR) latex and characterized by FT‐IR, 1H NMR and TG‐DTG. The thermal degradation kinetic models of HNR were studied under a nitrogen atmosphere by TG‐DTG. Achar and Coats–Redfern methods were used to study the non‐isothermal kinetics models change during the thermal degradation process of NR after hydrogenation. The results indicated that HNR with 34.69% and 63.74% hydrogenation degree were prepared. A one‐stage pyrolysis pathway could be observed from all the TGA curves which were shifted to higher degradation temperatures with the rise of saturation degree. The similar activation energies obtained by both Coats–Redfern and Achar methods confirmed that the kinetics calculation was accurate. The results showed the best‐fit models of the samples with the highest regression coefficient values (R2 > 0.90) were chemical reaction models. The reaction order was three (N3) in NR case and the corresponding mechanism functions were g(α) = [(1‐α)−2–1]/2, f(α) = (1‐α)3. The reaction order was two (N2) when it came to HNR with hydrogenation degree of 34.69%. The most probable mechanism functions were g(α) = (1‐α)−1–1, f(α) = (1‐α)2. As the degree of hydrogenation increased to 63.74%, the reaction order best‐fit changed to one (N1) which was proved to be the same as the ethylene‐propylene diene rubber samples. And the mechanism functions were g(α) = −ln(1‐α), f(α) = 1‐α. The thermal degradation models of polymers was closely related to the structure. And the structure effects affected the degradation behavior as well as the thermal properties of polymers.

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Kinetic analysis and reaction mechanism of p-alkoxybenzyl alcohol ([4-(hydroxymethyl)phenoxymethyl]polystyrene) resin pyrolysis: Revealing new information on thermal stability

Cited by 17 publications

References 59 publications

Kinetics Study of Polypropylene Pyrolysis by Non-Isothermal Thermogravimetric Analysis

Kinetics Study of Polypropylene Pyrolysis by Non-Isothermal Thermogravimetric Analysis

Application of Model-Free and Model-Based Kinetic Methods in Evaluation of Reactions Complexity during Thermo-Oxidative Degradation Process: Case Study of [4-(Hydroxymethyl)phenoxymethyl] Polystyrene Resin

The kinetic models analyses of hydrogenated natural rubber during non‐isothermal degradation process

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