Thermal Degradation of Polystyrene

Kuroki, Takeshi; Honda, T.; Sekiguchi, Yuuki; Ogawa, Taichi; Sawaguchi, Takashi; Ikemura, Tadashi

doi:10.1246/nikkashi.1977.894

Cited by 13 publications

(8 citation statements)

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“…Therefore, the polymers decompose into a large number of paraffinic and olefinic compounds. The analysis of the gaseous and liquid products agrees with the radical chain mechanism proposed by Yan et al [29,37].…”

Section: Resultssupporting

confidence: 88%

“…The H-abstraction can be intermolecular, where a free radical takes a hydrogen from a different molecule, or intramolecular, where the hydrogen abstraction occurs inside in the same radical followed by β-scission which originates an alkene and a free radical. Finally, the termination phase occurs through the combination of two radicals [35][36][37][38][39][40]. The proposed reaction mechanism for PP, HDPE and LDPE are presented in Figure 8.…”

Section: Resultsmentioning

confidence: 99%

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Conversion of PP, HDPE and LDPE Plastics Into Liquid Fuels and Chemical Precursors by Thermal Cracking

Lamar

Noboa

Miranda

et al. 2021

Preprint

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The inappropriate disposal of plastic waste cause serious environmental problems. Nowadays, alternative processes are being studied for the sustainable reutilization of plastics. One of these options is the cracking into shorter liquid hydrocarbon fractions, while maintaining its basic chemical structure. The energetic potential from the original plastics structure remains and the fractions can be used as fuels and chemical precursors. This research addresses the kinetic study of thermal cracking of polypropylene (PP) and high- and low-density polyethylene (HDPE and LDPE) in a batch reactor. The kinetics of the reaction can be described as a first-order rate with the lowest activation energy using PP, followed by HDPE and LDPE with values of 367.28 kJ/mol, 453.37 kJ/mol and 457.96 kJ/mol, respectively. The yield obtained for the liquid fraction is highest for LDPE, with a value of 72% at 390°C, followed by HDPE and LDPE with 69% and 62% at 375°C. The liquid fractions obtained from the process were characterized according to ASTM standards, obtaining that LDPE and HDPE fractions have similar properties to diesel, while PP is closer to gasoline. The fractions were also analyzed by means of gas chromatography identifying the main products of the reaction and establishing a possible reaction mechanism.

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Section: Resultssupporting

confidence: 88%

Section: Resultsmentioning

confidence: 99%

Conversion of PP, HDPE and LDPE Plastics Into Liquid Fuels and Chemical Precursors by Thermal Cracking

Lamar

Noboa

Miranda

et al. 2021

Preprint

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“…As opposed to CZnO, AZnO and FZnO loaded blends demonstrated excellent and impressive thermal stability at even low phr. Due to the decrease in chain mobility caused by the dispersion of nanoparticles into the polymer matrices, the delay in polymer degradation as ZnO nanoparticle content rises in the samples can be explained 41,42 . Because inorganic nanoparticle fillers have very high surface areas and are nondegradable.…”

Section: Resultsmentioning

confidence: 99%

“…Due to the decrease in chain mobility caused by the dispersion of nanoparticles into the polymer matrices, the delay in polymer degradation as ZnO nanoparticle content rises in the samples can be explained. 41,42 Because inorganic nanoparticle fillers have very high surface areas and are nondegradable. The great dispersion of the nanoparticles in the polymer matrix acts as a barrier to the diffusion of the free radical, resulting in a delay in the breakdown of the rubber compounds.…”

Section: Thermal Response Of Blends From Tgamentioning

confidence: 99%

Influence of active, nano, and functionalized zinc oxide particles on the mechanical, cytotoxicity, and thermal stability of carbon black filled SBR/NR blends

Sreethu

Jana

et al. 2023

Polymer Engineering & Sci

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This study examines the viability of functionalized, nano, and active zinc oxide (ZnO) as an alternative activator in styrene butadiene rubber–natural rubber (SBR–NR) blends filled with carbon black. Concerns about the environmental impact and toxicity of Zn leaching into aquatic organisms necessitate reducing the amount of ZnO in rubber compounding. The mechanical properties, crosslink density, and thermal and morphological qualities of the SBR/NR blends made with these ZnO (F2BB, N2BB, and A2BB) were studied and compared to conventional ZnO loaded blend (C5BB). Thermal stability was evaluated using thermogravimetric analysis and temperature scanning stress relaxation. A2BB showed the highest thermal stability, while F2BB exhibited a 35% increase in tensile strength and a 28% increase in elongation at break due to polysulfide linkages. N2BB and A2BB increased tensile strength by 28 and 16% compared to C5BB. Cytotoxicity of various ZnO concentrations on HT‐22 hippocampal cells was investigated, and active and nano ZnO were found to be less toxic. Using active and nano ZnO can improve the mechanical and thermal properties of the blend while reducing environmental toxicity, allowing for a 60% reduction in ZnO concentration in rubber compounds and resulting in cost savings and a sustainable alternative to conventional ZnO.

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“…On the other hand, waste plastics and rubbers can be regarded as a potentially cheap and abundant source for transportation fuels and useful chemicals. Thermodegradation of polymers has been investigated extensively since World War II, − but relatively few studies on the catalytic conversion of polymers have been carried out, especially for production of liquid fuels.…”

Section: Introductionmentioning

confidence: 99%

Depolymerization−Liquefaction of Plastics and Rubbers. 1. Polyethylene, Polypropylene, and Polybutadiene

1997

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The solid superacid-catalyzed depolymerization-liquefaction (DL) reactions of high-density polyethylene (HDPE), isotactic polypropylene (PPR), and cis-polybutadiene (PB) samples were systematically investigated as a function of processing conditions, i.e., temperature (350-450 °C), time (0.5-3.0 h), H 2 pressure (500-2000 psig), catalyst type and concentration, and the presence of solvents. Catalysts used included SO 4 2-/Fe 2 O 3 , SO 4 2-/ZrO 2 , and a Pt-modified SO 4 2-/ ZrO 2 . At temperatures >400 °C, with 1-2 wt % of SO 4 2-/Fe 2 O 3 or SO 4 2-/ZrO 2 as catalyst, there is an overlap of catalytic and noncatalytic, viz. thermal DL, reactions. Under such conditions HDPE yields a liquid product consisting of C 5 -C 30 (mostly C 5 -C 12 ) normal and branched paraffins, accompanied by small amounts of cycloparaffins and olefins. Selective catalytic DL of HDPE was achieved at lower temperature (350 °C) in the presence of 17-33 wt % of SO 4 2-/ZrO 2 or the more active Pt/SO 4 2-/ZrO 2 catalyst, preferably in the presence of a chemically compatible solvent, i.e., n-octadecane. Under such conditions the high-yield (>90 wt %) product predominantly consists of branched paraffins in the gasoline boiling range. PPR, which shows high DL reactivity due to its multiply branched polymeric chain structure, yields a similar gasoline-like mixture of C 5 -C 12 branched paraffins as main product. The change in product composition from HDPE and PPR as a function of temperature and reaction time allows for elucidation of mechanistic aspects of the stepwise DL reactions of these polymers. For HDPE results are rationalized in terms of a carbonium ion mechanism involving extensive skeletal isomerization and attendant β-cleavage reactions leading to low branched paraffins as final products. Results obtained demonstrate that at mild temperatures, under properly designed catalytic conditions, waste HDPE and PRR feeds could be effectively converted into desirable multibranched paraffins which represent potential blending components for reformulated, nonaromatic gasolines.

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Thermal Degradation of Polystyrene

Cited by 13 publications

References 0 publications

Conversion of PP, HDPE and LDPE Plastics Into Liquid Fuels and Chemical Precursors by Thermal Cracking

Conversion of PP, HDPE and LDPE Plastics Into Liquid Fuels and Chemical Precursors by Thermal Cracking

Influence of active, nano, and functionalized zinc oxide particles on the mechanical, cytotoxicity, and thermal stability of carbon black filled SBR/NR blends

Depolymerization−Liquefaction of Plastics and Rubbers. 1. Polyethylene, Polypropylene, and Polybutadiene

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