Continuous-distribution kinetics for degradation of polybutylene terephthalate (PBT) in supercritical methanol

Huang, Jie; Yang, Jing; Chyu, Minking K.; Wang, Qing-Ming; Zhu, Zhaojie

doi:10.1016/j.polymdegradstab.2009.09.011

Cited by 19 publications

(9 citation statements)

References 19 publications

(10 reference statements)

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“…Using surface response methodology, they found that the optimum time, temperature, and mass ratio of methanol to PET in supercritical methanolysis were 112 minutes, 298 C, and 6, respectively. 46 A supercritical fluid above its critical point exhibits a dual behavior: it acts not only like a gas molecule (with a high kinetic energy) but also as a liquid (with large density) 47 ; the critical characteristics of methanol are T c = 512.6 K and P c = 8.09 MPa. 38 The rate of decomposition of PET in the supercritical state is significantly higher than those of when liquid or superheated vapor methanolysis are chosen.…”

Section: Sako Et Al Investigated the Possibility Of Pet Decompositionmentioning

confidence: 99%

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Chemical recycling ofPET: A stepping‐stone toward sustainability

Shojaei

Abtahi

Najafi

2020

Polymers for Advanced Techs

145

113

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This paper focuses explicitly on the chemical approaches involved in the recycling of polyethylene terephthalate (PET). Due to the high rate of consumption as well as nonbiodegradability, PET plays a crucial role as one of the most significant sources of accumulated waste in the landfill which jeopardizes our planet. To address this issue as well as increased environmentally conscious, running out of landfill space, natural resource, and energy conservation, and producing value-added chemicals to use as building block or co-products, the chemical recycling methods have been evolved. Therefore, there has been an attempt to have a comprehensive review of the five types of conventional recycling methods namely hydrolysis, methanolysis, glycolysis, aminolysis, and ammonolysis studied by researchers over the last two decades. In this regard, the influence of diverse depolymerization reaction variables for instance, traditional catalyst, temperature profile, ionic liquid catalysts, phase transfer catalyst, microwave assistance, etc was reported. Moreover, the upsides and downsides of each technique were considered.

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Section: Sako Et Al Investigated the Possibility Of Pet Decompositionmentioning

confidence: 99%

“…A supercritical fluid above its critical point exhibits a dual behavior: it acts not only like a gas molecule (with a high kinetic energy) but also as a liquid (with large density) 47 ; the critical characteristics of methanol are T c = 512.6 K and P c = 8.09 MPa 38 …”

Section: Chemical Recycling Of Petmentioning

confidence: 99%

Chemical recycling ofPET: A stepping‐stone toward sustainability

Shojaei

Abtahi

Najafi

2020

Polymers for Advanced Techs

145

113

View full text Add to dashboard Cite

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“…It's an important replacement of supercritical water in polymer recycling. Especially in the depolymerization of the condensation polymer (such as PET [7,8], PC [9], PBT [10,11]), supercritical methanol not only plays the role of the solvent, but also participates in the scission of the polymer chain as the reactor. Besides excellent transmission characteristic and dissolution characteristic, it also has splendid reaction characteristic.…”

Section: Introductionmentioning

confidence: 99%

Performance of supercritical methanol in polyurethane degradation

Liu

Tang

Zhu

et al. 2016

MATEC Web of Conferences

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Abstract. Polyurethane is a group of block copolymer which is composed of diisocyanate, chain extender, and polyol, including polyurethane foam, polyurethane elastomer, waterborne polyurethane, etc. This research focused on thermoplastic polyurethane elastomer (TPU) which is formed with 4,4'-diphenylmethane diisocyanate(MDI), poly(1,4-butanediol-hexanedioic acid) diolpolyester(PBA) and extended with 1,4-butanediol(BDO). The degradation of TPU was carried out with the help of methanol as the supercritical solvent. The SEM of the reaction residues revealed the process of the depolymerisation. The products were measured by GC-MS and found out to be PBA, BDO and 4,4'-methylene diphenyl carbamate (MDC) which is the methylate of MDI. GC-FID, HPLC-UV and GPC were used to further analysis. The experimental results showed that supercritical methanol performed outstandingly in TPU recycling, it needed lower temperature and shorter time than regular methods. At 230 /70min, over 90% raw materials of TPU could be recovered .

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“…[11] Several researchers [12][13][14][15][16][17][18][19] have studied the mechanism and products of PBT decomposition. Passalacqua et al [12] investigated the mechanism of thermal degradation of PBT between 240 • C and 280 • C and reported that the thermal degradation of PBT at these processing temperatures took place at the ester linkage.…”

Section: Introductionmentioning

confidence: 99%

“…Samperi et al [15] investigated thermal degradation of PBT at the processing temperatures of 270-350 • C and found that cyclic oligomers of PBT, which were formed at temperatures below 290 • C by a ring-chain equilibration mechanism, underwent thermal decomposition at higher temperature by a β-hydrogen transfer mechanism. Huang et al [16] believed that the main reaction products of decomposition of PBT in supercritical methanol were dimethylterephthalate (DMT) and 1,4-butanediol by methanolysis, and the degradation mainly included random scission and chain-end scission reactions and side reactions for monomer components. Carroccio et al [17] compared the thermal-and photo-oxidation processes of PBT and found that two thermal-oxidation processes and two photo-oxidation cleavages were unambiguously ascertained to occur in PBT.…”

Section: Introductionmentioning

confidence: 99%

Thermal Stability and Thermal Degradation Kinetics of Poly(Trimethylene-co-Butylene Terephthalate) Copolymers

Zou

Wang

et al. 2011

Journal of Macromolecular Science, Part B

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The thermal stability and thermal decomposition kinetics of poly(trimethylene-cobutylene terephthalate) (PTBT) copolymers in nitrogen were studied by means of thermogravimetry. The PTBT copolymers had good thermal stability in nitrogen and the introduction of copolymer component had a slight influence on the thermal stability of copolymers. The mass loss of PTBT copolymer was accomplished in one main mass loss stage and one small weight loss in the early stage of decomposition. The PTBT copolymers started to decompose at ≈350.0 • C and completed decomposition at ≈440.0 • C with the heating rate of 5 • C/min. The characteristic degradation temperatures of PTBT copolymers shifted toward higher temperatures with increasing heating rates and poly(trimethylene terephthalate (PTT) content. Furthermore, various degradation methods, including the Ozawa-Flynn-Wall method, Friedman's method, and Kissinger's method, were used to determine the activation energies of copolymers. The three methods were applicable to the kinetic description of thermal degradation of PTBT copolymers. The thermal activation energies obtained by three methods were in satisfactory conformity. The thermal degradation kinetics of copolymers could be interpreted in terms of multi-step degradation mechanisms. It was shown that the thermal stability of PTBT copolymers increased with increase in PTT content. Copolymers with higher PTT content showed higher degradation temperature and thermal activation energy. A general activation energy range of 180-200 kJ/mol was suggested for the processing and use of PTBT copolymer fibers.

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Continuous-distribution kinetics for degradation of polybutylene terephthalate (PBT) in supercritical methanol

Cited by 19 publications

References 19 publications

Chemical recycling ofPET: A stepping‐stone toward sustainability

Chemical recycling ofPET: A stepping‐stone toward sustainability

Performance of supercritical methanol in polyurethane degradation

Thermal Stability and Thermal Degradation Kinetics of Poly(Trimethylene-co-Butylene Terephthalate) Copolymers

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