Depolymerization of poly(butylene terephthalate) using high-temperature and high-pressure methanol

Shibata, Mitsuhiro; Masuda, Taiji; Yosomiya, Ryûtoku; Lian, Meng

doi:10.1002/1097-4628(20000929)77:14<3228::aid-app260>3.0.co;2-g

Cited by 13 publications

(5 citation statements)

References 7 publications

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“…When used in composite applications, PBT has cost effective recycling advantages 11 ' 12 . Physiochemical properties and morphology in PBT have been studied by various methods 10 ' 13 " 15 .…”

Section: Pbt Materialsmentioning

confidence: 99%

VARTM & RTM Processing of PBT & PA Thermoplastic Composites

Mallon¹,

Dweib²,

Ziaee³

et al. 2002

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Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information , 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302 Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY) SPONSOR/MONITOR'S ACRONYM(S)ONR SPONSOR/MONITOR'S REPORT NUMBER(S)Not Applicable processes have been successfully developed to enable infusion of thermoplastic prepolymers into glass and carbon fiber performs at temperatures up to 210°C. The prepolymers used in this study were CBT (Cyclic Butylene Teraphthalate oligomer) DISTRIBUTION / AVAILABILITY STATEMENTleading to a PBT composite, APLC-12 (Anionically-Polymerised Lactam -12) leading to a PA-12 composite, and APLC-6 (Anionically-Polymerised Lactam -6) leading to a PA-6 composite. Mixtures of PA-12 and PA-6 were also examined.Traditionally it has not been easy to mold thermoplastic-reinforced composites due to their high viscosities. High temperatures and pressures were always required to fully impregnate fiber beds. Liquid composite molding processes, such as those demonstrated in this report, were virtually impossible. The employment of an activated pre-polymer melts eliminates the problems associated with high viscosity.All of the materials processed here were using vacuum pressure only.For the CBT pre-polymer, a flat heated VARTM mold was used, together with a heated delivery system for transporting the molten resin from the melting unit to the mold. The fiber perform was bagged with a high temperature plastic film and sealing tape. The CBT pre-polymer (supplied by Cyclics Corporation), was melted by heating to 165°C. A catalyst was added just prior to infusion of the catalysed prepolymer into the fiber bed. The viscosity-time characteristics for this material, which polymerized within the mold to form polybutylene terephthalate (PBT), were measured to establish the VARTM processing window. Viscosity values for this material at 160°C varied from 0.1Pa.secs at introduction of the catalyst to 0.5Pa.secs GPa at room temperature to 9 GPa at 150°C for the S2 glass fabric/PBT composite.For the carbon fabric panels, flexural modulii up to 51 GPa were achieved, with flexural strengths of up to 450 MPa.For the PA-12 and PA-6 pre-polymers, a rigid, electrically heated RTM mold was developed. A commercially-available anionic polymerization activator (Grinolit proved to be a quic...

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Section: Pbt Materialsmentioning

confidence: 99%

VARTM & RTM Processing of PBT & PA Thermoplastic Composites

Mallon¹,

Dweib²,

Ziaee³

et al. 2002

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“…Meng and coworkers15, 16 studied the alcoholysis kinetics of poly(butylene terephthalate) (PBT) in supercritical methanol and the effect of the reaction temperature and pressure on the decomposition of PBT. Shibata and Masuda17 reported that the depolymerization of PBT at high temperature was an effective method for the quantitative recovery of dimethyl terephthalate (DMT) and 1,4‐butanediol (BG). Huang and coworkers18, 19 studied the characteristics of the depolymerization of PBT in supercritical methanol.…”

Section: Introductionmentioning

confidence: 99%

Degradation of poly(butylene terephthalate) in different supercritical alcohol solvents

Yang

Huang

Chyu

et al. 2010

J of Applied Polymer Sci

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Reactions were carried out in a batch autoclave reactor. Poly(butylene terephthalate) (PBT) and different alcohol solvents were used in the vessel. The reaction products were analyzed by infrared spectroscopy and gas chromatography/mass spectrometry. Alcoholysis of PBT occurred in supercritical methanol, ethanol, and propanol, and we obtained dimethyl terephthalate (DMT), diethyl terephthalate (DET), and dipropyl terephthalate (DPT), respectively. The conversion of PBT at different temperatures showed similar trends but different degradation degrees. The reactivity for the alcoholysis of PBT in supercritical methanol was much higher than those in supercritical ethanol and propanol. DMT and 1,4-butanediol obtained from the depolymerization of PBT in supercritical methanol reached 98.5 and 72.3%, respectively, at 583 K for 75 min. The yield of DET reached 76% for 75 min.

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“…Catalytic degradation process, therefore, is a more efficient and economical way to recycle feedstock from polymers than by thermal process. Some researchers have been found to study the depolymerization of PBT including methanolysis [2,4], degradation [5][6][7][8], and hydrolysis [9]. Very few of these works, however, were carried out to investigate and compare the results of PBT degradation between thermal and catalytic degradation.…”

Section: Introductionmentioning

confidence: 99%

A comparative study on thermal and catalytic degradation of polybutylene terephthalate

Chiu

2009

Journal of Analytical and Applied Pyrolysis

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Depolymerization of poly(butylene terephthalate) using high-temperature and high-pressure methanol

Cited by 13 publications

References 7 publications

VARTM & RTM Processing of PBT & PA Thermoplastic Composites

VARTM & RTM Processing of PBT & PA Thermoplastic Composites

Degradation of poly(butylene terephthalate) in different supercritical alcohol solvents

A comparative study on thermal and catalytic degradation of polybutylene terephthalate

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