Mechanism of thermal degradation of polyurethanes investigated by direct pyrolysis in the mass spectrometer

Ballistreri, Alberto; Foti, Salvatore; Maravigna, P.; Montaudo, Giorgio; Scamporrino, Emilio

doi:10.1002/pol.1980.170180628

Cited by 88 publications

(31 citation statements)

References 23 publications

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“…It is well known that the N‐alkylation of PU significantly enhances the thermal stability of PU. Ballistreri and coworkers29–31 reported the investigation of the mass spectra of some PUs for examination of the influence of structural factors on the thermal behavior of these polymers and the detection of the possible differences in their degradation products. The mass spectral data showed that the unmodified PUs undergo a quantitative depolycondensation process.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and thermal behavior of poly(ethylene oxide) poly(N‐substituted urethane)

Kweon

Lee

Noh

2001

J. Polym. Sci. A Polym. Chem.

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Poly(N‐substituted urethane)s with an alkyl or ligo(ethylene oxide) monomethyl ether side chain were synthesized by the reaction operating in the following two‐step process: first, by metalation of the starting polymer with potassium tertiary butoxide (t‐BuOK) and then by treatment of the obtained urethane polyanion with tosylate in dimethyl sulfoxide. The thermal properties of poly(ethylene oxide) poly(N‐substituted urethane) (N‐sub PEOPU) were investigated in view of the N‐substitution degree and properties of the substituent. The chemical structures were characterized by Fourier transform infrared, 1H NMR, and 13C NMR spectroscopies. DSC and thermogravimetric analysis (TGA) were used to investigate the thermal properties of N‐sub PEOPUs. As the degree of N‐methylation increased, the glass‐transition temperature (Tg) of the N‐sub PEOPUs linearly decreased from 6 to −29 °C, and the weight‐loss temperature of 5% (T 5%d) from TGA in air increased from 278 to 360 °C. In the fully N‐substituted PEOPUs, the behavior of the thermal decomposition of the PEOPU that was processed in two stages was changed to one‐step decomposition in the temperature range of 360–440 °C. The Tg was shifted to a lower temperature with an increasing length of the substituent in N‐sub PEOPU. Improvement of the thermal stability by N‐substitution was more significant in N‐alkyl PEOPU than in N‐ethoxylate PEOPU. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4129–4138, 2001

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Section: Resultsmentioning

confidence: 99%

Synthesis and thermal behavior of poly(ethylene oxide) poly(N‐substituted urethane)

Kweon

Lee

Noh

2001

J. Polym. Sci. A Polym. Chem.

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“…The thermal degradation of polyurethane materials has been examined by several researchers. 8,[21][22][23] In particular, the composition of polyurethane, that is, the type of isocyanate/ polyol and the chain extender or crosslinker, was found to directly influence the thermal stability, 9 -10,24 -27 and in some cases the degradation curves were proposed as «fingerprint» to identify commercial polyurethanes. 28 -30 In a previous article, the different thermal stabilities of polyether-and polyester-based polyurethanes were measured using the criterion of the required time to reach 5% weight loss during the isothermal experiments.…”

Section: Introductionmentioning

confidence: 99%

Thermooxidative stability of different polyurethanes evaluated by isothermal and dynamic methods

Fambri

Pegoretti

Gavazza

et al. 2001

J of Applied Polymer Sci

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ABSTRACT:Two methods for the evaluation of resistance to the thermooxidation of different classes of polyurethane films (PURs) throughout thermogravimetric analyses were used. Normal and waterborne polyurethanes were characterized using either isothermal or dynamic heating. In the isothermal method, the times required to reach degradations of 0.025, 0.05, and 0.10 were determined at several temperatures in the interval of 190 -250°C. In the dynamic method, heating rates of 0.5, 1, 2, 5, and 10°C /min were used in the range of 30 -500°C, and degradations of 0.025, 0.05, 0.10, 0.20, and 0.40 were considered. From the Arrhenius plots, activation energies were evaluated ranging between 130 and 230 kJ/mol for normal PURs and between 80 and 170 kJ/mol for waterborne PURs depending on the method, temperature interval, and degree of degradation. Advantages and disadvantages of the two methods were compared. The isothermal method requires a preliminary test, and it was more useful for degradation studies up to 0.05. The dynamic method offered evidence for the presence of different degradation processes, and it was more suitable for the evaluation of kinetics parameters at higher degrees of degradation.

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“…The -NH-linkage of secondary amine and olefinic end group in polymer backbone may provide better flame-retardant property. [21] The products formed during combustion process are isocyanate, secondary amine, carbon monoxide (CO), end group of olefinic unit and char unit of pendant aromatic rings. From these information as well as polyurethane degradation-based mechanism, [19] we proposed a mechanism for these nitrogen-based polyacrylamides, shown in Scheme 3.…”

Section: Fire Behavior Of Polymers (Cone Calorimeter Test)mentioning

confidence: 99%

Studies on photocrosslinking and flame‐retardant properties of chalcone‐based polyacrylamides

Boopathy

Subramanian

2015

Polymers for Advanced Techs

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A photocrosslinkable polycyclic chalcone-based acrylamide has been synthesized by Claisen-Schmidt condensation reaction and then polymerized via free radical polymerization technique using azobisisobutyronitrile (AIBN) as an initiator. The resulting polymers have been characterized by FT-IR, 1 H-NMR and 13 C-NMR analytic techniques. The molecular weights of the polymers were determined by gel permeation chromatography. The thermal properties of synthesized polymers were characterized by TGA analysis, and the obtained results show good thermal and thermo-oxidative stability which is required for a negative photo resist. The high flame-retardant properties are calculated from limiting oxygen index (LOI) values and are found to be 36.9 and 32.0 for naphthyl and anthryl chalcone-based polymers, respectively. The experimentally determined LOI values of polymers (PMNPA and PAPA) are 34.3 and 30.2, respectively, and the values are closer to theoretically found LOI values. However, the cone calorimetry of flame-retardant PMNPA only showed a slight decrease in peak of heat release rate (PHRR) and total heat release (THR) compared to PAPA but the ignition time (TTI) of PMNPA is slightly higher than PAPA. The photocrosslinking properties of the polymers were investigated by UV spectroscopy technique and were found that with the increase in number of aromatic rings, the rate of crosslinking decreases. Thus polyacrylamides are useful in photolithography technology as well as flame-retardant property in electrical appliances.

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Mechanism of thermal degradation of polyurethanes investigated by direct pyrolysis in the mass spectrometer

Cited by 88 publications

References 23 publications

Synthesis and thermal behavior of poly(ethylene oxide) poly(N‐substituted urethane)

Synthesis and thermal behavior of poly(ethylene oxide) poly(N‐substituted urethane)

Thermooxidative stability of different polyurethanes evaluated by isothermal and dynamic methods

Studies on photocrosslinking and flame‐retardant properties of chalcone‐based polyacrylamides

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