Investigation of the thermal degradation of polyurea: The effect of ammonium polyphosphate and expandable graphite

Awad, Walid H.; Wilkie, Charles A.

doi:10.1016/j.polymer.2010.03.033

Cited by 138 publications

(106 citation statements)

References 25 publications

Supporting

Mentioning

104

Contrasting

Order By: Relevance

“…Two characteristic decomposition stages were observed. The first was related to degradation of the hard segments and the second to the soft segments [23]. Both degradation stages of pure polyurethane and its composites were characterized by a high peak as a consequence of the intensive emission of volatile products of decomposition (Fig.…”

Section: Thermal Analysismentioning

confidence: 99%

The influence of carbon fillers on the thermal properties of polyurethane foam

Ciecierska

Jurczyk-Kowalska

Bazarnik

et al. 2015

J Therm Anal Calorim

View full text Add to dashboard Cite

The aim of this work was to investigate the influence of different types of carbon filler on the thermal stability and flammability of rigid polyurethane foams. As a filler, multi-walled carbon nanotubes and graphite fakes were used. Scanning electron microscopy was used to observe the structure of foam and dispersion of nanofiller in polymer matrix. Thermal stability of these composites was determined by thermogravimetry analysis. Test was carried out under both nitrogen and air atmosphere. The degradation products were evaluated by thermogravimetry (TG) combined with infrared spectroscopy (TG-IR) measurements. The activation energy was measured by the Flynn-Wall-Ozawa method from the TG curves. Flammability tests like limiting oxygen index and smoke density were also measured. No significant changes in the thermal stability of the composites were observed. The activation energy of sample containing carbon filler increased. Based on TG-IR, one can notice that there were no differences in the emitted volatile products during thermal degradation. Carbon filler enhanced fire retardancy of polyurethane foam; however, graphite gives better results.

show abstract

Section: Thermal Analysismentioning

confidence: 99%

The influence of carbon fillers on the thermal properties of polyurethane foam

Ciecierska

Jurczyk-Kowalska

Bazarnik

et al. 2015

J Therm Anal Calorim

View full text Add to dashboard Cite

show abstract

“…EG can form an intumescent carbonaceous layer at high temperatures and the expanded char can then cover a substrate surface to restrain heat and mass transfer, acting as a vital part in condensedphase ame retardancy. 7,8 However, poor dispersion and interfacial compatibility between EG and matrices sometimes restrict its applications. 9 Under the inuence of ame pressure or heat convection, the "worm-like" char produced by EG can easily fall off the foam surface, which is known as the "popcorn effect".…”

Section: Introductionmentioning

confidence: 99%

Establishment of a highly efficient flame-retardant system for rigid polyurethane foams based on bi-phase flame-retardant actions

et al. 2018

View full text Add to dashboard Cite

Rigid polyurethane foam (PU), one of the most promising wall insulation materials, exhibits high flammability and fire risk. In this work, PU/EG/HQ composites with highly effective flame retardancy were fabricated by adding two kinds of flame retardants, expandable graphite (EG) and 10-(2,5-dihydroxyphenyl)-10-hydro-9-oxa-10-phosphorylphenanthrene-10-oxide (DOPO-HQ), during the synthesis of polyurethane. Thermal stability and flammability were evaluated using the limiting oxygen index (LOI), thermogravimetric analysis (TGA), UL-94 vertical flame results, and cone colorimeter tests. The as-synthesized PU/EG/HQ composites showed a high LOI value, a maximum peak heat release rate (PHRR) value which was decreased by 58.5% and an increased char yield at 800 C. They also achieved UL-94 V-0 classification.SEM and Raman spectra indicated that the "worm-like" intumescent char layer with a graphitized structure and the formed viscous liquid film were vital factors in the enhancement of the flame retardancy of polyurethane foam in the condensed phase. TG-IR results show that the release of toxic volatiles and flammable gases from the PU/EG/HQ samples was remarkably decreased compared with the release from pure PU. This work associates a gas-solid biphase flame retardancy mechanism with the incorporation of two types of flame retardant and presents an effective method for the synthesis of bi-phase flame-retardant polymers.

show abstract

“…5% weight loss of foams obtained from A polyols occurs only at temperature range 210-230 ∘ C ( Table 6). As for DTG curve, one can notice that in case of foams obtained from the polyol component with the highest boron content (Table 6, FA1), 3 extremes occur-the first at 210 ∘ C, the second at 240 ∘ C, and the third one at 315 ∘ C. The first extremum appears due to boron groups' decomposition [24], the second due to carbamate groups' decomposition, and the third one due to urea groups' decomposition [25]. Foams obtained in the presence of PA2 polyols show two DTG curve extremesthe first at 260 ∘ C (simultaneous decomposition of boron and carbamate groups) and the second at 315 ∘ C (Table 6, FA2).…”

Section: Foam Typementioning

confidence: 92%

The Modification of Polyurethane Foams Using New Boroorganic Polyols. II. Polyurethane Foams from Boron-Modified Hydroxypropyl Urea Derivatives

Zarzyka

2014

Polymer-Plastics Technology and Engineering

View full text Add to dashboard Cite

The work focuses on research related to determination of application possibility of new, ecofriendly boroorganic polyols in rigid polyurethane foams production. Polyols were obtained from hydroxypropyl urea derivatives esterified with boric acid and propylene carbonate. The influence of esterification type on properties of polyols and next on polyurethane foams properties was determined. Nitrogen and boron impacts on the foams' properties were discussed, for instance, on their physical, mechanical, and electric properties. Boron presence causes improvement of dimensional stability and thermal stability of polyurethane foams. They can be applied even at temperature 150 ∘ C. Unfortunately, introducing boron in polyurethanes foams affects deterioration of their water absorption, which increases as compared to the foams that do not contain boron. However, presence of both boron and nitrogen determines the decrease of the foams combustibility. Main impact on the decrease combustibility of the obtained foams has nitrogen presence, but in case of proper boron and nitrogen ratio their synergic activity on the combustibility decrease can be easily seen.

show abstract

Investigation of the thermal degradation of polyurea: The effect of ammonium polyphosphate and expandable graphite

Cited by 138 publications

References 25 publications

The influence of carbon fillers on the thermal properties of polyurethane foam

The influence of carbon fillers on the thermal properties of polyurethane foam

Establishment of a highly efficient flame-retardant system for rigid polyurethane foams based on bi-phase flame-retardant actions

The Modification of Polyurethane Foams Using New Boroorganic Polyols. II. Polyurethane Foams from Boron-Modified Hydroxypropyl Urea Derivatives

Contact Info

Product

Resources

About