Nanoclay and carbon nanotubes as potential synergists of an organophosphorus flame-retardant in poly(methyl methacrylate)

Isitman, Nihat Ali
Kaynak, Cevdet
This study explores whether nanoparticles incorporated in polymers always act as synergists of conventional flame-retardant additives. For this purpose, two different filler nanoparticles, namely organically modified layered-silicate clay minerals or nanoclays and multi-walled carbon nanotubes, were incorporated in poly(methyl methacrylate) filled with an organophosphorus flame-retardant that acts through intumescence. Effective dispersion techniques specific to each nanoparticle were utilized and prepared samples were thoroughly characterized for their nanocomposite morphologies. Nanoclays were shown to outperform carbon nanotubes in respect of improving the fire properties of intumescent formulations assessed by cone calorimeter analysis. An intriguing explanation for the observed behaviour was the restriction of intumescence by strong carbon nanotube networks formed on the flaming surfaces during combustion contrary to enhanced intumescent chars by nanoclays. Carbon nanotubes surpassed nanoclays considering the thermal stability of intumescent formulations in thermogravimetry whereas mechanical properties were significantly superior with nanoclays to those with carbon nanotubes.


Nanostructure of montmorillonite barrier layers: A new insight into the mechanism of flammability reduction in polymer nanocomposites
Isitman, Nihat Ali; Kaynak, Cevdet (2011-12-01)
This study describes the mechanism of flammability reduction in flame-retarded polymer matrix organo-montmorillonite reinforced nanocomposites. Morphologies of untested polymer nanocomposites and char residues formed by combustion in the mass loss calorimeter are characterized by XRD and TEM techniques. It is postulated that a combination of well-dispersed montmorillonite platelets and flame retardants in the polymer matrix provides nano-structured char formation. Initial montmorillonite dispersion in flame...
Thermal degradation of organophosphorus flame-retardant poly(methyl methacrylate) nanocomposites containing nanoclay and carbon nanotubes
ORHAN, Tugba; Isitman, Nihat Ali; Hacaloğlu, Jale; Kaynak, Cevdet (2012-03-01)
Filler nanoparticles pave the way for the development of novel halogen-free flame-retardant polymers. The aim of this study was to investigate the thermal degradability, and in particular, the thermal degradation mechanism of organophosphorus flame-retardant poly(methyl methacrylate) (PMMA) nanocomposites containing nanoclay (NC) and multi-walled carbon nanotubes (CNT). For this purpose, thermogravimetry and direct pyrolysis mass spectrometry analysis were utilized. The onset of degradation was delayed thro...
The role of nanoparticle geometry in flame retardancy of polylactide nanocomposites containing aluminium phosphinate
Isitman, Nihat Ali; Doğan, Mehmet Onur; BAYRAMLI, ERDAL; Kaynak, Cevdet (2012-08-01)
Although there is considerable research effort in the development of halogen-free flame-retardant polylactide (PLA), a bio-based aliphatic polyester, the potential synergistic interactions of nanoparticles and conventional additives have scarcely been considered. Therefore, this study aimed to investigate the influence of nanofiller geometry on fire retardancy of PLA nanocomposites containing aluminium diethylphosphinate (AlPi) flame retardant. For this purpose, a variety of nanofiller geometries were utili...
Multi-crystalline silicon solar cells with metal-assisted nano-texturing using HNO3 as hole injection agent
Es, Fırat; Baytemir, Gulsen; Kulakci, Mustafa; Turan, Raşit (2016-12-01)
In this study, metal-assisted etching (MAE) with nitric acid (HNO3) as a hole injecting agent has been employed to texture multi-crystalline silicon wafers. It was previously proven that addition of HNO3 enabled control of surface texturing so as to form nano-cone shaped structures rather than nanowires. The process parameters optimized for optically efficient texturing have been applied to multi-crystalline wafers. Fabrication of p-type Al: BSF cells have been carried out on textured samples with thermal S...
Nano calcium phosphates doped with titanium and fluoride ions: sinterability and stability of phases
Güngör Geridönmez, Serap; Evis, Zafer; Department of Engineering Sciences (2012)
The purpose of this study was to synthesize calcium phosphates doped with titanium and fluoride ions in different combinations. Pure and doped calcium phosphates were synthesized by a precipitation method. The synthesized materials were sintered at 1100ºC and 1300ºC for 1h. The ceramics were characterized by density measurements to determine the effect of sintering temperature. Presence of phases and bonds were characterized by XRD diffraction and FTIR spectroscopy. Grain sizes of the samples were obtained ...
Citation Formats
N. A. Isitman and C. Kaynak, “Nanoclay and carbon nanotubes as potential synergists of an organophosphorus flame-retardant in poly(methyl methacrylate),” POLYMER DEGRADATION AND STABILITY, pp. 1523–1532, 2010, Accessed: 00, 2020. [Online]. Available: