Thermal decomposition study using FTIR

As reported, the thermal decomposition behaviour of amino trimethylene phosphonic acid (ATMP) and l-hydro)yethylidene-l,l-diphosphonic acid (HEDP) have been studied and a comparison of the experimental results from thermal decomposition by TGA-FTIR and pyrolysis GC-MS, together with modelling of the formation reactions, showed the usefulness of the latter method in predicting the possible decomposition products. Thus, pyrolysis GC-MS was used to determine the gaseous decomposition products of ATMP and HEDP at temperatures corresponding to the main decomposition steps detected by TGA-FTIR spectroscopy and, from a comparison of the experimental results with theoretical modelling, it was established that the decomposition process should follow the formation mechanism, i.e. the thermal decomposition can be understood as the reverse reaction of phosphonic acids. 

A recent study on the stability of various indium alkyl derivatives has been performed using differential scanning calorimetry (DSC), which provides a comprehensive thermal fingerprint of the compounds. In addition, when this method of thermal analyses is used in conjunction with thermogravimetric analysis coupled to FTIR and/or GCMS evolved gas analysis, it can provide a complete mechanism for the decomposition pathway of prospective compounds. ... 

Conversion of the as-deposited film into the crystalline state has been carried out by a variety of methods. The most typical approach is a two-step heat treatment process involving separate low-temperature pyrolysis ( 300 to 350°C) and high-temperature ( 550 to 750°C) crystallization anneals. The times and temperatures utilized depend upon precursor chemistry, film composition, and layer thickness. At the laboratory scale, the pyrolysis step is most often carried out by simply placing the film on a hot plate that has been preset to the desired temperature. Nearly always, pyrolysis conditions are chosen based on the thermal decomposition behavior of powders derived from the same solution chemistry. Thermal gravimetric analysis (TGA) is normally employed for these studies, and while this approach seems less than ideal, it has proved reasonably effective. A few investigators have studied organic pyrolysis in thin films by Fourier transform infrared spectroscopy (FTIR) using reflectance techniques. - This approach allows for an in situ determination of film pyrolysis behavior. 

This paper reports a study to verify the relationship between functional group distribution and thermal decomposition behavior. A Fourier transform infrared spectrometer (FTIR) has been employed to obtain quantitative infrared spectra of the coals, chars, and tars produced in the devolatilization experiments. The spectra have been deconvoluted by using a computerized spectral synthesis routine to obtain functional group distributions, which are compared to the model parameters. 

Fourteen chelates of the type [Ni(II)(Diox.H)2], ((Diox.H)2 various a-dioximes) have been studied by means of FTIR, NMR, MS data and various thermoanalytical methods (TG, DTA, DTG, DSC) [210]. In some cases kinetic parameters of the thermal decomposition of the complexes were also calculated using Zsakd s nomogram method . 

The thermal decomposition of 2-CEES on nanocrystalhne zeohtes was probed by FTIR spectroscopy. Comparison of the reactivy of nanocrystaUine NaZSM-5, silicalite and NaY indicated that NaZSM-5 was most effective for 2-CEES thermal oxidation and that external surface silanol sites were important to the zeolite reactivity. The adsorption and reaction of DMMP on nanocrystalline NaY was investigated using FTIR and sohd state NMR spectroscopy. External surface silanol and EFAL sites were implicated in the thermal oxidation of DMMP on nanocrystaUine NaY. Thus, the nanocrystalline zeolites can be envisioned as new bifunctional catalyst materials with active sites on the external surface playing an important role in the intrinsic reactivity of the material. Future studies will focus on optimizing the activity of nanocrystaUine zeolites for CWA decontamination apphcations by taUoring the surface properties. 

The ehemieal reaction of zinc dithiophosphate has been studied using in situ ATR FTIR spectroscopy as well as with imaging XPS and ToF-SIMS. In situ ATR FTIR confirms the existence of a decomposition pathway that proceeds through the elimination of alkanes under pure thermal conditions. The reaetion product is zinc polyphosphate. Under conditions of mild mechanical stress at high temperatures, as well... 

In the present study, TG-FTIR analysis was conducted to investigate the thermal degradation behavior as well as the weight loss rate of KL and LGC. Apart from that, this analysis was carried out using Thermal Analyzer, model TGA/SDTA 851 fitted with Fourier Transform Infrared (Mettler Toledo) in order to analyze the evolved gases that result from the thermal decomposition of samples. The samples were heated from 30-900°C at the heating flow rate of 2 0° C/min in nitrogen gas at the flow rate of 30 mL/min. 

By using combined TGA/FTIR thermogravimetric analysis, accurate real time qualitative and quantitative data can be obtained for thermal decomposition of polymers. It was used to study interactions between an additive and a filler (talc), highlighting a degradation phenomenon of additive by talc, and this phenomenon depended on the structure and chemical composition of talc. This procedure also appUed to analysis of degradation of other additives by talc. Thus, polymer formulations will rapidly be optimised in various areas of filled polymers. 12 refs. 

The objectives of the study carried out by Turk and co-workers [15] were to rank polymer thermo-oxidative stability via accelerated thermal techniques and to correlate these results with the long-term, high-temperature stabilities found via weight loss techniques. In particular, they used TGA, IGA, TGA-FTIR and IGA-FTIR to characterise the degradation pathways of four thermally stable PI and to determine their E. Three accepted mathematical methods were used to examine for correlations of accelerated ageing and real-life ageing of PI. Acceleration of the decomposition is obtained using elevated temperatures that can introduce additional decomposition mechanisms when compared with actual use temperatures. 

Other studies have investigated the decomposition of PMMA utilising TG and calorimetry. One study concentrated on polymer layered silicate nanocomposites 825036 and compared the degradation profiles of PMMA-filled nanocomposites to that of pure PMMA by using TG-DSC-FTIR and GC-MS. The results based on TG and DSC indicated enhanced thermal stability and higher glass transition temperature of filled PMMA nanocomposites with respect to that of pure PMMA. Nonetheless, in both cases the decomposition was described as a two-step reaction. 

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