Thermooxidative stabilization of a MDI

Albu

et al. 2015

J Therm Anal Calorim

Self Cite

This study presents the synthesis of polyesters obtained from phthalic anhydride as acidic components and one mixture of monoethylene glycol and monohydric alcohol (in ratio 1.1:0.15). Molar ratio of the acid component and alcohol component was 1:1.25. n-Propanol, n-butanol, n-octanol and isoamyl alcohol were used as monohydric alcohol. Physicochemical characterization was performed by elemental analysis, FTIR/UATR spectroscopy of polyesters and char, EGA (evolved gas analysis), thermal analysis in synthetic air and in nitrogen atmosphere.

Section: Methodsmentioning

confidence: 99%

Influence of the nature of the chain breaker on the thermal stability of phthalic anhydride-based polyesters

Modra

Albu

et al. 2015

J Therm Anal Calorim

Self Cite

“…The time technical norm N t of a machining operation in a metal cutting process is presented in the specialized literature [6] as the following function: The machining time t b for the drilling operation can be written as:…”

Section: Determination Of the Productivity Of The Drilling Operationmentioning

confidence: 99%

“…where k 1 is a constant chosen from normative tables. The rest and natural necessities time t on is calculated by the relation [6]:…”

Section: Determination Of the Productivity Of The Drilling Operationmentioning

confidence: 99%

“…The constants .031 0 = f C and .9 0 = s k were chosen from the specialized literature (tab.6.10 and tab.6.11 in [6]). The values of the constants and polytropic coefficients for the drilling of the stainless steel 10TiMoNiCr175 were determined based on the experimental measurements: C F = 2.52; x F = 0.79; y F = 0.32; z F = -0.25; C M = 4.2; x M = 1.20; y M = 0.42; z M = -0.14 from [7].…”

Section: Case Study For the Drilling Of The Stainless Steel 10timonic...mentioning

confidence: 99%

See 1 more Smart Citation

Optimization of the Tool Life and the Cutting Speed in Terms of Productivity at Drilling of the Stainless Steel 10TiMoNiCr175

Blăjină

2013

AMM

The stainless steels are used more and more in various key domains of the technique [. The processing of these steels is determined by their specific physical-chemical characteristics and by their technological properties [2, 3]. The research in the last decade regarding the cutting machinability of the stainless steels have highlighted the insufficiency of the data for establishing of the optimum cutting processing conditions and the optimum cutting regime [4, 5]. With this object in view, the purpose of this paper is the optimization of the tool life and the cutting speed at the drilling of the stainless steels, in terms of the global indicator of the maximum productivity.

“…The kinetics of the thermal removal (decomposition) of CTMAB has been studied by the non-parametric kinetics (NPK) method of Serra et al 7−9 The NPK method has been applied in recent years for the kinetic analysis of thermal degradation in a variety of chemical systems, e.g., bis-urethanes, 10 transition metal carboxylates, 11 alkaline metal phosphates 12 and glutamates, 13 alkaline metal and alkaline-earth metal benzoates, 13 and a 3-D zincophosphate containing occluded ammonium species. 14…”

Section: Introductionmentioning

confidence: 99%

A kinetic study of the thermal degradation of cetyl-trimethylammonium bromide inside the mesoporous SBA-3 molecular sieve

Rajić

Stojaković

Mrak

et al. 2008

The thermal degradation of cetyltrimethylammonium bromide (CTMAB) inside the mesoporous SBA-3 was studied under non-isothermal conditions. There are two distinct and complex kinetic processes which partly overlap, each consisting of one dominant and three minor individual processes. The two dominant processes can be described by the Sestak-Berggren model. The main decomposition step (the first dominant process) involves the overcoming of weak interactions between CTMAB and the silica network and proceeds with a lower E a value (116±2 kJ mol-1) than the second dominant process (153±5 kJ mol-1), which can be explained by the size reduction of the pore openings due to the contraction of the SBA-3 unit cell caused by the removal of CTMAB.