scholarly journals The Toxicological Testing and Thermal Decomposition of Drive and Transport Belts Made of Thermoplastic Multilayer Polymer Materials

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2232 ◽  
Author(s):  
Piotr Krawiec ◽  
Łukasz Warguła ◽  
Daniel Małozięć ◽  
Piotr Kaczmarzyk ◽  
Anna Dziechciarz ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Degradation Kinetics ◽  
Combustion Products ◽  
Polymer Materials ◽  
Toxic Substances ◽  
Butadiene Rubber ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
In Fire ◽  
Kinetics Of

The article presents the potential impact of flat drive and transport belts on people’s safety during a fire. The analysis distinguished belts made of classically used fabric–rubber composite materials reinforced with cord and currently used multilayer polymer composites. Moreover, the products’ multilayers during the thermal decomposition and combustion can be a source of emissions for unpredictable and toxic substances with different concentrations and compositions. In the evaluation of the compared belts, a testing methodology was used to determine the toxicometric indicators (WLC50SM) on the basis of which it was possible to determine the toxicity of thermal decomposition and combustion products in agreement with the standards in force in several countries of the EU and Russia. The analysis was carried out on the basis of the registration of emissions of chemical compounds during the thermal decomposition and combustion of polymer materials at three different temperatures. Moreover, the degradation kinetics of the polymeric belts by using the thermogravimetric (TGA) technique was evaluated. Test results have shown that products of thermal decomposition resulting from the neoprene (NE22), leder leder (LL2), thermoplastic connection (TC), and extra high top cower (XH) belts can be characterized as moderately toxic or toxic. Their toxicity significantly increases with the increasing temperature of thermal decomposition or combustion, especially above 450 °C. The results showed that the belts made of several layers of polyamide can be considered the least toxic in fire conditions. The TGA results showed that NBR/PA/PA/NBR belt made with two layers of polyamide and the acrylonitrile–butadiene rubber has the highest thermal stability in comparison to other belts.

scholarly journals Isothermal Vulcanization and Non-Isothermal Degradation Kinetics of XNBR/Epoxy/XNBR-g-Halloysite Nanotubes (HNT) Nanocomposites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2872
Author(s):  
Seyed Mohamad Reza Paran ◽  
Ghasem Naderi ◽  
Elnaz Movahedifar ◽  
Maryam Jouyandeh ◽  
Krzysztof Formela ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Degradation Kinetics ◽  
Halloysite Nanotubes ◽  
Butadiene Rubber ◽  
Order Model ◽  
Scanning Calorimetry ◽  
Theoretical Methods ◽  
Vulcanization Kinetics ◽  
Kinetics Of ◽  
Thermal Stability Of

The effect of several concentrations of carboxylated nitrile butadiene rubber (XNBR) functionalized halloysite nanotubes (XHNTs) on the vulcanization and degradation kinetics of XNBR/epoxy compounds were evaluated using experimental and theoretical methods. The isothermal vulcanization kinetics were studied at various temperatures by rheometry and differential scanning calorimetry (DSC). The results obtained indicated that the nth order model could not accurately predict the curing performance. However, the autocatalytic approach can be used to estimate the vulcanization reaction mechanism of XNBR/epoxy/XHNTs nanocomposites. The kinetic parameters related to the degradation of XNBR/epoxy/XHNTs nanocomposites were also assessed using thermogravimetric analysis (TGA). TGA measurements suggested that the grafted nanotubes strongly enhanced the thermal stability of the nanocomposite.

scholarly journals Degradation Kinetics of Anthocyanins in Shalgam Beverage

2019 ◽  
Vol 7 (2) ◽  
pp. 282
Author(s):  
Adnan Bozdoğan ◽  
Kurban Yaşar
Keyword(s):  
Activation Energy ◽  
Reaction Kinetics ◽  
Half Life ◽  
Degradation Kinetics ◽  
Production Method ◽  
Order Reaction ◽  
Different Temperatures ◽  
Traditional Production ◽  
Effects Of Temperature ◽  
Kinetics Of

This research was performed to elucidate the effects of temperature on the degradation kinetics of anthocyanins in shalgam beverage. Shalgam beverage was produced according to traditional production method. Then, it was kept at three different temperatures (65°C, 75°C, and 85°C) for 12 hours, and the relevant quantities of anthocyanins were determined thereafter. The research revealed that degradation of the anthocyanins was well described with a 1st-order reaction kinetics model and the R2 values varied in the range of 0.9059-0.9715. Activation energy of the reaction was determined to be 48537 Joule/mole. The half-lives of anthocyanins at 65°C and 75° C, and 85°C were found to be 138.63, 136.72, and 51.57, respectively. Compared the half-life periods at different temperatures, anthocyanins were found to be more resistant at 65°C and 75°C than at 85°C.

Transport kinetics of methanol in hydroxyethyl methacrylate homopolymer and its copolymers

2004 ◽  
Vol 19 (11) ◽  
pp. 3359-3363 ◽  
Author(s):  
C-S. Tsai ◽  
Sanboh Lee ◽  
Tinh Nguyen
Keyword(s):  
Continuous Phase ◽  
Transport Processes ◽  
Hydroxyethyl Methacrylate ◽  
Nominal Thickness ◽  
Methacrylate Copolymers ◽  
Different Temperatures ◽  
Free Energy Of Mixing ◽  
D Values ◽  
Increasing Temperature ◽  
Kinetics Of

The kinetics of methanol transport in 2-hydroxyethyl methacrylate (HEMA) homopolymer and 75/25 and 50/50 mol fraction HEMA/DHPMA (2,3-dihydroxypropyl methacrylate) copolymers at five different temperatures has been investigated using the sorption experiment technique. A combined case I and case II diffusion model was used to describe the transport processes. Four replicates for each temperature of each material having a nominal thickness of 0.1 mm were immersed in methanol maintained at 35, 40, 45, 50, and 55 °C, and the mass uptake as a function of time was measured gravimetrically. Experimental results are found to be in good agreement with model prediction at all temperatures and for all three materials. Both the diffusion coefficients of case I transport and velocity of case II transport increase with increasing temperature. D values at low temperatures (35 and 40 °C), which are in the 10−9 cm2/s range, of the HEMA homopolymer are less than those of the copolymers. On the other hand, the activation energies of case I transport of the copolymers are substantially higher than those of the HEMA homopolymer; however, the level of DHPMA loading in the copolymer does not seem to affect the activation energy. In addition, thermodynamic heat and free energy of mixing values indicate heat is released when HEMA/DHPMA copolymers are exposed to methanol and that the solvent/copolymer systems exist as a continuous phase. In contrast, the methanol/HEMA homopolymer system exists as separate phases.

scholarly journals Synthesis and Thermal Degradation Kinetics of Co(II), Ni(II), Cd(II), Zn(II), Pd(II), Rh(III) and Ru(III) Complexes with Methylquinolino[3,2-b]benzodiazepine

2007 ◽  
Vol 4 (2) ◽  
pp. 199-207
Author(s):  
Bennehalli Basavaraju ◽  
Halehatti S. Bhojya Naik
Keyword(s):  
Thermal Decomposition ◽  
Thermal Degradation ◽  
Elemental Analysis ◽  
Degradation Kinetics ◽  
Transition Metal Ions ◽  
Thermal Degradation Kinetics ◽  
Conductivity Measurements ◽  
Tg Studies ◽  
Kinetics Of ◽  
Kinetics And Thermodynamic

A series of new complexes formed by the interaction of a new ligand Methylquinolino[3,2-b]benzodiazepine (L) with various transition metal ions have been isolated and characterized by elemental analysis and electronic, IR, magnetic moment and conductivity measurements. Thermogravimetric (TG) studies of the complexes have been performed in order to establish the mode of their thermal degradation. The thermal degradation was found to proceed in two steps. The kinetics and thermodynamic parameters were computed from the thermal decomposition data.

Hollow Hemisphere Shell Formation by Pure Kirkendall Porosity

2014 ◽  
Vol 1 ◽  
pp. 61-73 ◽  
Author(s):  
Csaba Cserháti ◽  
Györgyi Glodán ◽  
Dezső L. Beke
Keyword(s):  
Void Formation ◽  
Solid State Reactions ◽  
Average Composition ◽  
Transmission Electron ◽  
Straight Line ◽  
Theoretical Predictions ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Kirkendall Porosity

Nanoshell formation has been studied experimentally in Ag/Au and Ag/Pd systems in a hemispherical geometry at different temperatures. The void formation in these systems is the result ofpureKirkendall-porosity formation, because it is caused mainly by the inequality of the intrinsic atomic fluxes and other effects (e.g. stresses), inevitably present during nanoshell formations in solid state reactions (oxides, sulphides), can be less important or can be neglected. The kinetics of the process was followed by Transmission Electron Microscopy. Both the growth and shrinkage regimes of the process were observed at the same temperature and even the temperature dependence of the characteristic time (tcr) describing the crossover of the two different regimes was observed. We succeeded to show that tcrshifts to smaller values with increasing temperature. This confirms the theoretical results:the growth and the shrinkage regimes are controlled by the faster as well as the slower diffusion coefficients (DAas well as DB), respectively. It is also illustrated that, confirming recent theoretical predictions, the pore radius linearly depends on the initial particle radius and the slope of this straight line increases with the average composition of the faster component.

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