Migration Characteristics and Degradation Kinetics of Bisphenol A

2016 ◽  
Vol 850 ◽  
pp. 128-136
Author(s):  
Zhuo Jun Sun ◽  
Jian Gao ◽  
Hui Liu ◽  
Shu Zhen Pan ◽  
Shu Li Zhang ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Bisphenol A ◽  
Aging Time ◽  
Degradation Kinetics ◽  
Heat Stability ◽  
Gas Chromatography Mass Spectrometry ◽  
Oxidative Aging ◽  
Before And After ◽  
Thermal Oxidative Aging ◽  
Kinetics Of

This paper study the migration characteristics and degradation kinetics of bisphenol A using TGA - gas chromatography - mass spectrometry and found that bisphenol A polycarbonate in the thermal oxidative aging conditions of 130 °C de-gradated to bisphenol A. At the range of 0 h to 120 h, the bisphenol A content of environmental hormones increased with time. When it reached 120 h, bisphenol A environmental hormone content decreased slightly with aging time. The content of bisphenol A reached 495mg/kg when the thermal oxidative aging time was 168 h, which was decreased compared to the content of 442mg/kg at 120 h. Polycarbonate thermal decomposition kinetics study showed that the thermal decomposition of polycarbonate can be divided into three phases. The first thermal decomposition occurred at the range of 415° C to 425 ° C, the polycarbonate end groups fracture of the second stage at 493.6°C , the main fracture of the main chain rearrangement and crosslinking, and the third stage at 598.7°C, the degradation of the chain continues to decompose and the decomposition of the crosslinked carbon precursor; thermal oxidation aging of polycarbonate decreased the heat stability and promote the thermal decomposition of polycarbonate. Comparing the oxidation induction period, thermal weight loss rate and activation energy of polycarbonate before and after thermal oxidative aging, it c found that the thermal stability of the hot oxygen aging of polycarbonate is reduced.

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.

Effect of Thermal-Oxidative Aging on the Mechanical Properties of Carbon Fiber Reinforced Bis-Maleimide Composites

2010 ◽  
Vol 152-153 ◽  
pp. 829-833 ◽  
Author(s):  
Xin Ying Lv ◽  
Rong Guo Wang ◽  
Wen Bo Liu ◽  
Long Jiang
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Aging Time ◽  
Testing Temperature ◽  
Fiber Reinforced ◽  
Oxidative Aging ◽  
Fiber Reinforced Polymer Composites ◽  
Carbon Fiber Reinforced ◽  
Thermal Oxidative Aging

Bis-maleimide (BMI) resins are widely applied in carbon fiber reinforced polymer composites in aerospace fields, for their excellent thermal and mechanical properties. The effects of thermo-oxidative aging on mechanical properties of carbon fiber reinforced BMI composites were investigated by SEM with the combination of flexural strength test and inter-laminar shear strength (ILSS) test. The results indicated that the thermal-oxidative aging had some effects on mechanical properties of carbon fiber/BMI composites; however the testing temperature or service temperature had much more effects than aging time. With aging time increased, the flexural strength at 150 oC and the ILSS at 25 oC slightly increased, while the ILSS at 150 oC decreased gradually. Both test results of mechanical properties and fracture models of damaged flexural specimens by SEM indicated that the matrix resin in the composites showed some viscoelastic behaviors that resulted in the remarkable dependence of mechanical properties of the composites on temperature. Therefore, the carbon fiber reinforced BMI composites had lower flexural strength and ILSS at 150 oC than that at 25 oC.

Investigation of physical properties and morphology of compatibilized EPDM/EVA blends

2017 ◽  
Vol 31 (3) ◽  
pp. 376-391 ◽  
Author(s):  
Aman I Khalaf ◽  
Azza A Ward ◽  
Nehad N Rozik
Keyword(s):  
Vinyl Acetate ◽  
Ethylene Vinyl Acetate ◽  
Elongation At Break ◽  
Oxidative Aging ◽  
Itaconic Anhydride ◽  
Aging Resistance ◽  
Before And After ◽  
Time Periods ◽  
Poly Ethylene ◽  
Thermal Oxidative Aging

The main aim is to investigate the effect of adding of 5% hydrolyzed poly (ethylene-co-vinyl acetate) (EVAOH), itaconic anhydride (naturally obtained during fermentation of sugars (It.anhydride)), and mercapto-modified ethylene-co-vinyl acetate (EVASH) as compatibilizers on the mechanical properties before and after thermal oxidative aging at 90°C for different time periods up to 7 days, electrical properties, and morphology of ethylene propylene diene monomer/ethylene vinyl acetate (EPDM/EVA) blends of different compositions (75/25, 60/40, 50/50, and 25/75, respectively). Stress at yield, tensile strength, and elongation at break of EPDM/EVA were improved markedly by the addition of 5% compatibilizers (EVAOH, It.anhydride, and EVASH). The micrographs of fractured surfaces obtained from the scanning electron microscope demonstrated further the enhancement of compatibility between EPDM and EVA by the addition of reactive compatibilizers. Further, the blends permittivity ε′ and dielectric loss ε″ have been measured at specific temperatures. The dielectric properties revealed that It.anhydride and EVASH/EPDM/EVA compositions are promising materials for insulation purposes. Finally, aging resistance was improved by the use of compatibilizers.

scholarly journals Combustion properties and thermal decomposition kinetics of flame retardant silk fabrics treated by phytic acid and silica sols

2018 ◽  
Vol 22 (4) ◽  
pp. 1665-1671 ◽  
Author(s):  
Yun-Bo Chen ◽  
Chun Liu ◽  
Shao-Li Zhang ◽  
Guo-Qiang Chen ◽  
Tie-Ling Xing
Keyword(s):  
Thermal Decomposition ◽  
Flame Retardant ◽  
Phytic Acid ◽  
Kinetics Model ◽  
Combustion Properties ◽  
Before And After ◽  
Combustion Experiment ◽  
Silk Fabrics ◽  
Silica Sols ◽  
Kinetics Of

In order to obtain the flame retardant silk fabric, silica sols and phytic acid were prepared and applied to the silk fabrics. Vertical combustion experiment, thermogravimetric analysis, Fourier transform infrared spectra and smoke density test were used to investigate the combustion behavior, thermal property, and kinetics model of silk fabrics before and after flame retardant finish. The results showed that the sol coating on silk fabrics could increase the carbon residue and hinder the spread of flame when burning, and the tensile strength of treated silk was slightly damaged. Furthermore, the kinetics model of silk thermal decomposition conformed to Avrami-Erofeev model.

scholarly journals Improvements of Developed Graphite Based Composite Anti-Aging Agent on Thermal Aging Properties of Asphalt

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4005 ◽  
Author(s):  
Zhihui Hu ◽  
Tao Xu ◽  
Pengfei Liu ◽  
Markus Oeser ◽  
Haopeng Wang
Keyword(s):  
Thermal Stability ◽  
Synergetic Effect ◽  
Expanded Graphite ◽  
Scanning Calorimetry ◽  
Chain Reactions ◽  
Oxidative Aging ◽  
Caco3 Nanoparticles ◽  
Before And After ◽  
Light Components ◽  
Thermal Oxidative Aging

To reduce the thermal-oxidative aging of asphalt and the release amount of harmful volatiles during the construction of asphalt pavement, a new composite anti-aging agent was developed. Since the volatiles were mainly released from saturates and aromatics during the thermal-oxidative aging of asphalt, expanded graphite (EG) was selected as a stabilizing agent to load magnesium hydroxide (MH) and calcium carbonate (CaCO3) nanoparticles for preparing the anti-aging agents of saturates and aromatics, respectively. Thermal stability and volatile constituents released from saturates and aromatics before and after the thermal-oxidative aging were characterized using the isothermal Thermogravimetry/Differential Scanning Calorimetry-Fourier Transform Infrared Spectrometer test (TG/DSC-FTIR test). Test results indicate that anti-aging agents of EG/MH and EG/CaCO3 effectively inhibit the volatilization of light components in asphalt and improve the thermal stability of saturates and aromatics. Then, the proportions of EG, MH, and CaCO3 added in the developed composite anti-aging agent of EG/MH/CaCO3 are 2:1:3 by weight. EG/MH/CaCO3 plays a synergetic effect on inhibiting the thermal-oxidative aging of asphalt, and reduces the release amount of harmful volatiles during the thermal-oxidative aging after EG/MH/CaCO3 is added into asphalt at the proposed content of 10 wt.%. EG plays a synergistic role with MH and CaCO3 nanoparticles to prevent the chain reactions, inhibiting the thermal-oxidative aging of asphalt.

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.

Study on Aging Resistance Properties of Natural Rubber Dried by Microwave

2013 ◽  
Vol 706-708 ◽  
pp. 266-269
Author(s):  
Yong Zhou Wang ◽  
Fu Quan Zhang ◽  
Mao Fang Huang ◽  
Mei Chen ◽  
Hong Xing Gui ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Oxidative Degradation ◽  
Rate Of Change ◽  
Thermal Oxidative Degradation ◽  
Oxidative Aging ◽  
Degradation Temperature ◽  
Hot Air ◽  
Aging Resistance ◽  
Before And After ◽  
Thermal Oxidative Aging

In this work, thermogravimetry (TG) and Wallace plastometer were used to study the thermal-oxidative aging resistance properties of natural rubber (NR) dried by microwave and hot-air. Showed from the results, thermal degradation temperature, primary thermal-oxidative degradation temperature, the value of P0, PRI and VR for NR dried by microwave were higher than those of NR dried by hot-air; the thermal-oxidative aging resistance properties of NR vulcanizes dried by microwave improved significantly, and the rate of change for elongation at break (-26.76%) and tensile strength (-38.6%) of NR vulcanizes dried by microwave before and after aging were apparently higher than those of NR vulcanizes dried by hot-air, which were (-60.29%) and (-82.11), respectively.

Sign in / Sign up

Export Citation Format

Share Document