Degradation Kinetics of Organophosphorus and Organonitrogen Pesticides in Different Waters under Various Environmental Conditions

1995 ◽  
Vol 29 (5) ◽  
pp. 1246-1254 ◽  
Author(s):  
Syvain B. Lartiges ◽  
Philippe P. Garrigues
2015 ◽  
Vol 17 (16) ◽  
pp. 10953-10962 ◽  
Author(s):  
Chengyue Lai ◽  
Yongchun Liu ◽  
Jinzhu Ma ◽  
Qingxin Ma ◽  
Hong He

The degradation kinetics of dehydroabietic acid by OH radicals were investigated under various environmental conditions.


Chemosphere ◽  
2015 ◽  
Vol 119 ◽  
pp. 1075-1083 ◽  
Author(s):  
Lianguo Chen ◽  
Ying Xu ◽  
Wenxiong Wang ◽  
Pei-Yuan Qian

2014 ◽  
Vol 91 ◽  
pp. 32-39 ◽  
Author(s):  
Chengyue Lai ◽  
Yongchun Liu ◽  
Jinzhu Ma ◽  
Qingxin Ma ◽  
Hong He

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 63 ◽  
Author(s):  
Claudia Barile ◽  
Caterina Casavola ◽  
Paramsamy Vimalathithan ◽  
Marco Pugliese ◽  
Vincenzo Maiorano

The present work describes the mechanical characterization combined with the thermal degradation kinetics of Carbon Fiber Reinforced Polymers (CFRP). The thermal degradation kinetics of CFRP have never been studied in the past. In that regard, the present work focuses on studying the thermal degradation kinetics of CFRP tested mechanically at different environmental conditions. Tensile tests were performed on the specimens with different lay-ups at room temperature, elevated temperature (71 °C), and cryogenic conditions (−54 °C), and the same specimens were used for thermal degradation kinetic studies. Mechanical tests show different responses respect to the different environmental conditions and different fibers orientation. On the other hand, the thermogravimetric results, mass loss, and derivative mass loss, show no significant difference in the degradation of CFRP tested at different temperatures. However, the thermal degradation kinetics shows more insight into the degradation pattern of the materials. The activation energy of degradation shows that the degradation of materials subjected to elevated conditions increases rapidly in the later stages of degradation, suggesting the formation of high char yield. The varying activation energy has been related to different degradation mechanisms. Lastly, the morphology of the materials was studied under SEM to understand the structural change in the material after tested in different weather conditions.


2014 ◽  
Vol 131 (11) ◽  
pp. n/a-n/a ◽  
Author(s):  
Marcin K. Heljak ◽  
Wojciech Swieszkowski ◽  
Krzysztof Jan Kurzydlowski

Author(s):  
Zafirah Mahyun ◽  
Noor Fazliani Shoparwe ◽  
Ahmad Zuhairi Abdullah ◽  
Abdul Latif Ahmad ◽  
Mardawani Mohamad ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1597
Author(s):  
Iman Jafari ◽  
Mohamadreza Shakiba ◽  
Fatemeh Khosravi ◽  
Seeram Ramakrishna ◽  
Ehsan Abasi ◽  
...  

The incorporation of nanofillers such as graphene into polymers has shown significant improvements in mechanical characteristics, thermal stability, and conductivity of resulting polymeric nanocomposites. To this aim, the influence of incorporation of graphene nanosheets into ultra-high molecular weight polyethylene (UHMWPE) on the thermal behavior and degradation kinetics of UHMWPE/graphene nanocomposites was investigated. Scanning electron microscopy (SEM) analysis revealed that graphene nanosheets were uniformly spread throughout the UHMWPE’s molecular chains. X-Ray Diffraction (XRD) data posited that the morphology of dispersed graphene sheets in UHMWPE was exfoliated. Non-isothermal differential scanning calorimetry (DSC) studies identified a more pronounced increase in melting temperatures and latent heat of fusions in nanocomposites compared to UHMWPE at lower concentrations of graphene. Thermogravimetric analysis (TGA) and derivative thermogravimetric (DTG) revealed that UHMWPE’s thermal stability has been improved via incorporating graphene nanosheets. Further, degradation kinetics of neat polymer and nanocomposites have been modeled using equations such as Friedman, Ozawa–Flynn–Wall (OFW), Kissinger, and Augis and Bennett’s. The "Model-Fitting Method” showed that the auto-catalytic nth-order mechanism provided a highly consistent and appropriate fit to describe the degradation mechanism of UHMWPE and its graphene nanocomposites. In addition, the calculated activation energy (Ea) of thermal degradation was enhanced by an increase in graphene concentration up to 2.1 wt.%, followed by a decrease in higher graphene content.


2021 ◽  
pp. 100757
Author(s):  
Akshay Sonawane ◽  
O.P. Chauhan ◽  
Shubhankar D. Semwal ◽  
A.D. Semwal

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2872
Author(s):  
Seyed Mohamad Reza Paran ◽  
Ghasem Naderi ◽  
Elnaz Movahedifar ◽  
Maryam Jouyandeh ◽  
Krzysztof Formela ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document