Thermal degradation of epoxy resin grafted with polyurethane

2014 ◽  
Vol 21 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Zhenjiang Song ◽  
Jianliang Xie ◽  
Peiheng Zhou ◽  
Jianing Peng ◽  
Xin Wang ◽  
...  

AbstractEpoxy resin grafted with polyurethane was synthesized and characterized through a series of tests. The grafting reactive process between the pendant secondary hydroxyl groups on the side chains of epoxy resin and the isocyanate groups of pre-polyurethane were investigated by Fourier transform infrared spectroscopy. Thermal behavior of the grafted epoxy resin was investigated by thermogravimetric analysis within 40–500°C. The degradation of grafted epoxy resin involved two stages. Microstructures of the polyurethane section and grafted epoxy resin were observed by field emission scanning electron microscopy. Model fitting method was employed to calculate the thermal degradation model of grafted epoxy resin. In this paper, 15 typical kinetic mechanisms were introduced into the model fitting method, such as Coats-Redfern method and Achar-Brindley-Sharp-Wendworth method, to obtain the kinetic function of thermal degradation for grafted epoxy resin.

2020 ◽  
Vol 38 (11) ◽  
pp. 1259-1268
Author(s):  
NL Panwar ◽  
Bhautik Gajera ◽  
Sudhir Jain ◽  
BL Salvi

The pyrolysis and co-pyrolysis behaviours of cotton stalk (CS), torrefied cotton stalk (TCS) and mined coal, as single fuels, and their blends, have been examined through thermogravimetric analysis. Biomass has been torrefied at 250°C for 45 min to enhance physicochemical properties, and then mixed with mined coal for co-pyrolysis. Thermal degradation of CS and TCS is characterized by a reaction. However, this is not the case for mined coal, which shows a single-stage reaction. The thermal degradation of all blends was done in three stages: dehydration; biomass and small mined coal; and lignin or mined coal. A similar trend emerged for mass loss of individual fuels, which depended mainly on their ratios in the blend. The kinetics of pyrolysis and co-pyrolysis of all fuels were calculated at 20°Cmin−1 heating rate using the Coats−Redfern model-fitting method.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2080 ◽  
Author(s):  
Ru Zhou ◽  
Biqing Huang ◽  
Yanming Ding ◽  
Wenjuan Li ◽  
Jingjing Mu

Chlorinated polyvinyl chloride (CPVC), as a new type of engineering plastic waste, has been used widely due to its good heat resistance, mechanical properties and corrosion resistance, while it has become an important part of solid waste. The pyrolysis behaviors of CPVC waste were analyzed based on thermogravimetric experiments to explore its reaction mechanism. Compared with polyvinyl chloride (PVC) pyrolysis, CPVC pyrolysis mechanism was divided into two stages and speculated to be dominated by the dehydrochlorination and cyclization/aromatization processes. A common model-free method, Flynn-Wall-Ozawa method, was applied to estimate the activation energy values at different conversion rates. Meanwhile, a typical model-fitting method, Coats-Redfern method, was used to predict the possible reaction model by the comparison of activation energy obtained from model-free method, thereby the first order reaction-order model and fourth order reaction-order model were established corresponding to these two stages. Eventually, based on the initial kinetic parameter values computed by model-free method and reaction model established by model-fitting method, kinetic parameters were optimized by Shuffled Complex Evolution algorithm and further applied to predict the CPVC pyrolysis behaviors during the whole temperature range.


2021 ◽  
Vol 13 (13) ◽  
pp. 7484
Author(s):  
Gabriel Fernando García Sánchez ◽  
Rolando Enrique Guzmán López ◽  
Roberto Alonso Gonzalez-Lezcano

Buildings consume a large amount of energy during all stages of their life cycle. One of the most efficient ways to reduce their consumption is to use thermal insulation materials; however, these generally have negative effects on the environment and human health. Bio-insulations are presented as a good alternative solution to this problem, thus motivating the study of the properties of natural or recycled materials that could reduce energy consumption in buildings. Fique is a very important crop in Colombia. In order to contribute to our knowledge of the properties of its fibers as a thermal insulator, the measurement of its thermal conductivity is reported herein, employing equipment designed according to the ASTM C 177 standard and a kinetic study of its thermal decomposition from thermogravimetric data through the Coats–Redfern model-fitting method.


2021 ◽  
Author(s):  
Guillaume Gerandi ◽  
Virginie Tihay‐Felicelli ◽  
Frederic Morandini ◽  
Paul‐Antoine Santoni

2014 ◽  
Vol 1053 ◽  
pp. 263-267 ◽  
Author(s):  
Xiu Juan Tian

Thermal stability and thermal degradation kinetics of epoxy resins with 2-(Diphenylphosphinyl)-1, 4-benzenediol were investegated by thermogravimetric analysis (TGA) at different heating rates of 5 K/min, 10 K/min, 20 K/min and 40 K/min. The thermal degradation kinetic mechanism and models of the modified epoxy resins were determined by Coast Redfern method.The results showed that epoxy resins modified with the flame retardant had more thermal stability than pure epoxy resin. The solid-state decomposition mechanism of epoxy resin and the modified epoxy resin corresponded to the controlled decelerating ځ˽̈́˰̵̳͂͆ͅ˼˰̴̱̾˰̸̵̈́˰̵̸̳̱̹̽̾̓̽˰̶̳̹̾̈́̿̾̓ͅ˰̶˸ځ˹˰̵̵͇͂˰̃˸́˽ځ˹2/3. The introduction of phosphorus-containing flame retardant reduced thermal degradation rate of epoxy resins in the primary stage, and promote the formation of carbon layer.


2015 ◽  
Vol 39 (3) ◽  
pp. 2269-2278 ◽  
Author(s):  
Omid Zabihi ◽  
Hamid Khayyam ◽  
Bronwyn L. Fox ◽  
Minoo Naebe

Relationship between thermal degradation model of epoxy nanocomposites containing different types of modified nanoclay and their structural changes is explained.


2015 ◽  
Vol 50 (10) ◽  
pp. 3697-3705 ◽  
Author(s):  
Vinicios Pistor ◽  
Lucas Puziski ◽  
Ademir J. Zattera

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