STUDY OF THE PLASTICIZING EFFECT OF MOISTURE ON THE PROPERTIES OF VSE-34 BINDER BASED PCMS AFTER 5 YEARS EXPOSURE IN THE DIFFERENT CLIMATE ZONES

2021 ◽  
pp. 105-116
Author(s):  
T.V. Koval ◽  
◽  
I.M. Veligodsky ◽  
A.A. Gromova ◽  
◽  
...  

The plasticizing effect of moisture on the glass transition temperature of VSE-34 solvent-free epoxy binder based polymer composite materials (PCMs) with different reinforcement was studied. Natural weathering was performed in three climatic regions of Russia: Moscow, Gelendzhik, Sochi. It was shown that the glass transition temperature is significantly reduced after 1 year of exposure and then is gradually increased after 3 and 5 years of exposure. Samples were studied in «as-received» state as well as after drying and saturation by water till mass stabilization in order to investigate the moisture influence on PCMs’ glass transition temperature. Linear relationship between glass transition temperature and moisture content was observed.

2011 ◽  
Vol 83 (2) ◽  
pp. 934-939 ◽  
Author(s):  
Kiyoshi Kawai ◽  
Ken Fukami ◽  
Pariya Thanatuksorn ◽  
Chotika Viriyarattanasak ◽  
Kazuhito Kajiwara

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Krzysztof Lewandowski ◽  
Katarzyna Skórczewska ◽  
Kazimierz Piszczek ◽  
Włodzimierz Urbaniak

This paper presents the method of using glass fibre with carbon deposit (GFCD), derived from the recycling of wind turbine blades, for production of composite materials based on poly(vinyl chloride) (PVC). Composite materials containing from 1 to 15 wt% of GFCD were produced by plasticising with a plastographometer and then by pressing. The processability and performance were studied. Mechanical properties in static tension, impact strength, and thermal stability were determined. Glass transition temperature was also determined by means of the dynamic mechanical thermal analysis (DMTA). The GFCD percentage of up to 15 wt% was found not to slightly affect the change in the processability, thermal stability, and glass transition temperature. PVC/GFCD composite materials are characterised by a definitely greater elastic modulus with simultaneous decrease of tensile strength and impact strength. An analysis with scanning electron microscopy revealed good adhesion between the filler and the polymer matrix.


2012 ◽  
Vol 531 ◽  
pp. 153-156
Author(s):  
Ren Gui Peng ◽  
Cheng En He ◽  
Wei Tang ◽  
Yue E Liu ◽  
Ying Kui Yang

Poly(n-butyl acrylate) grafted silica nanoparticles were compounded with poly(methyl methacrylate) to yield silica/polymer composites with the improved dispersion of silica and interfacial adhesion with the matrix, thus showing increases in storage modulus and glass transition temperature.


2014 ◽  
Vol 10 (4) ◽  
pp. 583-594 ◽  
Author(s):  
Kong S. Ah-Hen ◽  
Roberto Lemus-Mondaca ◽  
Karen A. Mathias-Rettig ◽  
Antonio Vega-Gálvez ◽  
Jessica López

Abstract Adsorption and desorption isotherms of fresh and dried murtilla (Ugni molinae Turcz) berries were determined at 20, 40 and 60°C using a gravimetric technique. The experimental data obtained were fitted to eight models, namely GAB, BET, Henderson, Caurie, Smith, Oswin, Halsey and Iglesias–Chirife. A non-linear least square regression analysis was used to evaluate the models. The GAB model best fitted the experimental data. Isosteric heat of sorption was determined from the equilibrium sorption data using the Clausius–Clapeyron equation and was found to decrease exponentially with increasing moisture content. The enthalpy–entropy compensation theory applied to the sorption isotherms indicated an enthalpy controlled sorption process. Glass transition temperature of murtilla was determined by differential scanning calorimetry and modelled as a function of moisture content by the Gordon–Taylor equation and as function of water activity by Roos and Khalloufi models, which proved to be excellent tools for predicting glass transition of murtilla.


2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Heitor Luiz Ornaghi Junior 1 ◽  
Matheus Poletto 2 ◽  
Felipe Gustavo Ornaghi 3

Here, it is compiled data from literature for glass transition temperature (Tg) and activation energy (Ea) for different types of polymeric composite materials. A correlation among both parameters and dynamic mechanical curves is analyzed in terms of reinforcement effect and its correlation with the glassy and elastomeric moduli, as well the wideness of the main transition region. Besides, all results are discussed in terms of dynamic fragility. The results indicate that the glass transition temperature has not a direct relation with reinforcement effect promoted both in the glassy and/or elastomeric moduli. Moreover, the dynamic fragility concept seems do not be applied in polymeric composite materials since in the glass transition region the format of the storage, loss and tan delta curves vary strongly, depending on the specific polymeric composite material family.


BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 6933-6942
Author(s):  
Yuehua Zhu ◽  
Yaoli Zhang ◽  
Biao Pan

The viscoelasticity of Taxodium hybrid ‘Zhongshanshan’ wood, while undergoing hydrothermal processing, was investigated via dynamic thermomechanical analysis. The results showed that the elastic deformation and viscous deformation of the Taxodium hybrid ‘Zhongshanshan’ heartwood were greater than the sapwood. The heartwood average storage modulus and average loss modulus were greater than the sapwood. The difference between the heartwood and sapwood had little effect on the average glass transition temperature of their hemicellulose, which was approximately 74 °C. The radial average storage modulus was greater than the tangential, and the difference between the average loss modulus in the radial and tangential directions was negligible. The average glass transition temperature in the radial direction was slightly lower than the tangential direction. As the moisture content increased, the average storage modulus and its average hemicellulose glass transition temperature decreased. The average glass transition temperature tended to be lower as the moisture content increased. This study revealed the structural deformation and molecular movement of Taxodium hybrid ‘Zhongshanshan’ wood, while undergoing hydrothermal processing; this has important theoretical value for understanding its characteristics as well as its rational and efficient usage.


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