Thermo-Mechanical Performances of Polyethylene Fibres/Polyethylene Matrix Composites

Author(s):  
C. Marais
Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2395 ◽  
Author(s):  
Gianmarco Taveri ◽  
Enrico Bernardo ◽  
Ivo Dlouhy

Glass-based geopolymers, incorporating fly ash and borosilicate glass, were processed in conditions of high alkalinity (NaOH 10–13 M). Different formulations (fly ash and borosilicate in mixtures of 70–30 wt% and 30–70 wt%, respectively) and physical conditions (soaking time and relative humidity) were adopted. Flexural strength and fracture toughness were assessed for samples processed in optimized conditions by three-point bending and chevron notch testing, respectively. SEM was used to evaluate the fracture micromechanisms. Results showed that the geopolymerization efficiency is strongly influenced by the SiO2/Al2O3 ratio and the curing conditions, especially the air humidity. The mechanical performances of the geopolymer samples were compared with those of cellulose fiber–geopolymer matrix composites with different fiber contents (1 wt%, 2 wt%, and 3 wt%). The composites exhibited higher strength and fracture resilience, with the maximum effect observed for the fiber content of 2 wt%. A chemical modification of the cellulose fiber surface was also observed.


2005 ◽  
Vol 41 (11) ◽  
pp. 1172-1177 ◽  
Author(s):  
I. D. Kosobudsky ◽  
N. M. Ushakov ◽  
G. Yu. Yurkov ◽  
K. V. Zapsis ◽  
V. I. Kochubei ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3213
Author(s):  
Marc Marín-Genescà ◽  
Ramon Mujal Rosas ◽  
Jordi García Amorós ◽  
Lluis Massagues Vidal ◽  
Xavier Colom Fajula

Waste from pneumatic wheels is one of the major environmental problems, and the scientific community is looking for methods to recycle this type of waste. In this paper, ground tire rubber particles (GTR) from disused tires have been mixed with samples of low-density polyethylene (LDPE) and high-density polyethylene (HDPE), and morphological tests have been performed using scanning electron microscopy (SEM), as well as the dynamic electric analysis (DEA) dielectric characterization technique using impedance spectroscopy. From this experience, how GTR reinforcement influences polyethylene and what influence GTR particles have on the branched polyethylene has been detected. For pure LDPE samples, a Debye-type dielectric behavior is observed with an imperfect semicircle, which depends on the temperature, as it shows differences for the samples at 30 °C and 120 °C, unlike the HDPE samples, which do not show such a trend. The behavior in samples with Debye behavior is like an almost perfect dipole and is due to the crystalline behavior of polyethylene at high temperature and without any reinforcement. These have been obtained evidence that for branched PE (LPDE) the Maxwell Wagner Sillars (MWS) effect is highly remarkable and that this happens due to the intrachain polarization effect combined with MWS. This means that the permittivity and conductivity at LDPE/50%GTR are high than LDPE/70%GTR. However, it does not always occur that way with HDPE composites in which HDPE/70%GTR has the highest values of permittivity and conductivity, due to the presence of conductive fraction (Carbon Black-30%) in the GTR particles and their dielectric behavior.


2020 ◽  
Vol 168 ◽  
pp. 108537 ◽  
Author(s):  
Alyaa H. Abdalsalam ◽  
Erdem Şakar ◽  
Kawa M. Kaky ◽  
M.H.A. Mhareb ◽  
Betul Cevi̇z Şakar ◽  
...  

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