Graphene-based masterbatch obtained via modified polyvinyl alcohol liquid-shear exfoliation and its application in enhanced polymer composites

2017 ◽  
Vol 134 ◽  
pp. 103-110 ◽  
Author(s):  
Douglas A. Simon ◽  
Eveline Bischoff ◽  
Giovanna G. Buonocore ◽  
Pierfrancesco Cerruti ◽  
Maria G. Raucci ◽  
...  
2013 ◽  
Vol 592-593 ◽  
pp. 647-650 ◽  
Author(s):  
Małgorzata Lenart

Cement – polymer composites are nowadays widely used in repair systems not only in case of concrete or reinforced concrete constructions but also in masonry. Polymers addition for example already at 5% m.c. modifies the structure of the cement – polymer composite in a way that many of the mechanical properties such as flexural strength, tensile strength or adhesion to substrates are improved. The paper presents the results of tests such as flexural, compressive or adhesion strength to ceramic substrate of hardened cement mortars with different composition, as well as selected cement mortars modified by two polymers: polyvinyl alcohol and styrene – butadiene polymer dosed at 5 % m.c. Four types of cement mortars modified by lime (component used in historical constructions as well as in contemporary masonry mortars) are also examined for comparison.


1999 ◽  
Vol 576 ◽  
Author(s):  
J. C. Grujnlan ◽  
W. W. Gerberich ◽  
L. F. Francis

ABSTRACTIn an effort to lower the percolation threshold of carbon black-filled polymer composites, various polymer microstructures were examined. Composites prepared with a polyvinyl acetate (PVAc) latex and a poly(vinyl acetate – ethylene) water-dispersible powder showed a significantly lowered percolation threshold relative to an equivalently prepared composite that used a polyvinyl alcohol (PVA) solution to form the matrix phase. The percolation threshold of the dispersion-based composites occurred at 5 vol.% carbon black, while the equivalent solutionbased composite produced a threshold at 14 vol.%. By excluding the carbon black from regions occupied by polymeric particles, the dispersion-based composites lead to preferential aggregation of carbon black, as evidenced by SEM, and a lowered percolation threshold.


Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 76 ◽  
Author(s):  
Qinghua Wei ◽  
Yanen Wang ◽  
Yiwen Rao ◽  
Anguo Jiang ◽  
Kun Zhang ◽  
...  

Due to the superior performances of nanosilica particles, this research has been designed to study their effects on the mechanical and trigological properties of a PVA/PAM polymer composite by a molecular dynamics simulation method. To realize the research objectives mentioned above, the molecular models of amorphous cells and sandwiched friction models for pure polyvinyl alcohol (PVA)/polyacrylamide (PAM) (component weight ratio is 1:1) and PVA/PAM/nanosilica (component weight ratio is 5.75:5.75:1) polymer composites were constructed and simulated, respectively. The simulation results of the mechanical properties show increases about 31.6% in the bulk modulus, 53.1% in the shear modulus, and 50.1% in the Young’s modulus by incorporating a nanosilica particle into a pure PVA/PAM polymer composite. Meanwhile, the changes in Cauchy pressure, B/G ratio, and Poisson’s ratio values indicate that incorporating a nanosilica particle into pure PVA/PAM weakened the ductility of the composite. Incorporating a nanosilica particle into a pure PVA/PAM composite also showed a decrease about 28.2% in the abrasion rates and relative concentration distributions of polymer molecules in the final friction models. Additionally, the binding energy and the pair correlation functions between a nanosilica particle and the polymer chains in a cubic cell demonstrate that incorporating nanosilica into PVA/PAM polymer composites improves the internal binding strength between different components through the forming hydrogen bonds. As a result, the mechanical and tribological properties of PVA/PAM polymer composites can be enhanced by incorporating nanosilica particles.


2022 ◽  
Vol 92 (1) ◽  
pp. 131
Author(s):  
В.Г. Костишин ◽  
И.М. Исаев ◽  
Р.И. Шакирзянов ◽  
Д.В. Салогуб ◽  
А.Р. Каюмова ◽  
...  

The electromagnetic and radio-absorbing characteristics of ferrite-polymer composites with conductive inclusions based on polyvinyl alcohol are investigated. The Ni-Zn spinel ferrite powder of 2000NN grade with composition Ni0.32Zn0.68Fe2O4 was used as filler. It is shown that the obtained composites are effective absorbers in the frequency range of 2⸺5 GHz with peak reflection loss less than –20 dB. Through the analysis of the permittivity spectra and permeability spectra, as well as the calculated reflection loss spectra, critical factors of the electromagnetic wave absorption in obtained composites are established.


2016 ◽  
Vol 18 (3) ◽  
pp. 175-182
Author(s):  
Dana A. Tahir ◽  
◽  
Soran M. Mamand ◽  
Sarkawt A. Hussein ◽  
◽  
...  

2011 ◽  
Vol 290 (4) ◽  
pp. 359-370 ◽  
Author(s):  
Andrea Dorigato ◽  
Alessandro Pegoretti

RSC Advances ◽  
2016 ◽  
Vol 6 (86) ◽  
pp. 83356-83365 ◽  
Author(s):  
Xiaran Miao ◽  
Feng Tian ◽  
Jinyou Lin ◽  
Hui Li ◽  
Xiuhong Li ◽  
...  

Cellulose nanofibrils (CNF) with polymorphs of cellulose I and II are different in morphology, aspect ratio, density of functional groups and mechanical properties, which influence the reinforcement effect for polymer composites.


2017 ◽  
Vol 70 ◽  
pp. 41-49 ◽  
Author(s):  
K. Naveen Kumar ◽  
L. Vijayalakshmi ◽  
Jong Su Kim ◽  
Jaesool Shim ◽  
Migyung Cho ◽  
...  

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