scholarly journals A Review on Epoxy and Polyester Based Polymer Concrete and Exploration of Polyfurfuryl Alcohol as Polymer Concrete

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Rakesh Kumar

Petroleum based epoxy and polyester based thermoset resins can be used to produce high-quality polymer concrete. However, petroleum based resources are finite and this has necessitated the development of thermoset bioresins to be used as polymer concrete. Furfuryl alcohol (FA), a thermoset bioresin, is derived from lignocellulosic biomass and it can be polymerized into polyfurfuryl alcohol (PFA) in the presence of an acid catalyst. The highly exothermic polymerization reactions involving conversion of FA to PFA can be used to fabricate PFA based concrete with rock-like structure. The PFA based polymer concrete offers the broadest range of chemical resistance against acid and alkali over all other types of polymer concrete which are based upon different thermoset polymeric systems. In this review paper, we have discussed the formulations (incorporation of aggregates, fillers, and resin) and properties (especially compressive and flexural) of epoxy and polyester based polymer concrete. In another section, we have given the mechanical, thermal, and water resistance properties of PFA based biopolymer, biocomposites, nanocomposites, and polymer concrete. Lastly, we have tried to explore whether PFA can be used successfully as biopolymer concrete or not.

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4412
Author(s):  
Emanuele Cesprini ◽  
Primož Šket ◽  
Valerio Causin ◽  
Michela Zanetti ◽  
Gianluca Tondi

One of the major challenges currently in the field of material science is finding natural alternatives to the high-performing plastics developed in the last century. Consumers trust synthetic products for their excellent properties, but they are becoming aware of their impact on the planet. One of the most attractive precursors for natural polymers is tannin extracts and in particular condensed tannins. Quebracho (Schinopsis balansae) extract is one of the few industrially available flavonoids and can be exploited as a building block for thermoset resins due to its phenol-like reactivity. The aim of this study was to systematically investigate different hardeners and evaluate the water resistance, thermal behavior, and chemical structure of the quebracho tannin-based polymers in order to understand their suitability as adhesives. It was observed that around 80% of the extract is resistant to leaching when 5% of formaldehyde or hexamine or 10% of glyoxal or furfural are added. Additionally, furfuryl alcohol guarantees high leaching resistance, but only at higher proportions (20%). The quebracho-based formulations showed specific thermal behavior during hardening and higher degradation resistance than the extract. Finally, these polymers undergo similar chemistry to those of mimosa, with exclusive reactivity of the A-ring of the flavonoid.


2020 ◽  
Vol 5 (11) ◽  
Author(s):  
Lindsey A Welch

AbstractGreen chemistry and sustainability are important concepts to incorporate into the undergraduate chemistry curriculum. Through the development of innovative undergraduate chemistry research projects in these areas, retention of students in the physical sciences can be improved. This paper describes two projects in undergraduate catalysis research: hydrogenation of furfural and the esterification of biooil from pyrolyzed wood. Catalytic transfer hydrogenation (CTH) of furfural with Pd/C led to the production of furfuryl alcohol, furfuryl isopropyl ether, 2-methylfuran, and tetrahydrofurfuryl alcohol. The metal chloride additives improved selectivity for furfuryl alcohol and furfuryl isopropyl ether. Catalytic conversion of pyrolyzed wood biooil in ethanol with a solid acid catalyst yielded ethyl esters, including ethyl acetate and ethyl propionate, as characterized by GC/MS These projects are described in the context of engaging undergraduate students in hands-on research for the purpose of improving retention and persistence, as well as preparing young scientists to enter graduate programs and the STEM workforce.


2021 ◽  
Vol 23 (1) ◽  
pp. 7-27
Author(s):  
Peter Kjær Willendrup ◽  
Kim Lefmann

A key element of the success of McStas is the component layer where users and developers alike are contributing to the description of new physical models and features. In McStas, components realise all physical elements of the simulated instrument from source via optics and samples to detector. In this second review paper of the McStas package, we present an overview of the component classes in McStas: sources, monitors, optics, samples, misc, and contrib. Within each component class we give thorough examples of high-quality components, including their algorithms and example use. We present two example instruments, one for a continuous source and one for a time-of-flight source, that together demonstrate the use of the main component classes. Finally, we give tips and instructions that will allow the reader to write good components and elucidate the pathway of contributing new components to McStas.


2020 ◽  
Vol 44 (39) ◽  
pp. 16810-16820
Author(s):  
Rosanna Viscardi ◽  
Vincenzo Barbarossa ◽  
Daniele Mirabile Gattia ◽  
Raimondo Maggi ◽  
Giovanni Maestri ◽  
...  

Superiorty of the supported sulfonic acid catalyst in terms of the water resistance and efficiency of the acid sites compared to the commercial reference.


2016 ◽  
Vol 1 (19) ◽  
pp. 6079-6085 ◽  
Author(s):  
Md. Mominul Islam ◽  
Subhajit Bhunia ◽  
Rostam Ali Molla ◽  
Asim Bhaumik ◽  
Sk. Manirul Islam

Author(s):  
Vladimir N. Koshelev ◽  
Boris P. Tonkonogov ◽  
Anastasia Yu. Kilyakova ◽  
Karine G. Aleksanyan ◽  
Eldar M. Movsumzade ◽  
...  

In connection with development of techniques and technologies and unification and substitution the most important task for Russia is to solve the problem of development and introduction of modern high-quality domestic greases. The most suitable in this respect is greases with the urea derivatives thickener — organic compounds containing in molecules one or more urea (urea, wreath) groups. In recent years, the production of these lubricants attracts increased attention of specialists, because they have unique exploitation characteristics: the combination of high-hydrolytic and chemical resistance, operability in a wide temperature range, thermo-strengthening lack, retention its properties at high speeds and specific loads, in contact with adverse environments, etc.  We received greases based on poly urea with the addition of pigment. The synthesized pigments have different structure and belong to different classes of compounds. We conducted a search for the most optimal structures and concentrations of pigments which are included in the poly urea grease.


2021 ◽  
Vol 10 (1) ◽  
pp. 53
Author(s):  
Franziska Verena Oberhaus ◽  
Dieter Frense

Due to their unique properties, polythiophene and other conductive polymers have become the subject of intensive research and are promising substrate materials for innovative and trendsetting applications. To this day, boron trifluoride diethyl etherate (BFEE) is the preferred solvent for the electropolymerization of thiophene, although it does not allow for reproducible film qualities due to its decomposition under ambient conditions. We therefore want to equip the reader with a starter kit for the electropolymerization of high-quality polythiophene films from stable solvents and a simple yet efficient method to remove the deposited films from the electrodes for their reuse. By drying the working solution prior to its utilization, and by adding a Lewis acid catalyst, films that display enhanced electron transfer and a smooth surface topography can be obtained, which can both be beneficial for the analytic performance of a subsequently built biosensor.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Luciano Leonardi ◽  
Teresa M. Pique ◽  
Tomas Leizerow ◽  
Humberto Balzamo ◽  
Celina Bernal ◽  
...  

Polymer concrete is a composite using polymer instead of portland cement as a binder. It allows optimizing the tensile and cracking strength and the chemical resistance of a concrete structure. In this study, different formulations were assessed in order to optimize a polymer concrete underground utility manhole with minimum weight. Formulations were based on an epoxy-amine system mixed with fine regular-weight aggregates and ultralightweight aggregates. The objective was to design and assess an underground utility structure with the epoxy chemical resistance, strength, and lightweight and to study whether the replacement of regular-weight aggregates by ultralightweight aggregates would contribute to improve the strength and reduce the structure weight. Two polymer concrete systems were designed from its formulation, and their mechanical performance was evaluated experimentally. A numerical model was developed for a polymer concrete underground utility structure made from the different formulations. It was simplified as a box subjected to typical soil loads. The size of the box is a standard one. Its minimum wall thickness is specified for sustaining the in-use service pressures obtained from numerical simulation. The model predicted that the epoxy/regular-weight aggregate formulation could be used with a wall thickness significantly smaller than the formulation with ultralightweight aggregates. In addition, the underground utility structure made with this formulation would weigh six times less than the same box made with a traditional portland cement concrete.


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