scholarly journals Investigation of physical and chemical properties, performance and behavior in fire conditions of epoxy compositions modified with inhibitory fillers

2021 ◽  
Vol 2131 (4) ◽  
pp. 042044
Author(s):  
D Totskiy ◽  
V Borisova ◽  
A Davidenko ◽  
E Kadochnikova ◽  
N Loran

Abstract The presented article presents the results of investigations of operational characteristics and thermal stability of polymer composites whose matrix is represented by epoxy resins modified with different kinds of inhibiting fillers. An analytical literature review has been performed, methods and methods of obtaining flame retardant composites have been studied. Experimental study of the influence of inhibiting modifiers - fine fillers: iron oxide, silica flour, graphite, talcum, copper oxide has been carried out. According to the results of the experimental study, the modification of the epoxy matrix of the composite by the introduction of inhibiting fillers by ultrasonic treatment contributes to an increase in thermal stability. The modified material is characterized by decrease of intensity of destruction of the material matrix, expressed in decrease of mass loss level, decrease of maximum value of thermal effect, increase of oxidation period, and also steady formation of a thermal insulating carbonaceous layer.

1981 ◽  
Vol 36 (11) ◽  
pp. 1444-1450 ◽  
Author(s):  
Max Schmidt ◽  
Erich Sametschek

Abstract The first examples of the hitherto unknown 1,2,4-Trithia-3,5-diborolanes with B-O-C-bonds have been synthesized and characterised. The diiodo substituted ring (2) reacts with 2,6-dimethylphenol, to form 3,5-bis-(2,6-dimethylphenyloxi)-1,2,4-trithia-3,5-di-borolane (3) and HI. 3,5-Diethoxi-1,2,4-trithia-3,5-diborolane, 5, and C2H5I are formed via the cleavage of diethylether by 2. From 2 and diisopropylether, the corresponding 3,5-diisopropyloxi-1,2,4-trithia-3,5-diborolane (6) is formed. The unsymmetrical ethers methyl-t-butylether and methylphenylether undergo reactions with 2 resulting in the formation of 3,5-dimethyloxi-1,2,4-trithia-3,5-diborolane (8) (besides t-C4H9I) and 3,5-diphenyloxi-1,2,4-trithia-3,5-diborolane (10) (besides CH3I). The thermal stability of the new compounds is increasing with increasing size of R in the -OR group and from aliphatic to aromatic R in this group. IR, Raman, 1H NMR and 11B NMR spectra of the compounds are reported as well as some physical and chemical properties.


2017 ◽  
Vol 19 (9) ◽  
pp. 6497-6507 ◽  
Author(s):  
David M. Bell ◽  
Dan Imre ◽  
Scot T. Martin ◽  
Alla Zelenyuk

Chemical transformations and aging of secondary organic aerosol (SOA) particles can alter their physical and chemical properties, including particle morphology.


RSC Advances ◽  
2017 ◽  
Vol 7 (59) ◽  
pp. 37441-37446 ◽  
Author(s):  
Qingzhi Wang ◽  
Jiankun Liu ◽  
Lingqing Wang

Freeze–thaw cycles (FTCs) can strongly influence the physical and chemical properties of soils in cold regions, which can in turn affect the adsorption–desorption characteristics of phosphorus (P) in the soil.


2014 ◽  
Author(s):  
Hidemasa Iwata ◽  
Athanasios Konstandopoulos ◽  
Kazuki Nakamura ◽  
Kazutake Ogyu ◽  
Kazushige Ohno

2015 ◽  
Vol 69 (1) ◽  
Author(s):  
Jaroslav Filip ◽  
Peter Kasák ◽  
Jan Tkac

AbstractEarly diagnosis of diseases with minimal cost and time-consumption has become achievable due to recent advances in the development of biosensors. These devices use biorecognition elements for the selective interaction with an analyte and the signal read-out is obtained via different types of transducers. The operational characteristics of biosensors have been reported as improving substantially when a diverse range of nanomaterials is employed. This review presents the construction of electrochemical biosensors based on graphene, atomically thin 2D carbon crystals, a nanomaterial currently the subject of intensive studies. Here, the most attractive directions for graphene applications in biosensor preparation are discussed, including novel detection and amplification schemes exploiting graphene’s unique electrochemical, physical and chemical properties. There is probably a very bright future for graphene-based biosensors, but much further work is required to fulfill the high expectations.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jia-Bao Liu ◽  
Hani Shaker ◽  
Imran Nadeem ◽  
Muhammad Hussain

The degree-based topological indices are used to correlate the physical and chemical properties of a molecule with its chemical structure. Boron nanotubular structures are high-interest materials due to the presence of multicenter bonds and have novel electronic properties. These materials have some important issues in nanodevice applications like mechanical and thermal stability. Therefore, they require theoretical studies on the other properties. In this paper, we present certain degree-based topological indices such as ABC, the fourth ABC, GA, and the fifth GA indices for boron triangular and boron-α nanotubes.


Background: The technological developments for nanocellulose production from cheaper plant materials compared to wood, in particular, agricultural waste is an urgent task of nanobiophysics. The discovery of possibility of expanding the functional characteristics of materials in compositions with modified cellulose particles essentially stimulated the interest of researchers in cellulose composites. Surface modification of cellulose particles by functional materials, such as dyes, metal oxides, silicon, allows applying composites with modified cellulose in various areas of modern industry. A significant improvement in the operational performances of functionalized cellulose particles can be achieved by using them as filler in polymers. Epoxy resin compositions with modified and unmodified cellulose particles, studied in present work, are an example of hybrid biosystem. The interfacial interaction of filler particles with the epoxy matrix, their concentration and dispersion can change the physical and chemical properties of the biopolymer and the functional parameters of biocomposites. Studying the influence of external fields on the physical and chemical properties of epoxy resin-based biosystems and their influence on operational parameters seems to be an urgent problem of advanced and sustained materials science. Objectives: The purpose of this work was to develop an effective nanocellulose synthesis from plant materials and surface functionalization of micro- and nanocellulose particles with clathrochelate iron (ΙΙ) dye as well obtaining biocompositions of epoxy resin with functionalized and non-functionalized micro- and nanocellulose, and to explore of the morphology, chemical resistance, mechanical and thermal properties of epoxy composites with cellulose micro and nanoparticles. Materials and methods: The studying objects were the composites of epoxy resin Eposir-7120 with a polyethylene polyamine “PEPA” hardener in a ratio of 6.2:1 and 10% cellulose micro and nanoparticles. The microcellulose obtained from wood has been a commercial product. Nanocellulose has been synthesized from organosolv cellulose obtained from Miscanthus x giganteus stalks. Surface modification of micro- and nanocellulose was performed using the clathrochelate iron (ΙΙ) dye. The specific surface area of cellulose particles was determined using low-temperature nitrogen adsorption-desorption according to the Brunauer-Emmett-Teller method. Mechanical parameters were determined using universal Shopper and UMM-10 machines. Thermal analysis was performed using Q1500 analyzer. Swelling was determined by the gravimetric method. Results: Elastic modulus E, compressive strength σ and thermogravimetric parameters were determined. It was shown that in composites with micro and nanocellulose the E rises in 7.0–12.2% while the σ increases in 9.1% for composites with cellulose micro particles. The loading resin with nanocellulose and modified cellulose microparticles no affects the σ value of composites. The thermal stability of epoxy polymer (310°C) reduces after loading with micro and nanocellulose to 290 and 300°C, respectively. Chemical resistance of composites with both celluloses to 20% nitric acid reduces. In neutral medium swelling characterizes by rapid sorption to saturation of 15–20% acetone in 36 hours. Conclusions: Thus, the synthesis method of nanocellulose from plant materials and functionalization of its surface with clathrochelate iron (ΙΙ) were developed. Light response of dye was detected in visible spectral range. Epoxy resin composites with 10% micro and nanocellulose were obtained. The filling effect with micro- and nanocellulose at elastic modulus, compressive strength, and thermal stability of epoxycomposites was studied. The swelling processes run similarly in composites with cellulose micro and nanoparticles.


Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 11
Author(s):  
Dmitry Alexandrovich Korolchenko ◽  
Tatiana Yurievna Eremina

Mathematical and experimental research plays an active role in fire protection investigation. The choice of optimal conditions for the experimental program is the main methodological part of this research. The peculiarities of new fire-protective compositions were investigated. Many experiments in this work are aimed at the investigation of the physical and chemical properties of the materials.


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