Effect of the ladder-like aminopropyl silsesquioxane on the curing and properties of epoxy composition

2020 ◽  
Vol 923 ◽  
pp. 121395
Author(s):  
Yulia V. Olikhova ◽  
Vladimir S. Osipchik ◽  
Natalia V. Kostromina ◽  
Oleg I. Loban
Keyword(s):  
2019 ◽  
pp. 146-156
Author(s):  
F. A. Nasonov ◽  
V. M. Aleksashin ◽  
D. A. Melnikov ◽  
S. V. Bukharov

The influence of the special modification of epoxy resins and polymer composites based on them on the basic technological properties of the composition is investigated. Modification is performed in order to reduce the opening damage. The most important technological properties of the initial epoxy composition and modified technological additives are studied and compared by standard methods (viscosimetry, thermoanalytical methods). A kinetic model of the curing process was created, the experimental production of samples from plastics filled with carbon long filler (impregnation under pressure, autoclave molding) and its non-destructive testing were carried out.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 411
Author(s):  
Izabela Miturska ◽  
Anna Rudawska ◽  
Miroslav Müller ◽  
Monika Hromasová

The proper process of preparing an adhesive composition has a significant impact on the degree of dispersion of the composition ingredients in the matrix, as well as on the degree of aeration of the resulting composition, which in turn directly affects the strength and functional properties of the obtained adhesive compositions. The paper presents the results of tensile strength tests and SEM microphotographs of the adhesive composition of Epidian 57 epoxy resin with Z-1 curing agent, which was modified using three fillers NanoBent ZR2 montmorillonite, CaCO3 calcium carbonate and CWZ-22 active carbon. For comparison purposes, samples made of unmodified composition were also tested. The compositions were prepared with the use of six mixing methods, with variable parameters such as type of mixer arm, deaeration and epoxy resin temperature. Then, three mixing speeds were applied: 460, 1170 and 2500 rpm. The analyses of the obtained results showed that the most effective tensile results were obtained in the case of mixing with the use of a dispersing disc mixer with preliminary heating of the epoxy resin to 50 °C and deaeration of the composition during mixing. The highest tensile strength of adhesive compositions was obtained at the highest mixing speed; however, the best repeatability of the results was observed at 1170 rpm mixing speed. Based on a comparison test of average values, it was observed that, in case of modified compositions, the values of average tensile strength obtained at mixing speeds at 1170 and 2500 rpm do not differ significantly with the assumed level of significance α = 0.05.


Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 265
Author(s):  
Natalia Sienkiewicz ◽  
Midhun Dominic ◽  
Jyotishkumar Parameswaranpillai

Epoxy resins as important organic matrices, thanks to their chemical structure and the possibility of modification, have unique properties, which contribute to the fact that these materials have been used in many composite industries for many years. Epoxy resins are repeatedly used in exacting applications due to their exquisite mechanical properties, thermal stability, scratch resistance, and chemical resistance. Moreover, epoxy materials also have really strong resistance to solvents, chemical attacks, and climatic aging. The presented features confirm the fact that there is a constant interest of scientists in the modification of resins and understanding its mechanisms, as well as in the development of these materials to obtain systems with the required properties. Most of the recent studies in the literature are focused on green fillers such as post-agricultural waste powder (cashew nuts powder, coconut shell powder, rice husks, date seed), grass fiber (bamboo fibers), bast/leaf fiber (hemp fibers, banana bark fibers, pineapple leaf), and other natural fibers (waste tea fibers, palm ash) as reinforcement for epoxy resins rather than traditional non-biodegradable fillers due to their sustainability, low cost, wide availability, and the use of waste, which is environmentally friendly. Furthermore, the advantages of natural fillers over traditional fillers are acceptable specific strength and modulus, lightweight, and good biodegradability, which is very desirable nowadays. Therefore, the development and progress of “green products” based on epoxy resin and natural fillers as reinforcements have been increasing. Many uses of natural plant-derived fillers include many plant wastes, such as banana bark, coconut shell, and waste peanut shell, can be found in the literature. Partially biodegradable polymers obtained by using natural fillers and epoxy polymers can successfully reduce the undesirable epoxy and synthetic fiber waste. Additionally, partially biopolymers based on epoxy resins, which will be presented in the paper, are more useful than commercial polymers due to the low cost and improved good thermomechanical properties.


1973 ◽  
Vol 7 (2) ◽  
pp. 256-261
Author(s):  
L. A. Faitel'son ◽  
V. D. Kiseleva ◽  
V. I. Alksne

2013 ◽  
Vol 486 ◽  
pp. 181-188 ◽  
Author(s):  
Pavol Novák ◽  
Milan Žmindák ◽  
Zoran Pelagić

The aim of this paper is first to determine the state of stress of welded joint repaired by steel sleeve and epoxy composition. Experimental measurements are performed on samples to determine required material properties. The structural analysis by finite element method (FEM) is performed for a pressurized pipe with insufficiently welded root and installed cold sleeve. Simulated is the case of depressurized pipes that could cause a breach of cohesion between filling material and surface of pipe or sleeve with usage of cohesive finite elements. In the end the sleeve dimensions are optimized with respect to maximum integrity to the repaired sleeve.


1993 ◽  
Vol 20 (1-2) ◽  
pp. 15-18
Author(s):  
S. G. Bychkov ◽  
N. A. Bogatyreva ◽  
A. M. Timoshkin

2021 ◽  
pp. 132-140
Author(s):  
S.L. Barbotko ◽  
◽  
M.M. Bochenkov ◽  
O.S. Volnyj ◽  
O.P. Korobeinichev ◽  
...  

Studies have been carried out to assess the effectiveness of fire retardants on the flammability of an epoxy composition – graphene and an organophosphorus compound DOPO-THPO. The concentrations of the added flame retardants were 2 and 4 % (mass). Flammability characteristics were determined using the method according to GOST 28157 (UL 94) with vertical and horizontal samples. It was found that the introduction of fire retardants reduces the flammability of the epoxy composition, but the introduction of even 4 % was insufficient to ensure self-extinguishing of the epoxy composition during vertical testing.


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