scholarly journals Controlling mass loss from RTM6 epoxy resin under simulated vacuum infusion conditions

2022 ◽  
pp. 107473
Author(s):  
Andrew J. Parsons ◽  
Aleksandra Gonciaruk ◽  
Xuesen Zeng ◽  
Fernando Sarce Thomann ◽  
Peter Schubel ◽  
...  
2018 ◽  
Vol 251 ◽  
pp. 01034 ◽  
Author(s):  
Elena Pokrovskaya

The Anglican Church in Arkhangelsk built in 1833 represents a wooden architecture monument. The article describes the strengthening of partially destroyed samples of the Anglican Church wood by surface modification. The first layer of the sandwich coating is nitrilotrimethylphosphonic acid, which forms covalent bonds with the substrate, partially strengthening the wood. The second layer is an epoxy resin solution, which forms covalent bonds with the coating of the first layer, with hydroxyl groups of the first layer involved in the curing of the second layer as well. A two-layer surface coating is formed, while the strength of the wood increases by 2 – 2.5 times, water absorption decreases by 3 times, and mass loss in combustion is no more than 9% according to GOST 27484-87. The monument preservation increases.


2010 ◽  
Vol 165 (11) ◽  
pp. 857-867 ◽  
Author(s):  
Yu Gao ◽  
Sheng-Ling Jiang ◽  
Shang-Li Dong ◽  
De-Zhuang Yang

Author(s):  
Yu Gao ◽  
Mingren Sun ◽  
Dezhuang Yang ◽  
Shiyu He ◽  
Jinhe Wang ◽  
...  
Keyword(s):  

2015 ◽  
Vol 1129 ◽  
pp. 123-130 ◽  
Author(s):  
Tomasz Piotrowski ◽  
Piotr Gawroński

One of the main advantage of Concrete-Polymer Composites (C-PC) in relation to Cement Concrete called Ordinary Concrete is its chemical resistance. There is no European standard for testing the chemical resistance of cement based concretes and C-PC. American standards ASTM provide varied concrete tests depending on exposure conditions and mechanisms of destruction of concrete structures but there is a lack of clear criteria for the evaluation of research results by these methods. There are also requirements for monolithic floors chemical resistance - ASTM C722-04 and the requirements of the standard EN 1504-2, but they involve coating materials and cannot be directly applied to the cement concrete and C-PC. The paper presents the experimental studies of chemical resistance of C-PC in relation to OC. The investigations has been made under different environment conditions. First the samples of Ordinary Concrete (OC), Polymer Concrete (PC-1) based on vinylester resin and Polymer-Cement Concrete (PCC-1) with polyacrylic dispersion used as a co-binder were immersed for a period of time up to 168 days in a distilled water, H2SO4, MgSO4, (NH4)2SO4 and mix of the mentioned. During the storage the pH was controlled. Additionally as a reference the samples were conditioned in a climate chamber (20°C, 60% RH). The compressive strength were tested after defined periods of time. Next experiment was performed on OC and three different PCC – first modified with synthetic latex, second with polyacrylic polymer dispersion and the last with epoxy resin. The samples were immersed in H2SO4 up to 90 days. Compressive strength and mass loss after 30 and 90 days of conditioning were measured. As a reference the water immersion was used. The results obtained in this experimental program showed high chemical resistance of Polymer Concrete. PC samples obtained continuous increases of compressive strength in all examined chemically aggressive environments. It is also confirmed higher chemical resistance of Polymer-Cement Concrete modified with vinylester resin in relation to Ordinary Concrete. The second part of the program showed that the best additive to PCC among poliacrylic dispersion, synthetic latex and epoxy resin was last one. Epoxy modified PCC samples obtained best results both in compressive strength and mass loss tests


2019 ◽  
Vol 202 ◽  
pp. 44-50 ◽  
Author(s):  
Radim Skoupy ◽  
Jana Nebesarova ◽  
Miroslav Slouf ◽  
Vladislav Krzyzanek
Keyword(s):  

2017 ◽  
Vol 100 ◽  
pp. 269-274 ◽  
Author(s):  
Liang Yue ◽  
Anthony Maiorana ◽  
Ammar Patel ◽  
Richard Gross ◽  
Ica Manas-Zloczower
Keyword(s):  

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Weisong Sun ◽  
Sirong Yu ◽  
Menglong Tang ◽  
Xian Wang

The graphene was modified by silane coupling agent KH560, the epoxy resin was reinforced by the modified graphene (KH-graphene) to produce KH-graphene/epoxy resin composites, and the effect of KH-graphene content and load on the friction and wear property of the composites was studied. The results showed that the KH560 was successfully grafted to the surface of graphene; The KH-graphene decreased the mass loss and friction coefficient of the epoxy resin, and with increasing the KHgraphene content, the mass loss and friction coefficient of KH-graphene/epoxy resin composites both showed a decreasing trend, and when the load was 150N, KH-graphene content was 0.5%, the mass loss and friction coefficient of composites were reduced by 44.9% and 17.4%; With increasing the load, the mass loss and friction coefficient of KH-graphene/epoxy resin composites also showed a decreasing trend; The wear form was mainly fatigue wear under the low load, and KH-graphene could inhibit the generation and expansion of micro-cracks; After the load increased, the wear form was mainly abrasive wear; After the graphene added, the wear scar of the worn surface of composites was relatively reduced.


Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.


Author(s):  
J. Temple Black ◽  
William G. Boldosser

Ultramicrotomy produces plastic deformation in the surfaces of microtomed TEM specimens which can not generally be observed unless special preparations are made. In this study, a typical biological composite of tissue (infundibular thoracic attachment) infiltrated in the normal manner with an embedding epoxy resin (Epon 812 in a 60/40 mixture) was microtomed with glass and diamond knives, both with 45 degree body angle. Sectioning was done in Portor Blum Mt-2 and Mt-1 microtomes. Sections were collected on formvar coated grids so that both the top side and the bottom side of the sections could be examined. Sections were then placed in a vacuum evaporator and self-shadowed with carbon. Some were chromium shadowed at a 30 degree angle. The sections were then examined in a Phillips 300 TEM at 60kv.Carbon coating (C) or carbon coating with chrom shadowing (C-Ch) makes in effect, single stage replicas of the surfaces of the sections and thus allows the damage in the surfaces to be observable in the TEM. Figure 1 (see key to figures) shows the bottom side of a diamond knife section, carbon self-shadowed and chrom shadowed perpendicular to the cutting direction. Very fine knife marks and surface damage can be observed.


Author(s):  
J. G. Adams ◽  
M. M. Campbell ◽  
H. Thomas ◽  
J. J. Ghldonl

Since the introduction of epoxy resins as embedding material for electron microscopy, the list of new formulations and variations of widely accepted mixtures has grown rapidly. Described here is a resin system utilizing Maraglas 655, Dow D.E.R. 732, DDSA, and BDMA, which is a variation of the mixtures of Lockwood and Erlandson. In the development of the mixture, the Maraglas and the Dow resins were tested in 3 different volumetric proportions, 6:4, 7:3, and 8:2. Cutting qualities and characteristics of stability in the electron beam and image contrast were evaluated for these epoxy mixtures with anhydride (DDSA) to epoxy ratios of 0.4, 0.55, and 0.7. Each mixture was polymerized overnight at 60°C with 2% and 3% BDMA.Although the differences among the test resins were slight in terms of cutting ease, general tissue preservation, and stability in the beam, the 7:3 Maraglas to D.E.R. 732 ratio at an anhydride to epoxy ratio of 0.55 polymerized with 3% BDMA proved to be most consistent. The resulting plastic is relatively hard and somewhat brittle which necessitates trimming and facing the block slowly and cautiously to avoid chipping. Sections up to about 2 microns in thickness can be cut and stained with any of several light microscope stains and excellent quality light photomicrographs can be taken of such sections (Fig. 1).


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