Characteristics of water absorption in amine-cured epoxy networks: a molecular simulation and experimental study

Soft Matter ◽  
2018 ◽  
Vol 14 (43) ◽  
pp. 8740-8749 ◽  
Author(s):  
Dujuan Zhang ◽  
Kai Li ◽  
Yan Li ◽  
Hao Sun ◽  
Jue Cheng ◽  
...  

By tuning the curing conversion of the DGEBA/DETDA cured epoxy resin, the structure factors that control water absorption can be studied.

RSC Advances ◽  
2016 ◽  
Vol 6 (1) ◽  
pp. 769-777 ◽  
Author(s):  
Kai Li ◽  
Ni Huo ◽  
Xinping Liu ◽  
Jue Cheng ◽  
Junying Zhang

Higher van der Waals interactions arising from the furan ring leads to improved thermomechanical properties of a cross-linked epoxy network.


RSC Advances ◽  
2013 ◽  
Vol 3 (20) ◽  
pp. 7452 ◽  
Author(s):  
Qing Yang ◽  
XiaoPing Yang ◽  
XiuDi Li ◽  
Lei Shi ◽  
Gang Sui

Author(s):  
Akarsh Verma ◽  
Kamal Joshi ◽  
Amit Gaur ◽  
V. K. Singh

In this article, bio-composites derived from starch-glycerol biodegradable matrix reinforced with jute fibers have been fabricated using the wet hand lay-up and compression moulding techniques. Samples having different weight percentages of jute fiber in the starch matrix have been analysed. The fibers surface was chemically treated by alkaline sodium hydroxide for improving the interphase bonding between fiber and matrix. Tensile test for the composites were done and the sample with highest tensile strength was selected for further tests that included water absorption, scanning electron microscopy and thermal analysis. It has been concluded that the ultimate tensile strength was found to be maximum for the composition of 15% fiber by weight composite as 7.547 MPa without epoxy coating and 10.43 MPa with epoxy coating. The major disadvantage of bio-composite is its high water absorption property, which in this study has been inhibited by the epoxy resin layer. Herein, the results of various tests done disclose a noteworthy improvement in the overall properties of bio-composite, in comparison to the neat biodegradable starch matrix.


2020 ◽  
Vol 14 (1) ◽  
pp. 247-261
Author(s):  
Zineb Kerrida ◽  
Hichem Berkak ◽  
Zoubir Makhloufi ◽  
Madani Bederina ◽  
Ahmida Ferhat

Introduction: In the Polymer Concrete (PC) composites, aggregates are the most important constituent, which considerably affect their performance. The purpose of this experimental study is to examine the effect of Gravel-to-Sand (G/S) ratio on the physico-mechanical, thermal and microstructural properties of epoxy micro-polymer concrete made up of local aggregates. Materials & Methods: The Micro Epoxy Polymer Concrete (MEPC) studied consists of epoxy resin as a binder and a mixture of two types of sands (alluvial (0/0.63 mm) and dune (0/4 mm) sands), as well as crushed limestone gravel (3/8 mm). Six compositions were prepared with two epoxy resin contents (10% and 14% of the total weight of mixture) and three G/S ratios (0.25, 0.50 and 0.75). The studied properties are density, water absorption, compressive and flexural strengths, thermal conductivity, thermal diffusivity, specific heat and macrostructure. Results & Discussion: The obtained results show that the G/S ratio, as well as the epoxy resin content, has a significant influence on the properties of MEPC. In addition, 14% epoxy resin and the G/S ratio of 0.75 can be considered as optimal values, which lead to very interesting physico-mechanical performances (denser and less porous material, more resistant with almost similar thermal conductivity). Moreover, the density, the water absorption and the optical microscopic observation confirm that mixes containing 14% epoxy are more impermeable, compact and homogeneous than those containing 10% epoxy. Conclusion: Finally, it should be noted that the incorporation of aggregates being relatively coarse decreases the grains’ specific surface and reduces the porosity of the granular mix, which enable the epoxy product to completely cover the surface of mineral grains. A perfect covering of aggregate grains with a bender improves the adhesion between the aggregates and the polymer matrix.


1987 ◽  
Vol 68 (3-4) ◽  
pp. 285-299 ◽  
Author(s):  
M. Koláč ◽  
B. S. Neganov ◽  
A. Sahling ◽  
S. Sahling

2021 ◽  
pp. 50-58
Author(s):  
V.A. Kuznetsova ◽  
◽  
V.G. Zheleznyak ◽  
S.L. Lonskii ◽  
N.A. Kovrizhkina ◽  
...  

Adhesion, physicomechanical properties, and also kinetics of water absorption of priming coatings on basis the E-41 epoxy resin modified by liquid Thiokol 1 and by Laproxide AF, and also their phase structure are investigated. As hardeners of primer compositions organic silicon ammine ASOT-2 and low-molecular polyamide PO-200 has been used. It is shown that use of the reactive modifier Laproxide AF and hardener ASOT-2 in the epoxy and thiokol film-formers allows to receive priming coating with uniform finely divided phase structure with low porosity and high water resistance.


2022 ◽  
pp. 132359
Author(s):  
Jingya Liu ◽  
Sidian Zhang ◽  
Xiuying Zhao ◽  
Yi Lu ◽  
Meng Song ◽  
...  

2013 ◽  
Vol 31 (No. 4) ◽  
pp. 361-367 ◽  
Author(s):  
A.G. Tafti ◽  
S.H. Peighardoust ◽  
F. Behnam ◽  
A. Bahrami ◽  
R. Aghagholizadeh ◽  
...  

The effect of incorporating different levels of spray-dried sourdough (3, 6, 9, and 15% w/w) on flour characteristics and dough properties of two wheat flours was studied. As the spray-dried sourdough level in the blends increased, the pH values significantly (P < 0.05) decreased. Wet gluten content and sedimentation values were decreased in the flours containing spray-dried sourdough compared to those of the control. Water absorption significantly increased compared to that of the control. However, the dough development time was not affected by sourdough powder addition. Degree of softening significantly increased with an increase in the sourdough level and dough stability was significantly reduced. Doughs incorporating sourdough powder showed higher resistance to extension and lower dough extensibility than the control doughs.  


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