2019 ◽  
Vol 24 (94/4) ◽  
pp. 27-32
Author(s):  
T.S. Skoblo ◽  
I.N. Rybalko ◽  
A.V. Tihonov ◽  
T.V. Maltsev

The possibility of using a non-magnetic fraction of a detonation charge with a diamond fraction from the disposal of ammunition to modify the restoration coatings of a natural product – clay and secondary raw materials — was studied. Four different coating variants were investigated. For this, a T-620 electrode was used with its additional modification by coating with bentonite clay, as well as with a non-magnetic fraction of the detonation charge and applying it in the form of a slip coating on the cutting surface of the cultivator. It is shown that the use of such additives allows to increase the resistance of the working tool of agricultural machines, reduces its tendency to damage due to the minimum penetration of the thin-walled product of the hoe blade and a decrease in the cross section of the transition layer and the level of stress. Each modifier makes changes to increase the microhardness to varying degrees. An increase in microhardness is observed on the surface of the coating and its gradual decrease to the transition layer. The surface coating with the additional introduction of bentonite clay in a liquid bath has the highest microhardness. Its microhardness varies from HV-50-1009.7 to HV-50-615.2. Similarly, the effect of the modifying additive of the detonation charge, the microhardness varies from HV-50-969.6 to HV-50-633.26. When clay or a mixture is introduced into the restoration coating, the wear resistance increases by 1.3 - 2 times with respect to the deposited surfacing only by the electrode and by 2 - 3 times to the initial material of the cultivator. It was found that the lowest coefficient is characteristic for dry friction, as well as for hydroabrasive, for samples with additional modification with clay or a detonation charge


Cellulose ◽  
2021 ◽  
Author(s):  
Peixin Tang ◽  
Leilah-Marie E. Lockett ◽  
Mengxiao Zhang ◽  
Gang Sun

AbstractA chemical modification of cotton fabrics by 2-diethylaminoethyl chloride (DEAE-Cl) was achieved, and the resulted cotton fabrics demonstrated salt-free dyeing properties with anionic dyes. Nucleophilic property of hydroxyl groups in cotton cellulose was enhanced under alkaline conditions and could react with DEAE-Cl, a chemical possessing both nucleophilic and electrophilic sites. The monolayered DEAE-grafted cotton cellulose could further react with DEAE-Cl to form multiple cationic quaternary ammonium salts (denoted as DEAE@Cotton), which are highly interactive with anionic dye molecules. The strong electrostatic interactions between the DEAE@Cotton and the dyes eliminated the use of inorganic salts in cotton dyeing process. The chemical structure and property of DEAE@Cotton were characterized and compared with untreated cotton. The DEAE@Cotton can be dyed in a salt-free system, and the dye exhaustion was faster than the conventional dyeing method due to the robust electrostatic interactions of the fabrics with anionic dyes. The dyed fabrics demonstrated outstanding color fastness under repeated washing, light exposure, and crocking. The dye adsorption process on DEAE@Cotton follows Langmuir isotherm model (R2 = 0.9667). The mechanism of enhanced dyeability was experimentally proved by treating the fabric with other anionic dyes in a salt-free system, proving the process to be environmentally friendly and cost-effective. Graphic abstract


2021 ◽  
Author(s):  
Madhvi Garg ◽  
Navneet Bhullar ◽  
Bharat Bajaj ◽  
Dhiraj Sud

The present manuscript reports the ultrasound radiation induced synthesis of grafted chitosan hydrogels (CAAT and CAAG) using terephthalaldehyde/glutaraldehyde as crosslinking agents and its application for removal of synthetic dyes from...


Data in Brief ◽  
2021 ◽  
Vol 35 ◽  
pp. 106799
Author(s):  
Khouloud Jlassi ◽  
Kamel Eid ◽  
Mostafa H. Sliem ◽  
Aboubakr M. Abdullah ◽  
Mohamed M. Chehimi

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