scholarly journals The Use of Copper Oxides as Cross-Linking Substances for Chloroprene Rubber and Study of the Vulcanizates Properties. Part II. The Effect of Filler Type on the Properties of CR Products

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6528
Author(s):  
Aleksandra Smejda-Krzewicka ◽  
Piotr Kobędza ◽  
Krzyssztof Strzelec ◽  
Agnieszka Adamus-Włodarczyk

The properties of rubber materials are dependent on the characteristics of the elastomer matrix, the filler type, the cross-linking agent, the number of ingredients, and their interactions. In the previous article, we showed that chloroprene rubber can be efficiently cross-linked with copper(I) oxide or copper(II) oxide. During the processing of rubber compounds, the incorporation of a filler and a curing substance are two substantial parameters, such as the homogeneity of mixing and cross-linking that significantly affect the properties of the vulcanizates. Therefore, this work aimed to evaluate the curing characteristics, mechanical and dynamical properties, morphology, and flammability of the composites containing chloroprene rubber cross-linked with Cu2O or CuO and filled with different fillers (silica, carbon black, montmorillonite, kaolin, chalk). It was found that the type of filler and curing agent had a significant impact on the degree of cross-linking of the chloroprene rubber and the properties of its vulcanizates. The degree and speed of the cross-linking of filled CR were higher when the CR was cured with copper(II) oxide. Among the fillers used, the presence of carbon black or silica ensured the highest degree of CR cross-linking and the most useful properties. The flammability tests indicated that all produced vulcanizates were characterized by a high oxygen index, which allows them to be classified as non-flammable materials.

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1992 ◽  
Author(s):  
Alexey Kondyurin ◽  
Anastasia Eliseeva ◽  
Alexander Svistkov

A model of rubber with a cross-linked rubber layer on a carbon black filler has been proposed. The cross-links are the result of free radical reactions generated by carbon atoms with unpaired electrons at the edge of graphitic sheets in a carbon black filler. The experimental study of the cross-linking reactions in polyisoprene was done on a flat carbonized surface after ion beam implantation. The cross-linking process in the polyisoprene macromolecules between two particles was simulated. The model with a cross-linked rubber layer on a carbon filler as a “glassy layer” explains the mechanical properties of the rubber materials.


2019 ◽  
Vol 138 (6) ◽  
pp. 4395-4405 ◽  
Author(s):  
Anna Dziemidkiewicz ◽  
Magdalena Maciejewska ◽  
Martyna Pingot

Abstract The aim of this work was to examine the influence of new curing agents proposed for brominated butyl rubber (BIIR) on the cross-linking process of rubber compounds and the thermal behavior of the vulcanizates. Rubber blends that were filled with carbon black and contained acetylacetonates of different transition metals in the presence of triethanolamine (TEOA) as new cross-linking agents were prepared. The performed studies showed that metal acetylacetonates (Me(acac)) are effective cross-linking agents for BIIR, which was confirmed by high values of the torque increment (∆M) and significant cross-linking degree of the vulcanizates (α(T)). The most active curing agent seems to be iron acetylacetonate (Fe(acac)). Its application results in a shorter optimal vulcanization time, lower onset vulcanization temperature and similar vulcanization enthalpy compared to the BIIR cured with a sulfur curing system. The BIIR vulcanizates cured with Me(acac) reveal good mechanical properties with tensile strengths in the range of 9–14 MPa and better damping properties comparing to the sulfur-cured rubber. The proposed curing agents do not significantly affect the thermal stability of the BIIR vulcanizates.


2018 ◽  
Vol 91 (2) ◽  
pp. 492-508 ◽  
Author(s):  
L. M. Polgar ◽  
J. Keizer ◽  
R. Blom ◽  
B. Niemeijer ◽  
T. de With ◽  
...  

ABSTRACT It is demonstrated that the concept of thermoreversible cross-linking of functionalized maleic anhydride grafted ethylene–propylene (EPM-g-MA) rubber using Diels–Alder chemistry is limited neither to laboratory scale using a solvent route nor to gum rubber. The use of an internal mixer is the first step toward an industrial process, since it greatly reduces the processing time and allows for a solventless process for the furan-functionalization and subsequent bismaleimide cross-linking of EPM rubber. Practical rubber compounds were prepared by mixing thermoreversibly cross-linked EPM with carbon black and mineral oil in the same batch mixer. This resulted in reinforcement of the rubber without affecting the thermoreversible character of the cross-linking. The pendant furan groups of the (non)cross-linked EPM-g-furan interact with the carbon black filler. Finally, crystalline EPM rubber compounds were prepared, which show excellent material properties and property retention over multiple reprocessing cycles.


2021 ◽  
Vol 903 ◽  
pp. 119-126
Author(s):  
Sintija Eglite ◽  
Astrida Berzina ◽  
Māris Knite

Ethylene-vinyl acetate (EVA) and highly structured carbon black (CB) composites are promising for self-regulating heating materials, especially, were flexibility is needed. Two types of EVA-CB composites were made. Firstly, non-cross-linked EVA-CB composite was made with different CB concentrations and secondly, cross-linked EVA-CB composite with dicumylperoxide (DCP) as the cross-linking agent. Different concentrations of DCP were used. Samples were tested in two ways – by heating them internally (by applying 5V voltage) and externally (by heating in universal heating oven). The electro-thermal properties (including PTC effect) were determined.


2018 ◽  
Vol 157 ◽  
pp. 07007 ◽  
Author(s):  
Darina Ondrušová ◽  
Slavomíra Božeková ◽  
Lenka Buňová ◽  
Mariana Pajtášová ◽  
Ivan Labaj ◽  
...  

The present paper deals with a targeted modification of two kinds of alternative additives - waste from glass production and natural mineral filler and explores their effect on the properties of polymeric materials. In the function of first alternative filler was used sludge from weighing the ingredients of glass batch in the glass production. The second used was natural aluminosilicate material based on zeolite (clinoptilolite). These alternative fillers have been modified in order to increase its efficiency, using the silanes: 3-aminopropyl-triethoxysilane, bis(triethoxysilyl)propyl-tetrasulfide and 3-(triethoxysilyl)propyl-methacrylate. In the case of alternative filler based on zeolite the influence of silanization conditions on the filler efficiency have been also studied. Prepared modified fillers were mixed into rubber compounds as partial replacement of commonly used filler – carbon black. The influence of prepared fillers on rheology and curing characteristics of rubber compounds and also on physical and mechanical properties of vulcanizates has been studied. Obtained results of measured characteristics of polymeric systems containing prepared alternative fillers were compared with the results obtained in the case of reference rubber compound with a commertially used filler – carbon black.


1952 ◽  
Vol 25 (3) ◽  
pp. 557-572
Author(s):  
C. W. Sweitzer ◽  
Francis Lyon

Abstract Previous investigations have shown a large difference between the amount of rubber insolubilized by carbon black in dilute solvent systems and in standard mill mixes. The purpose of this study, after reconciling these extremes, was to evaluate the role of adsorption in the insolubilization of rubber in mill-mixed compounds. An adsorption test was employed which eliminated the solvent effect of the dilute system and the mastication effect in mill mixing. Results showed that carbon black, depending on the temperature and atmosphere conditions imposed on the rubber carbon films, represses the scission, cross-linking, and gelation reactions of GR-S X-478. This repressive effect is ascribed to the adsorption and inactivation by the carbon black of the oxidized intermediates through which these various reactions proceed. The magnitude of this effect was found to vary with the type, loading, and surface chemistry of the carbon. This approach not only offers promise as a means for predicting the behavior of carbon black in rubber compounds, but also, because of its applicability to the study of all rubber-carbon systems, offers possibilities of providing additional information on the mechanism of the carbon-rubber bond.


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