Barium and strontium ferrite-filled composites based on NBR and SBR

2018 ◽  
Vol 51 (5) ◽  
pp. 421-439 ◽  
Author(s):  
Ján Kruželák ◽  
Martina Matvejová ◽  
Rastislav Dosoudil ◽  
Ivan Hudec
Keyword(s):  
Barium Ferrite ◽  
Strontium Ferrite ◽  
Styrene Butadiene Rubber ◽  
Magnetic Characteristics ◽  
Butadiene Rubber ◽  
Magnetic Composites ◽  
Link Density ◽  
Cross Link Density ◽  
The Cross ◽  
Styrene Butadiene

In the first part of the research, rubber magnetic composites were prepared by incorporation of strontium and barium ferrite in concentration scale ranging from 0 to 200 phr into rubber matrices based on acrylonitrile–butadiene rubber and styrene–butadiene rubber. The main objective was to investigate the influence of the type and content of magnetic filler on the cross-link density, physical–mechanical and magnetic characteristics of the prepared composites. In the second part of the study, the content of magnetic fillers was kept on constant level—200 phr and the main aim was to investigate the change in mutual combination of both fillers on the cross-linking and properties of the rubber magnets. The results revealed that both fillers show reinforcement effect in the rubber matrices. The higher tensile strength of composites was achieved by application of barium ferrite. Magnetic properties of composite materials were significantly influenced by magnetic characteristics of magnetic fillers. Higher remanent magnetic induction of barium ferrite was reflected in higher remanent magnetization of the equivalent composites. On the other hand, higher coercivity of strontium ferrite resulted in higher coercivity of strontium ferrite-filled composites.

Thermooxidative aging of rubber composites based on NR and NBR with incorporated strontium ferrite

2017 ◽  
Vol 50 (1) ◽  
pp. 71-91 ◽  
Author(s):  
Ján Kruželák ◽  
Rastislav Dosoudil ◽  
Ivan Hudec
Keyword(s):  
Strontium Ferrite ◽  
Rubber Matrix ◽  
Magnetic Characteristics ◽  
Butadiene Rubber ◽  
Cross Link ◽  
Magnetic Composites ◽  
Aging Period ◽  
Link Density ◽  
Cross Link Density ◽  
The Cross

Rubber magnetic composites were prepared by incorporation of strontium ferrite in concentration scale ranging from 0 phr to 100 phr into rubber matrices based on natural rubber (NR) and acrylonitrile-butadiene rubber (NBR). The composite systems were exposed to the conditions of thermooxidative aging at 70°C for 7, 14, and 28 days. The influence of aging period on the behavior of prepared materials was considered based on investigation of their cross-link density, physical–mechanical, and magnetic characteristics. The results revealed that the influence of thermooxidative aging on composite characteristics is dependent on the type of rubber matrix. The thermooxidative aging was found to have negative effect on the cross-link density and tensile properties of composites based on NR, which were deteriorated in dependence of aging time. The possible influence of magnetic filler content on aging mechanism was observed during last period of aging after which the decrease in cross-link density and tensile characteristics was more pronounced with increasing content of strontium ferrite. By contrast, the cross-link density, modulus, and hardness of composites based on NBR were found to be positively influenced by aging as their values showed increasing trend with extension of aging period.

Rubber magnets cured with peroxide and coagents

2019 ◽  
Vol 52 (3) ◽  
pp. 253-270
Author(s):  
Andrea Kvasničáková ◽  
Ján Kruželák ◽  
Elena Medlenová ◽  
Rastislav Dosoudil ◽  
Ivan Hudec ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Styrene Butadiene Rubber ◽  
Cross Linking ◽  
Butadiene Rubber ◽  
Cross Link ◽  
Magnetic Composites ◽  
Peroxide Curing ◽  
Link Density ◽  
Cross Link Density ◽  
Styrene Butadiene

Barium ferrite in constant amount (50 phr) was incorporated into styrene-butadiene rubber to prepare rubber magnetic composites. Dicumyl peroxide was used as a curing agent for cross-linking of the prepared composites. Four different types of low-molecular-weight organic compounds were applied as coagents to enhance the efficiency of cross-linking process and to improve the compatibility between the rubber and the filler on the interphase. The main goal of this work was to investigate the influence of the composition of peroxide curing system on cross-link density, physical–mechanical and magnetic properties of the composites. The results revealed that the type and amount of coagents have no influence on magnetic properties of the rubber magnets. On the other hand, cross-link density and physical–mechanical properties were significantly dependent on the composition of curing system. The increase of tensile strength can be attributed to the improvement of adhesion on the interphase filler–rubber due to the presence of coagents.

scholarly journals Magnetic composites based on NR and strontium ferrite

2019 ◽  
Vol 12 (1) ◽  
pp. 63-69
Author(s):  
Ján Kruželák ◽  
Andrea Kvasničáková ◽  
Rastislav Dosoudil ◽  
Ivan Hudec
Keyword(s):  
Carbon Black ◽  
Strontium Ferrite ◽  
Rubber Matrix ◽  
Cross Link ◽  
Magnetic Composites ◽  
Link Density ◽  
Cross Links ◽  
Cross Link Density ◽  
The Cross ◽  
Thermo Physical Properties

Abstract Two types of composites based on natural rubber (NR) and strontium ferrite were tested in this study. Composites of the first type were prepared by incorporation of strontium ferrite in the concentration range ranging from 0 to 100 phr (parts per hundred rubber) into pure NR based rubber matrix, while with those of the second type, strontium ferrite was dosed in the same concentration level into NR based rubber batch with constant amount of carbon black — 25 phr. For rubber matrices cross-linking, a standard sulfur based curing system was used. This work is focused on the effect of magnetic filler content on physico-mechanical, magnetic and thermo-physical properties of composite materials. Subsequently, the cross-link density and the structure of the formed sulfidic cross-links were examined. The results showed that the cross-link density of both types of composites increased with the increasing content of magnetic filler, while the structure of the sulfidic cross-links was almost not influenced by the amount of strontium ferrite. Tensile strength of rubber composites with pure rubber matrix was slightly improved by the incorporation of ferrite, while in case of composites based on a carbon black batch, the incorporation of magnetic filler resulted in the decrease of this characteristic. The presence of magnetic filler in both types of composites leads to a significant increase of the remanent magnetic induction.

scholarly journals Influence of trans-polyoctylene rubber content on styrene-butadiene rubber properties

2020 ◽  
Vol 13 (1) ◽  
pp. 1-5
Author(s):  
Patrik Macúrik ◽  
Rafal Anyszka ◽  
Ivan Hudec ◽  
Terézia Malčeková ◽  
Ján Kruželák
Keyword(s):  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Curing Time ◽  
Cross Link ◽  
Rubber Content ◽  
Elongation At Break ◽  
Rubber Compounds ◽  
Link Density ◽  
Cross Link Density ◽  
Styrene Butadiene

AbstractThe study was focused on the investigation of trans-polyoctylene (TOR) influence on cross-linking as well as mechanical and rheological properties of rubber compounds based on styrene-butadiene rubber (SBR). SBR was compounded with different proportions of TOR in the concentration range from 0 to 30 phr. Integration of TOR into rubber leads to the prolongation of the optimum curing time and scorch time and thus the decrease of the curing rate. Higher content of TOR led to less viscous rubber due to the plasticizing effect. Cross-link density of vulcanizates was reduced, which correlates with higher elongation at break. Tensile strength and hardness of vulcanizates increased with the increasing TOR content, probably due to the increasing amount of the crystalline phase.

scholarly journals Reinforcement of Rubber Magnetic Composites with Zinc Salts of Acrylic and Methacrylic Acids

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2161 ◽  
Author(s):  
Ján Kruželák ◽  
Viera Karlíková ◽  
Rastislav Dosoudil ◽  
Katarína Tomanová ◽  
Ivan Hudec
Keyword(s):  
Magnetic Properties ◽  
Mechanical Characteristics ◽  
Strontium Ferrite ◽  
Cross Linking ◽  
Butadiene Rubber ◽  
Magnetic Composites ◽  
Peroxide Curing ◽  
Link Density ◽  
Zinc Salts ◽  
Cross Link Density

Strontium ferrite was compounded with acrylonitrile butadiene rubber to prepare rubber magnetic composites. For cross-linking of the prepared materials, peroxide curing systems consisting of dicumyl peroxide as curing agent and zinc salts of acrylic and methacrylic acids as co-agents were used. The amount of strontium ferrite was kept constant in all experiments, while the main objective of the work was to investigate the composition of curing system and both types of co-agents on the cross-linking, physical-mechanical, dynamic and magnetic properties of the rubber magnets. The results showed that the change in composition of curing system has significant influence on cross-link density and properties of the tested composite materials. With an increasing amount of zinc based co-agents, significant improvement of tensile strength was achieved. The application of zinc based co-agents in peroxide vulcanization of rubber magnetic composites leads to the preparation of rubber magnets with not only good magnetic properties, but also with improved physical-mechanical characteristics.

Relationship between the cross-link structure and properties of peroxide and sulfur-cured magnetic composites based on NR and NBR

2016 ◽  
Vol 49 (6) ◽  
pp. 459-480 ◽  
Author(s):  
Ján Kruželák ◽  
Richard Sýkora ◽  
Rastislav Dosoudil ◽  
Ivan Hudec
Keyword(s):  
Cross Linking ◽  
Butadiene Rubber ◽  
Cross Link ◽  
Magnetic Composites ◽  
Link Structure ◽  
Link Density ◽  
Cross Link Density ◽  
The Cross ◽  
The Relationship ◽  
Curing Systems

In the present work, rubber magnetic composites were prepared by incorporation of strontium ferrite into rubber matrices based on natural rubber (NR) and acrylonitrile butadiene rubber (NBR). The sulfur and peroxide curing systems were introduced in cross-linking of rubber matrices. The research was aimed at the evaluation of magnetic filler content and type of curing system on the cross-link density, physical–mechanical and magnetic properties of prepared composites. The relationship between the composition of elastomers and cross-link structure within the rubber matrices, formed by applying different curing systems, was under investigation through strain–stress behavior of tested materials. The achieved results showed that ferrite behaves as a reinforcing filler in peroxide-cured composites based on NR, and in both, sulfur as well as peroxide-cured composites based on NBR. The results also demonstrated that the cross-linking degree and the type of cross-link structure as well as the composition of rubber matrices, to a large extent, influence the property spectrum of tested composite systems.

scholarly journals Application of Peroxide Curing Systems in Cross-Linking of Rubber Magnets Based on NBR and Barium Ferrite

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Ján Kruželák ◽  
Andrea Kvasničáková ◽  
Elena Medlenová ◽  
Rastislav Dosoudil ◽  
Ivan Hudec
Keyword(s):  
Mechanical Properties ◽  
Barium Ferrite ◽  
Cross Linking ◽  
Butadiene Rubber ◽  
Cross Link ◽  
System Composition ◽  
Peroxide Curing ◽  
Link Density ◽  
Cross Link Density ◽  
Curing Systems

Rubber magnetic composites were prepared by incorporation of barium ferrite in constant amount—50 phr into acrylonitrile-butadiene rubber. Dicumyl peroxide as the curing agent was used for cross-linking of rubber magnets alone, or in combination with four different types of co-agents. The main aim was to examine the influence of curing system composition on magnetic and physical-mechanical properties of composites. The cross-link density and the structure of the formed cross-links were investigated too. The results demonstrated that the type and amount of the co-agent had significant influence on cross-link density, which was reflected in typical change of physical-mechanical properties. The tensile strength increased with increasing amount of co-agents, which can be attributed to the improvement of adhesion and compatibility on the interphase filler-rubber due to the presence of co-agents. Magnetic characteristics were found not to be influenced by the curing system composition. The application of peroxide curing systems consisting of organic peroxide and co-agents leads to the preparation of rubber magnets with not only good magnetic properties but also with improved physical-mechanical properties, which could broaden the sphere of their application uses.

scholarly journals COMPARATIVE INVESTIGATION OF THE DEVULCANIZATION PARAMETERS OF TIRE RUBBERS

2014 ◽  
Vol 87 (1) ◽  
pp. 31-42 ◽  
Author(s):  
S. Saiwari ◽  
W. K. Dierkes ◽  
J. W. M. Noordermeer
Keyword(s):  
Polymer Network ◽  
Comparative Investigation ◽  
High Ratio ◽  
Styrene Butadiene Rubber ◽  
Process Conditions ◽  
Moderate Increase ◽  
Butadiene Rubber ◽  
Cross Link ◽  
Link Density ◽  
Cross Link Density

ABSTRACT The optimal process conditions for a high ratio of devulcanization to polymer degradation have been investigated for tire rubbers: styrene–butadiene rubber (SBR), butadiene rubber (BR), natural rubber (NR), and chloro-isobutylene–isoprene rubber (CIIR). These polymers all show their own particular breakdown characteristics. The temperature dependence of the breakdown mechanism was investigated by measuring sol fractions and cross-link densities. For SBR and BR, the highest reduction in cross-link density was found at a temperature of 220 °C, together with a moderate increase in sol content. According to the Horikx theory, which correlates sol fraction and a decrease in cross-link density, this is the result of a high degree of cross-link scission. Higher process temperatures result in a lower decrease in cross-link density due to recombination of active chain fragments. NR and CIIR show different behavior. Breakdown of NR in this temperature range results in an almost complete destruction of the polymer network; cross-link density is reduced to almost zero, and the sol fraction is close to 100%. The same result is found for CIIR at higher temperatures. Although different rubbers react via other devulcanization mechanisms, the best devulcanization conditions for whole passenger car tire material are optimized.

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