HIGH-THROUGHPUT KINETIC STUDY OF PEROXIDE CURING OF EPDM RUBBER

2011 ◽  
Vol 84 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Johannes M. Kranenburg ◽  
Martin Van Duin ◽  
Ulrich S. Schubert
Keyword(s):  
Raman Spectroscopy ◽  
High Throughput ◽  
Hardness Measurement ◽  
Cross Link ◽  
High Throughput Experimentation ◽  
Peroxide Curing ◽  
Link Density ◽  
Cross Link Density ◽  
Solution Route ◽  
Set Up

Abstract Mixing of EPDM and a peroxide curative via a solution route and subsequent curing were performed in a downscaled set-up. The resulting vulcanizates were characterized by a down-scaled hardness measurement and by Raman spectroscopy in a high-throughput experimentation compatible approach. The characterization results obtained on these vulcanizates agreed well with those obtained on corresponding vulcanizates prepared via conventional mill mixing. By indentation on vulcanizates cured for various curing times, a rheometer curve could be constructed. The conversion of the EPDM unsaturation and, thus, the extent of the addition reactions was quantified by Raman spectroscopy. Using both the indentation and the Raman data, the cross-link density resulting from combination reactions was estimated.

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.

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.

Boron nitride for modification of rubber based on isoprene elastomer

2020 ◽  
pp. 105-112
Author(s):  
K. S. Zhansakova ◽  
E. N. Eremin ◽  
G. S. Russkikh ◽  
O. V. Kropotin
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Gradual Increase ◽  
Physical And Mechanical Properties ◽  
Curing Time ◽  
Cross Link ◽  
Start Time ◽  
Link Density ◽  
Cross Link Density ◽  
Isoprene Rubber

The work studies vulcanization characteristics of elastomers based on isoprene rubber filled with carbon black N330 and boron nitride (BN). The influence of the boron nitride (BN) concentration on technological, dynamic, physical and mechanical properties of elastomers has been researched. The application of boron nitride for producing rubber with good properties has been considered. With a gradual increase of the inert filler BN concentration up to 35%, a decrease in the curing rate by 33% and polymer cross-link density by 26% is observed. Moreover, the start time of vulcanization increases by almost 300%, the optimal curing time by 200%.

Mechanical and structural consequences of associative dynamic cross-linking in acrylic diblock copolymers

2021 ◽  
Author(s):  
Jacob Ishibashi ◽  
Ian Pierce ◽  
Alice Chang ◽  
Aristotelis Zografos ◽  
Bassil El-Zaatari ◽  
...  
Keyword(s):  
Viscoelastic Properties ◽  
Diblock Copolymers ◽  
Microphase Separation ◽  
Network Connectivity ◽  
Ethyl Acrylate ◽  
Cross Linking ◽  
Cross Link ◽  
Block Polymers ◽  
Link Density ◽  
Cross Link Density

<p>The composition of low-T<sub>g</sub> <i>n</i>-butylacrylate-<i>block</i>-(acetoxyaceto)ethyl acrylate block polymers is investigated as a strategy to tune the properties of dynamically cross-linked vinylogous urethane vitrimers. As the proportion of the cross-linkable block is increased, the thermorheological properties, structure, and stress relaxation evolve in ways that cannot be explained by increasing cross-link density alone. Evidence is presented that network connectivity defects such as loops and dangling ends are increased by microphase separation. The thermomechanical and viscoelastic properties of block copolymer-derived vitrimers arise from the subtle interplay of microphase separation and network defects.</p><div><br></div><p></p>

Mechanical behavior of poly(methyl methacrylate)-based ionogels

Soft Matter ◽  
2014 ◽  
Vol 10 (40) ◽  
pp. 7993-8000 ◽  
Author(s):  
Mingyu Li ◽  
Jianyu Li ◽  
Hui Na ◽  
Joost J. Vlassak
Keyword(s):  
Methyl Methacrylate ◽  
Mechanical Behavior ◽  
Fracture Energy ◽  
Cross Link ◽  
Poly Methyl Methacrylate ◽  
Link Density ◽  
Cross Link Density ◽  
The Cross ◽  
The Ideal

We demonstrate that the fracture energy of ionogels correlates inversely with the cross-link density. The behavior of ionogels is well captured by the ideal elastomeric gel model.

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.

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