Vulcanization of Butadiene Rubber by Means of Cyclic Disulfides. 1. A 2D NMR Study on the Cross-Link Structure of a BR Model Compound Vulcanizate

1999 ◽  
Vol 32 (22) ◽  
pp. 7504-7508 ◽  
Author(s):  
Roger M. Seyger ◽  
Ron Hulst ◽  
John P. M. van Duynhoven ◽  
Robin Winters ◽  
Leen van der Does ◽  
...  
Keyword(s):  
Model Compound ◽  
2D Nmr ◽  
Butadiene Rubber ◽  
Cross Link ◽  
Link Structure ◽  
Nmr Study ◽  
The Cross

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.

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.

INFLUENCE OF END-FUNCTIONALIZED SOLUTION STYRENE–BUTADIENE RUBBER ON SILICA-FILLED VULCANIZATES WITH VARIOUS SILICA–SILANE SYSTEMS

2018 ◽  
Vol 92 (2) ◽  
pp. 364-377 ◽  
Author(s):  
Byungkyu Ahn ◽  
Nam Park ◽  
Donghyuk Kim ◽  
Wonho Kim
Keyword(s):  
Physical Properties ◽  
Coupling Agent ◽  
Functional Group ◽  
Silica Content ◽  
Alkoxy Group ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Cross Link ◽  
The Cross ◽  
Styrene Butadiene

ABSTRACT We investigated how end-functionalized solution styrene–butadiene rubber (SSBR) affects the vulcanizate structures and the physical properties of silica-filled vulcanizates using non-functionalized and end-functionalized SSBRs with aminopropylalkoxysilane. Two silane agents were used. Triethoxy(octyl)silane was used as a covering agent, and bis-[3-(triethoxysilyl)propyl]disulfide was applied as a coupling agent. The effects of three different silica–silane systems with a covering agent (CV), a coupling agent (CP), or with no silane (NS) were analyzed. In the CV and NS systems, the cross-link densities induced by the polymer and curing system were similar with respect to the end-functionalization. Further, the cross-link densities induced by the silica–silane system were similar, regardless of the end-functionalization. However, the CP system exhibited similar cross-link densities, irrespective of functionalization. Both the coupling agent and end-functional group chemically bonded with the silanol groups of silica, thus competing with each other and affecting the vulcanizate structure. However, increasing the silica content decreased the effect of end-functionalization because the content of the coupling agent increased, and the end-functional group was less mobile than the coupling agent's alkoxy group.

scholarly journals Elucidation of the Cross-Link Structure of Nadic-End-Capped Polyimides Using NMR of13C-Labeled Polymers

1997 ◽  
Vol 30 (3) ◽  
pp. 515-519 ◽  
Author(s):  
Mary Ann B. Meador ◽  
J. Christopher Johnston ◽  
Paul J. Cavano
Keyword(s):  
Cross Link ◽  
Link Structure ◽  
The Cross

Vulcanization of Butadiene Rubber by Means of Cyclic Disulfides. 2. A 2D Solid State HRMAS NMR Study on Cross-Link Structures in BR Vulcanizates

1999 ◽  
Vol 32 (22) ◽  
pp. 7509-7520 ◽  
Author(s):  
Ron Hulst ◽  
Roger M. Seyger ◽  
John P. M. van Duynhoven ◽  
Leen van der Does ◽  
Jacques W. M. Noordermeer ◽  
...  
Keyword(s):  
Solid State ◽  
Butadiene Rubber ◽  
Cross Link ◽  
Nmr Study ◽  
Hrmas Nmr

scholarly journals Microtubules and microtubule-associated proteins from the nematode Caenorhabditis elegans: periodic cross-links connect microtubules in vitro.

1986 ◽  
Vol 103 (1) ◽  
pp. 23-31 ◽  
Author(s):  
E J Aamodt ◽  
J G Culotti
Keyword(s):  
Caenorhabditis Elegans ◽  
Apparent Molecular Weight ◽  
Cross Link ◽  
Nematode Caenorhabditis Elegans ◽  
Microtubule Associated Proteins ◽  
C Elegans ◽  
Associated Proteins ◽  
Cross Links ◽  
The Cross

The nematode Caenorhabditis elegans should be an excellent model system in which to study the role of microtubules in mitosis, embryogenesis, morphogenesis, and nerve function. It may be studied by the use of biochemical, genetic, molecular biological, and cell biological approaches. We have purified microtubules and microtubule-associated proteins (MAPs) from C. elegans by the use of the anti-tumor drug taxol (Vallee, R. B., 1982, J. Cell Biol., 92:435-44). Approximately 0.2 mg of microtubules and 0.03 mg of MAPs were isolated from each gram of C. elegans. The C. elegans microtubules were smaller in diameter than bovine microtubules assembled in vitro in the same buffer. They contained primarily 9-11 protofilaments, while the bovine microtubules contained 13 protofilaments. The principal MAP had an apparent molecular weight of 32,000 and the minor MAPs were 30,000, 45,000, 47,000, 50,000, 57,000, and 100,000-110,000 mol wt as determined by SDS-gel electrophoresis. The microtubules were observed, by electron microscopy of negatively stained preparations, to be connected by stretches of highly periodic cross-links. The cross-links connected the adjacent protofilaments of aligned microtubules, and occurred at a frequency of one cross-link every 7.7 +/- 0.9 nm, or one cross-link per tubulin dimer along the protofilament. The cross-links were removed when the MAPs were extracted from the microtubules with 0.4 M NaCl. The cross-links then re-formed when the microtubules and the MAPs were recombined in a low salt buffer. These results strongly suggest that the cross-links are composed of MAPs.

Two-dimensional NMR studies of acrylate copolymers

2009 ◽  
Vol 81 (3) ◽  
pp. 389-415 ◽  
Author(s):  
A. S. Brar ◽  
Ashok Kumar Goyal ◽  
Sunita Hooda
Keyword(s):  
Methyl Methacrylate ◽  
Methyl Acrylate ◽  
Quantum Coherence ◽  
Multiple Bond ◽  
Microstructural Analysis ◽  
2D Nmr ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Poly Methyl Methacrylate ◽  
Nmr Study

High-resolution NMR spectroscopy is the most versatile, reliable, and generally acceptable technique for the determination of the microstructure of polymers. 2D NMR techniques, along with 1D NMR, have more potential to study absolute configurational assignments and sequence distribution of copolymers. Physical and chemical properties of polymers are influenced fundamentally by their microstructure. We discuss the detailed microstructure analysis of a large number of homopolymers, copolymers, and terpolymers. 2D NMR study of poly(methyl methacrylate) (PMMA), poly(methyl acrylate) (PMA), and poly(methacrylonitrile) (PMAN) is discussed in this article. In addition to homopolymers, 2D heteronuclear single-quantum coherence (HSQC), total correlation spectroscopy (TOCSY), and heteronuclear multiple-bond correlation (HMBC) study of different copolymers such as poly(methyl methacrylate-co-methyl acrylate), poly(styrene-co-methyl methacrylate), and poly(methyl methacrylate-co-methacrylonitrile) have also been reported here. This in turn helps in microstructural analysis of terpolymers such as poly(methacrylonitrile-co-styrene-co-methyl methacrylate), poly(acrylonitrile-co-methyl methacrylate-co-methyl acrylate), and poly(ethylene-co-vinyl acetate-co-carbon monoxide).

Sign in / Sign up

Export Citation Format

Share Document