Dilatometric Measurement of the Rate of Vulcanization of Crepe Rubber by Sulfur Monochloride

Abstract The cold vulcanization of rubber by sulfur monochloride is believed to consist essentially of the cross-linking of adjacent polyisoprene units by a series of sulfide bonds. Chemical analysis of the product suggests that the cross-linking process is analogous to the mustard gas reaction of ethylene with sulfur monochloride, thus: (see PDF for diagram) Nothing is known, however, about the kinetics of this vulcanization process. General considerations lead one to expect that such a reaction, involving polymer aggregation, should be accompanied by an increase in the density of the rubber; moreover, by choosing a suitably delicate technique, it should be possible to utilize such density changes for rate determinations. A dilatometric method seemed most suitable, and the experiments described here show that the vulcanization process is, indeed, accompanied by a decrease in volume of the reaction mixture, and that the reaction may be followed quantitatively using a tap dilatometer.

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Vulcanization of Crepe Rubber by Sulfur Monochloride. II. The Dilatometric Method

Rubber Chemistry and Technology ◽

10.5254/1.3542847 ◽

1955 ◽

Vol 28 (3) ◽

pp. 850-864 ◽

Cited By ~ 1

Author(s):

J. Glazer

Keyword(s):

Cross Linking ◽

Kinetic Behavior ◽

High Dilution ◽

Dilute Solutions ◽

Volume Contraction ◽

Sulfur Monochloride ◽

Dilatometric Method ◽

The Cross ◽

Vulcanization Process ◽

Large Contraction

Abstract The vulcanization of rubber by sulfur monochloride is believed to consist of the cross-linking of adjacent isoprene units by thio-ether bonds. Such a reaction, involving polymer aggregation, should be accompanied by an increase of the density of the rubber, and, by choosing a suitably delicate technique, it should be possible to measure the rate of vulcanization by observing density changes. A dilatometric method seemed most suitable, and it was found that the reaction could indeed be followed by observing the rate of decrease of volume of the system rubber-sulfur monochloride when dissolved in a suitable solvent. Initial experiments showed that, during cold vulcanization, the system underwent a volume contraction which was of the order of 10 per cent with respect to the rubber. This comparatively large contraction allowed one to work with extremely dilute solutions (<0.3% w/w) of rubber. It thereby became possible to study the systems under more ideal kinetic conditions of high dilution than has been hitherto possible. In the present investigation, it has not been possible to do more than establish the broad outlines of the kinetic behavior of the system, and, on this basis, to propose feasible mechanisms for the cold vulcanization process.

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Interaction between Polyaramidic Electrospun Nanofibers and Epoxy Resin for Composite Materials Reinforcement

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.748.39 ◽

2017 ◽

Vol 748 ◽

pp. 39-44 ◽

Cited By ~ 4

Author(s):

Stefano Merighi ◽

Emanuele Maccaferri ◽

Juri Belcari ◽

Andrea Zucchelli ◽

Tiziana Benelli ◽

...

Keyword(s):

Composite Materials ◽

Epoxy Resin ◽

Electrospun Nanofibers ◽

Cross Linking ◽

Curing Process ◽

Electrospinning Technique ◽

Epoxy Matrix Composite ◽

The Cross ◽

Kinetics Of ◽

Composite Properties

Interaction between poly (m-phenylene isophtalamide) (PMIA) electrospun nanofibers and commercial epoxy resin precursor during the cross-linking process was investigated, in order to use such polyaramidic nanofibers for composite materials reinforcement. Hence nanofibrous PMIA mats were produced via electrospinning technique to be used for the functional modification of the epoxy matrix composite properties. When adding such fibers to an epoxy resin precursor, it was observed a strong influence on the kinetics of its curing process. The final results, however, demonstrates that boosting the reaction condition (raising the temperature and the reaction time) the curing is pushed to completion, indicating that the cross-linking process of the resin is just delayed and not completely hampered. It will be therefore necessary to rethink the composite cure cycle when PMIA nanofibers are added to the composite material, in order to attain significant improvement of the final composite performance.

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Cure Monitoring of Epoxy Resin by Simultaneous DSC/FTIR

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.881-883.905 ◽

2014 ◽

Vol 881-883 ◽

pp. 905-908

Author(s):

Li Wei Wang ◽

Gerard F. Fernando

Keyword(s):

Cross Linking ◽

Resin System ◽

Fibre Optic ◽

Cure Monitoring ◽

Epoxy Amine ◽

Fibre Optic Probe ◽

The Cross ◽

Optic Probe ◽

Conventional Dsc ◽

Kinetics Of

The cross-linking kinetics of an epoxy/amine resin system was studied using the conventional DSC and FTIR spectroscopy, respectively. Conventional DSC was modified to accommodate two fibre optic probes which could be used to monitor the spectra of epoxy/amine resin system during cure. The cross-linking kinetics for the epoxy/amine resin system obtained via the conventional DSC and FTIR and simultaneous DSC/FTIR were similar. The feasibility of using a simple bifurcated fibre optic probe to link the DSC to the FTIR spectrometer was demonstrated.

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Thermoreversible cross-linking of ethylene/propylene copolymers based on Diels–Alder chemistry: the cross-linking reaction kinetics

Polymer Chemistry ◽

10.1039/d0py01046d ◽

2020 ◽

Vol 11 (36) ◽

pp. 5851-5860

Author(s):

Shuhui Liu ◽

Xiaoyan Liu ◽

Zongke He ◽

Liying Liu ◽

Hui Niu

Keyword(s):

Reaction Kinetics ◽

Diels Alder ◽

Cross Linking ◽

Ethylene Propylene ◽

Rheological Method ◽

The Cross ◽

Kinetics Of

The kinetics of the cross-linking reaction of ethylene/propylene rubbers based on Diels–Alder chemistry was detected by the rheological method.

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Cationic cellulose hydrogels: kinetics of the cross-linking process and characterization as pH-/ion-sensitive drug delivery systems

Journal of Controlled Release ◽

10.1016/s0168-3659(02)00410-8 ◽

2003 ◽

Vol 86 (2-3) ◽

pp. 253-265 ◽

Cited By ~ 131

Author(s):

Rosalı́a Rodrı́guez ◽

Carmen Alvarez-Lorenzo ◽

Angel Concheiro

Keyword(s):

Drug Delivery ◽

Drug Delivery Systems ◽

Delivery Systems ◽

Cross Linking ◽

The Cross ◽

Kinetics Of

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Volume growth, murein synthesis, and murein cross-linkage during the division cycle of Escherichia coli PA3092

Journal of Bacteriology ◽

10.1128/jb.152.3.1248-1254.1982 ◽

1982 ◽

Vol 152 (3) ◽

pp. 1248-1254

Author(s):

A J Olijhoek ◽

S Klencke ◽

E Pas ◽

N Nanninga ◽

U Schwarz

Keyword(s):

Escherichia Coli ◽

Sodium Dodecyl ◽

Volume Growth ◽

Diaminopimelic Acid ◽

Cross Linking ◽

Penicillin Binding Protein ◽

Whole Cells ◽

Cross Linkage ◽

The Cross ◽

Kinetics Of

Cells of Escherichia coli PA3092 were synchronized by centrifugal elutriation. The synchronously growing cells were double labeled with -3H or DL-[meso-2,6-14C]diaminopimelic acid (DAP) at different times. Cells incorporated [3H]DAP at a continuously increasing rate during their cycle, with a maximum occurring at about 30 min before division for trichloroacetic acid-precipitated cells (whole cells) and about 10 min before division for sodium dodecyl sulfate-treated cells (sacculi). This was in good agreement with the observed kinetics of volume growth under these conditions. Furazlocillin, which preferentially interacts with penicillin-binding protein 3, modified the pattern of incorporation of [3H]DAP. Electron microscopy indicated that furazlocillin did not inhibit the initiation of division but rather its completion. In addition, we measured the cross-linking of the murein inserted at different times during synchronous growth. The highest percentages were found to occur around division. At this same time, the cross-linking of old peptidoglycan was found to be decreased.

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Ionic Liquids Applied to Improve the Dispersion of Coagent Particles in an Elastomer

Journal of Composites ◽

10.1155/2013/286534 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Magdalena Maciejewska ◽

Marian Zaborski

Keyword(s):

Ionic Liquids ◽

Alkyl Chain ◽

Cross Linking ◽

Cross Link ◽

Rubber Compounds ◽

Link Density ◽

Vulcanization Kinetics ◽

Cross Link Density ◽

The Cross ◽

Kinetics Of

The aim of this work was to study the activity of several ionic liquids (alkylimidazolium salts) that are used to improve the dispersion of coagent particles in peroxide-cross-linked hydrogenated acrylonitrile butadiene elastomer (HNBR). Hydrotalcite grafted with monoallyl maleate was applied as a coagent for the HNBR vulcanization. In this paper, we discuss the effect of the ionic liquids (alkylimidazolium salts) with respect to their anion (bromide, chloride, tetrafluoroborate, and hexafluorophosphate) and the length of alkyl chain in the cation (allyl-, ethyl-, butyl-, hexyl-, and octyl-) on the vulcanization kinetics of rubber compounds. The influence of ionic liquids on the cross-link density, the mechanical properties of the vulcanizates, and their resistance to weather ageing were also studied. Alkylimidazolium salts seem to improve the dispersion of the coagent particles and to be active in the cross-linking of HNBR with peroxide. The type of ionic liquid considerably influences the activity of the coagent particles toward the HNBR. The application of ionic liquids increases the cross-link density of the vulcanizates and improves their resistance to weather aging.

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Intrastrand Bifunctional Alkylation of DNA in Mammalian Cells Treated with Mustard Gas

Canadian Journal of Biochemistry ◽

10.1139/o71-049 ◽

1971 ◽

Vol 49 (3) ◽

pp. 332-336 ◽

Cited By ~ 42

Author(s):

I. G. Walker

Keyword(s):

Mammalian Cells ◽

Unit Length ◽

Cross Linking ◽

Mustard Gas ◽

Dna Molecule ◽

Cross Links ◽

The Cross

When mustard gas reacts with DNA one of the products consists of two guanines linked by a mustard molecule (GMG). This compound can arise from a pair of guanines lying in opposite strands of the DNA molecule and in this form is the basis of the cross-linking effect of mustard gas on the DNA molecule. The present study shows that GMG arises also in significant amounts from the reaction of two guanines that lie in the same strand. Using DNA isolated from mustard gas treated mammalian cells or alkylated in vitro, the number of GMG's per unit length of DNA was determined. The extent of renaturability which measures the degree of cross-linking was also determined. The number of GMG's exceeded the number of cross-links. When alkylated DNA was separated into a renaturable (cross-linked) fraction and one that contained single strands, analysis showed that both fractions contained GMG.

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Vulcanization of Crepe Rubber by Sulfur Monochloride. I. The Gelation Method

Rubber Chemistry and Technology ◽

10.5254/1.3542785 ◽

1955 ◽

Vol 28 (1) ◽

pp. 278-287 ◽

Cited By ~ 1

Author(s):

J. Glazer ◽

J. H. Schulman

Keyword(s):

Room Temperature ◽

Bond Formation ◽

Clear Cut ◽

Sulfur Monochloride ◽

Sulfur Vulcanization ◽

Speed Up ◽

Weak Gel ◽

Kinetics Of ◽

Vulcanization Process ◽

Kinetic Features

Abstract When a dispersion of rubber (4 per cent) in benzene is treated with sulfur monochloride (1 per cent) at room temperature, the solution becomes opaque and gelation occurs in a few minutes. With a more dilute dispersion of rubber (1 per cent), Meyer and Mark obtained a weak gel, which could be broken up by stirring to give, after one hour, a pale yellow precipitate, corresponding to the formula C10H16SCl2. By analogy with the reaction of ethylene and sulfur monochloride, these workers proposed the following reaction process: (see PDF for diagram) The so-called cold-vulcanization process, which is essentially the above reaction, thus appears to correspond to the cross-linking of adjacent isoprene units by means of thioether-bond formation. This result contrasts with the hot sulfur vulcanization process, where the reaction does not involve the sulfurization of any appreciable number of olefinic groups. The mechanism of the cold vulcanization process is unknown. However, it is known that certain commercial sulfur vulcanization accelerators speed up the above gelation process to a remarkable extent. The present work describes an attempt to investigate the kinetics of the reaction between rubber and sulfur monochloride, with the eventual view of establishing the mechanism of the process. In general, two main methods have been developed for assessing reaction velocities. They are the dilatometric method and a more arbitrary time-of-gelation method. While the former method is of importance in studying the more detailed quantitative features of the reaction, the latter method is of help as a powerful auxiliary. Although it is not yet possible to propose a clear-cut mechanism for the vulcanization process, certain kinetic features have been established, and indications of the most fruitful lines of attack are presented.

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