Chemical Interaction between Chlorosulfonated Polyethylene and Silica—Effect of Surface Modifications of Silica

1995 ◽  
Vol 68 (5) ◽  
pp. 815-823 ◽  
Author(s):  
A. Roychoudhury ◽  
P. P. De ◽  
N. Roychoudhury ◽  
A. Vidal
Keyword(s):  
Heat Treatment ◽  
Chemical Interaction ◽  
Sulfonyl Chloride ◽  
Chlorosulfonated Polyethylene ◽  
Silanol Groups ◽  
Precipitated Silica ◽  
Modified Polymer ◽  
Bound Rubber ◽  
Diffuse Reflectance Infrared ◽  
Effect Of Surface

Abstract The surface of precipitated silica was modified by heat treatment (800°C, 4 h) and hexadecanol treatment. Diffuse reflectance infrared Fourier transform spectroscopic (DRIFTS) measurements reveal that the modification of the silica surface reduces the silanol content. Heat treatment causes condensation of the silanol groups forming siloxane linkages, while hexadecanol treatment causes esterification, thereby, shielding the free silanol groups. As a result, the modified silicas exhibit much less interaction with polar molecules (e.g. water, chloroform), compared to the unreacted silica. Bound rubber formation in the chlorosulfonated polyethylene (CSM)/silica system is also adversely affected by the modification of the filler surface. CSM upon heat treatment (180°C, 1 h) loses -SO2Cl groups and the modified polymer lacks in its ability to form bound rubber. Accordingly, it is believed that the rubber-filler interaction occurs between the silanol groups of the silica and sulfonyl chloride groups of CSM.

Chemical Interaction between Carbon Black and Elastomers — Crosslinking of Chlorosulfonated Polyethylene by Carbon Black

1994 ◽  
Vol 67 (4) ◽  
pp. 662-671 ◽  
Author(s):  
A. Roychoudhury ◽  
S. K. De ◽  
P. P. De ◽  
J. A. Ayala ◽  
G. A. Joyce
Keyword(s):  
Carbon Black ◽  
Elevated Temperatures ◽  
Chemical Interaction ◽  
Surface Oxidation ◽  
Rubber Content ◽  
Chlorosulfonated Polyethylene ◽  
Surface Sites ◽  
Bound Rubber ◽  
Thermometric Titration ◽  
Oxidized Carbon

Abstract Surface oxidation of a carbon black leads to an increased elastomer-filler bonding between the chlorosulfonated polyethylene and the carbon black. The increased interaction appears to be related to the increased concentration and reactivity of the oxygen containing sites in the oxidized carbon black, as deduced from the moisture adsorption and thermometric titration results. The bound rubber content is substantially higher for the oxidized carbon black. The reactive surface sites of the carbon black also promote the crosslinking of the elastomer at elevated temperatures.

Effect of Epoxidation Level in Silica Filled Epoxidized Natural Rubber Compound on Cure, Rheological, Mechanical and Dynamic Properties

2014 ◽  
Vol 554 ◽  
pp. 71-75 ◽  
Author(s):  
Afnan Aiman Rohadi ◽  
Abdul Razak Rahmat ◽  
Mazlina Mustafa Kamal
Keyword(s):  
Natural Rubber ◽  
Dynamic Properties ◽  
Small Deformation ◽  
Epoxidized Natural Rubber ◽  
Rubber Content ◽  
Silanol Groups ◽  
Precipitated Silica ◽  
Bound Rubber ◽  
Spectroscopy Studies ◽  
Work Effect

Reinforcement of rubber by precipitated silica is adversely affected due to lack of strong polymer silica bonding. Functionalized polymers interact strongly with surface silanol groups of precipitated silica. In this work, effect of variation of epoxide content in silica filled Epoxidized Natural Rubber (ENR) compound was studied namely ENR 10, 25, 37.5 and 50mol%. Increasing in epoxide level of rubber has contributed to better rubber filler interaction and lead to better mechanical properties. Meanwhile, ENR’s with greater degree of polarity has contributed significantly to higher storage moduli at small deformation and also leads to increase in bound rubber content value. Fourier transform infrared spectroscopy studies showed that the silanol groups in silica interact with ENR through formation of Si-OH bond.

scholarly journals Peculiarities of Chemisorption of Dimethyl Carbonate on Silica Surface

2016 ◽  
Vol 17 (1) ◽  
pp. 88-92
Author(s):  
I.S. Protsak ◽  
E.M. Pakhlov ◽  
V.A. Tertykh
Keyword(s):  
Ir Spectroscopy ◽  
Fumed Silica ◽  
Dimethyl Carbonate ◽  
Silica Surface ◽  
Chemical Interaction ◽  
Spectroscopy Method ◽  
Silanol Groups

This paper presents the results of studies of dimethyl carbonate interaction with sites of the fumed silica surface. The investigations were performed in a vacuum quartz cuvette using IR spectroscopy method. Chemical interaction of dimethyl carbonate with sites of the dehydrated silica surface was shown to occur at temperature of 200 °C and higher, chemisorption processes take place involving both structural silanol groups and siloxane bridges on the surface.

Crosslinking Chlorosulfonated Polyethylenes

1963 ◽  
Vol 36 (4) ◽  
pp. 963-974 ◽  
Author(s):  
J. T. Maynard ◽  
P. R. Johnson
Keyword(s):  
Free Radical ◽  
Sulfonyl Chloride ◽  
High Reactivity ◽  
Good Resistance ◽  
Chlorosulfonated Polyethylene ◽  
Ionic Salt ◽  
Ionic Bonds ◽  
Resistance To Heat ◽  
Curing Systems

Abstract The broadening practical use of chlorosulfonated polyethylene elastomers for applications where good resistance to heat, oil, light, oxygen, and ozone is needed has been accelerated by the development of several chemically distinct curing systems. Optimum use of these saturated elastomers requires a knowledge of the chemistry of these curing reactions and the effect of the resulting crosslink structures on vulcanizate properties. The high reactivity of the sulfonyl chloride crosslinking sites allows wide latitude in choice of curing chemistry, and crosslink type can be controlled to give a preponderance of ionic salt bonds or to give a mixture of covalent and ionic bonds. The role of water, alcohols, sulfur accelerators and free radical stabilizers in the various practical curing systems is discussed. The development of wholly organic curing systems for chlorosulfonated polyethylenes is reviewed. The properties of vulcanizates of chlorosulfonated polyethylenes are also significantly controlled by the base polyethylene, by chlorine content, and by chlorine distribution. The effects of these variables on vulcanizate properties is briefly reviewed.

Fatigue in Engine Design

1953 ◽  
Vol 57 (513) ◽  
pp. 580-584
Author(s):  
F. M. Owner
Keyword(s):  
Crystal Structure ◽  
Heat Treatment ◽  
Cold Work ◽  
Controlled Atmosphere ◽  
The Core ◽  
Test Conditions ◽  
Engine Design ◽  
The Difference ◽  
Cylindrical Test ◽  
Effect Of Surface

The difference in outlook between metallurgist, physicist and designer on the problem of fatigue of metals is due not only to the differences in training and method but also in immediate objective, however closely their ultimate objectives may coincide.Physicists consider fatigue in terms of crystal structure and composition of the constituents of the crystal, noting in passing that certain types of crystal structures are associated with poor fatigue strength. The metallurgist's prime interest lies in the effect of surface finish, heat treatment, the physical condition of the surface, such as degree of cold work, the effect of carburised and nitrided cases having different hardness from the core. Both think in terms of controlled condition tests, with idealised test conditions such as cylindrical test specimens, close control of changes of section, polished surfaces of only a few micro-inches surface roughness, operating in a controlled atmosphere.

Filler—Elastomer Interactions. Part IV. The Effect of the Surface Energies of Fillers on Elastomer Reinforcement

1992 ◽  
Vol 65 (2) ◽  
pp. 329-342 ◽  
Author(s):  
Siegfried Wolff ◽  
Meng-Jiao Wang
Keyword(s):  
Carbon Black ◽  
Small Strain ◽  
Rubber Content ◽  
Specific Component ◽  
Dispersive Component ◽  
Surface Energies ◽  
Precipitated Silica ◽  
Bound Rubber ◽  
High Elongation ◽  
Polymer Interaction

Abstract Carbon black N110 and a precipitated silica, which have comparable surface area and structure, were selected as model fillers to study the effect of filler surface energies on rubber reinforcement. In comparison with carbon black, the surface energies of silica are characterized by a lower dispersive component, γsd, and higher specific component, γssp. It was found that the high γssp of silica leads to strong interaggregate interaction, resulting in higher viscosity of the compounds, higher αƒ, and higher moduli of the vulcanizates at small strain. The higher γsd of carbon black, in contrast, causes strong filler—polymer interaction, which is reflected in a higher bound-rubber content of the compounds and higher moduli of the vulcanizates at high elongation.

Reinforcement of Silicone Rubber by Particulate Silica

1975 ◽  
Vol 48 (4) ◽  
pp. 558-576 ◽  
Author(s):  
B. B. Boonstra ◽  
H. Cochrane ◽  
E. M. Dánnenberg
Keyword(s):  
Silicone Rubber ◽  
Silica Surface ◽  
Specific Interaction ◽  
Interaction Coefficient ◽  
Hydroxyl Groups ◽  
Surface Hydroxyl ◽  
Silanol Groups ◽  
Compression Set ◽  
Surface Hydroxyl Groups ◽  
Bound Rubber

Abstract The interaction between fumed silica and silicone elastomer after various treatments of the silica surface has been investigated. The effect of the treatments was determined by measuring bound rubber, an interaction coefficient by means of the oscillating disk rheometer, the mechanical properties of the vulcanizates, the morphology of the silica aggregates, and the use of an hydroxyl-terminated silicone rubber. The results indicated that the interaction is much more intensive than in carbon black-hydrocarbon rubber systems. This is demonstrated by much higher bound rubber values (by a factor of 2–3) and a higher interaction coefficient. It is shown that the major effect on this interaction coefficient is the specific interaction by hydrogen bonding, between silica surface silanol groups and the polydimethylsiloxane chain. In this bonding the isolated hydroxyl groups should play the major part. Partial inactivation of these isolated silanol groups leads to improved strength but lower modulus. Maximum inactivation of the surface hydroxyl groups leads to soft compounds with lower tensile strengths and moduli, as well as very low bound rubber. Replacement of surface hydroxyl groups by vinyldimethylsilyl groups did not have the expected activating effect. Apparently the attached vinyldimethylsilyl groups do not form crosslinks with the elastomer chains, so that the overall result of the presence of these groups on the silica surface is a weakening of the interaction with the silicone rubber chains, although to a lesser degree than in the case of trimethylsilyl groups. The interaction between filler surface and polysiloxane can be maximizedby the use of a hydroxyl-terminated elastomer. The terminal groups will react with the silica surface so strongly that the particles act as crosslinks after proper heat treatment and a crosslinked polymer is obtained with a tensile strength of the same level as a peroxide-crosslinked vulcanizate but with higher compression set. At the temperature of the compression set test (175°C) the bonds apparently rearrange so that the permanent deformation is practically 100%. Quantitative data have been presented which prove that breakdown of silica aggregates does occur during mixing in silicone rubber on a two-roll mill.

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