Modeling processing of silicone rubber: Liquid versus hard silicone rubbers

2010 ◽  
Vol 119 (3) ◽  
pp. 1864-1871 ◽  
Author(s):  
Juan P. Hernández-Ortiz ◽  
Tim A. Osswald
Keyword(s):  
Silicone Rubber ◽  
Silicone Rubbers

scholarly journals DC inline plane test of silicone rubber samples with different filler for high-voltage insulation

2020 ◽  
Vol 18 (2) ◽  
pp. 607
Author(s):  
Nurbahirah Norddin ◽  
Intan Mastura Saadon ◽  
Najwa Kamarudin ◽  
Norain Rahim ◽  
Jeefferie bin Abd Razak
Keyword(s):  
Calcium Carbonate ◽  
High Voltage ◽  
Silicone Rubber ◽  
Hot Press ◽  
Rubber Composites ◽  
High Voltage Insulation ◽  
Internal Mixer ◽  
Silicone Rubbers ◽  
Material Preparation ◽  
Inclined Plane Test

<span>This paper is about preparation of silicone rubber (SiR) samples with different filler for high-voltage insulation purpose. The fillers used were silica from waste glass, calcium carbonate from cockle shell, silica/calcium carbonate and wollastonite. All the fillers were crushed into powder and undergo internal mixer and hot press as a material preparation. It was expected that the combination of filler with silicone rubber would give better result when experiencing ageing process. The direct current (DC) inclined plane test was used to investigate the tracking and erosion on silicone rubber composites. The tracking length was observed between the top and bottom electrode. Comparison would then be made between the silicone rubbers with different fillers based on the result obtained from the experiment.</span>

Network Scission Processes in Peroxide Cured Methylvinyl Silicone Rubber

1967 ◽  
Vol 40 (2) ◽  
pp. 629-634
Author(s):  
D. K. Thomas
Keyword(s):  
Silicone Rubber ◽  
Elevated Temperatures ◽  
Main Chain ◽  
Methyl Groups ◽  
Chain Polymer ◽  
Filled Rubber ◽  
Oxidative Reactions ◽  
Silica Filler ◽  
Silicone Rubbers ◽  
Hydrolysis Of

Abstract In what appeared to be a complex system it transpires that network scission in methylvinyl silicone rubbers at temperatures below 250° C is due largely to hydrolytic reactions in the main chain polymer. At temperatures of 250° C and above there are indications that a significant amount of scission arises from oxidative reactions in the crosslinks, and that this reaction is catalyzed by acidic residues in the rubber. There is no indication that acidic byproducts of the vulcanization reaction catalyze the hydrolysis of siloxane bonds in the polymer. In conventional heat aging tests in which the rubber remains in an unstrained condition the effects of hydrolysis will only be observed if the concentration of water in the system is allowed to rise. Under these circumstances softening will occur because of a shift in the position of equilibrium in the reaction ∼Si—O—Si—O∼ + H2O→∼Si—OH+ HO—Si—O∼ On aging the material in a well ventilated situation the effects of hydrolysis are not seen and the silicone rubber becomes brittle after long exposure at high temperature. This embrittlement must result from additional crosslinking caused by oxidative reactions in the methyl groups of the main chain polymer. When the rubber is used in compression or tension, hydrolytic scission will affect performance, and in applications of this sort it is important to dry the rubber before use and prevent access of moisture to the component during use. With filled rubber the silica filler is a further source of moisture and drying needs to be carried out at elevated temperatures immediately before use. In order to improve the confined heat aging performance of silicone rubber an alternative filler to fine silica is needed which does not have the same affinity for water. It may be, however, that ability to reinforce silicone rubber and affinity for water are inseparable.

scholarly journals Compatibility Study of Silicone Rubber and Mineral Oil

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5899
Author(s):  
Smitha Karambar ◽  
Stefan Tenbohlen
Keyword(s):  
Dielectric Properties ◽  
Moisture Content ◽  
Silicone Rubber ◽  
Mineral Oil ◽  
Acid Number ◽  
Compatibility Study ◽  
Total Acid ◽  
Silicone Rubbers ◽  
Conductive Silicone Rubber ◽  
Solid Insulation

In this study, three types of silicone rubbers, namely, insulative silicone rubber, conductive silicone rubber and silicone rubber with conductive as well as insulative layers are investigated for their compatibility with mineral oil. Mineral oil with different silicone rubber samples is thermally aged at 130 °C for 360 h, 720 h and 1080 h and at 23 °C, 98 °C and 130 °C for 360 h. At the end of each ageing interval, mineral oil and oil-impregnated silicone rubbers are investigated for their dielectric properties. Aged mineral oil samples are investigated for their moisture content, breakdown voltage, colour number, dissolved gases and total acid number, whereas solid insulation samples are investigated for their moisture content. Additionally, pressboard samples in mineral oil and mineral oil without any solid insulation materials are also aged under the same conditions and are investigated for their dielectric properties. From the obtained results, it can be assessed that the presence of carbon particles in conductive silicone rubber negatively impacts the dielectric properties of mineral oil. Among the investigated silicone rubbers, the insulative silicone rubber exhibits good compatibility with mineral oil and a strong potential for being used in mineral oil.

scholarly journals Research on the electric field intensity distribution of high-voltage cable terminal improved by non-linear material

2021 ◽  
Vol 8 ◽  
pp. 23
Author(s):  
Guowei Li ◽  
Yong Wang ◽  
Xuexia Xu
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
High Voltage ◽  
Silicone Rubber ◽  
Internal Field ◽  
Field Distortion ◽  
Non Linear ◽  
Calculation Results ◽  
Linear Material ◽  
Silicone Rubbers

The electric field distortion caused by the high voltage current environment in the cable terminal will greatly increase the failure probability and reduce the operation safety; therefore, it is necessary to ensure the uniform distribution of the electric field in the terminal. This paper briefly introduced the high-voltage cable terminal and non-linear materials. The traditional silicone rubber and the silicone rubber added with nano-SiO2 were prepared. The electrical conductivity of the two silicone rubbers was tested, and the electric field of the cable terminal was simulated. The results demonstrated that the nano-SiO2 improved silicone rubber had a higher non-linear conductivity and was less affected by temperature. The calculation results of the simulation model also showed that the distribution of the internal field strength was more uniform, and the maximum field strength on the reinforced insulation was smaller after the improved silicone rubber was used as the reinforced insulation.

scholarly journals SEMI-ACTIVE DAMPING PERFORMANCE OF IRON PARTICLE FILLED SILICONE RUBBER

2016 ◽  
Vol 3 ◽  
pp. 7-10 ◽  
Author(s):  
Florian Dirisamer ◽  
Umut Cakmak ◽  
Edmund Marth ◽  
Zoltan Major
Keyword(s):  
Magnetic Field ◽  
Silicone Rubber ◽  
Field Effect ◽  
Iron Particle ◽  
Active Damping ◽  
Damping Coefficient ◽  
Silicone Elastomers ◽  
Silicone Rubbers

The aim of this work was to design, produce and evaluate a demonstrator to visualize the magneto-induced damping behaviour of materials. In contrast to standard materials, the damping coefficient of iron particle filled silicone rubbers can be controlled by a semi-active magnetic field. This field effect should be characterized in order to evaluate the suitability of these magnetorheological silicone elastomers for the use in different configurations and applications.

Solution and Diffusion in Silicone Rubber. II. Influence of Fillers

1963 ◽  
Vol 36 (3) ◽  
pp. 651-659 ◽  
Author(s):  
R. M. Barrer ◽  
J. A. Barrie ◽  
N. K. Raman
Keyword(s):  
Silicone Rubber ◽  
Porous Silica ◽  
Reference Models ◽  
Silica Filler ◽  
High Area ◽  
Silicone Rubbers ◽  
And Diffusion

Abstract An investigation has been made of the effect of a high area silica filler upon the solubility and diffusion of some C4 and C5 paraffins in silicone rubbers. The membranes studied contained by weight 0, 10, 20, 30 and 40 parts of filler per 100 parts of polymer. The solubilities have been discussed in terms of two reference models: the first in which silica and rubber phases act independently as sorbents; and the second in which the filler is regarded as completely wetted by polymer and is thus a non-sorbent. Diffusion and permeation have also been considered in terms of the models, assuming with the first model an immobile sorbed layer on the porous silica. It has been found that, although some aspects of the behavior can be explained, the results are not fully in agreement with either model, and that the behavior of the heterogenous membrane is complex.

scholarly journals Fluorosilicone as an Omnimold for Microreplication

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 406 ◽  
Author(s):  
Teng Zhang ◽  
Xiaokui Yue ◽  
Dan Sameoto
Keyword(s):  
Silicone Rubber ◽  
Soft Lithography ◽  
Mold Material ◽  
Material Compatibility ◽  
Thermosetting Polymers ◽  
Molded Parts ◽  
New Material ◽  
Multiple Materials ◽  
Silicone Rubbers ◽  
Micro Structures

Soft lithography and replica molding have been an integral part of polymer basic microfabrication for over 20 years. The use of silicone rubber materials as either molds or directly molded parts are well described in the literature and have provided researchers with an easily accessible technique to reproduce complex micro and nanostructures with minimal costs and technical challenges. Yet, for many applications, the use of standard silicones may not necessarily be the best choice, either as a mold material or as a replicated surface. For those instances where a mold is required that is high temperature tolerant, flexible, durable and capable of being used as a mold for multiple materials including silicone rubber, the most commonly used silicone rubber, Sylgard-184, has substantial deficiencies. In this work, we introduce a new material, Fluorosilicone that has not been described in the microfabrication field in detail and determine it is capable of reproducing micro structures via soft lithography techniques and being used as a mold for thermoplastic and thermosetting polymers, including silicone rubbers. Material compatibility, appropriate processing conditions for quality replicas and demonstration of extremely fast production of silicone microstructures are reported.

The Science and Technology of Silicone Rubber

1962 ◽  
Vol 35 (5) ◽  
pp. 1222-1275 ◽  
Author(s):  
F. M. Lewis
Keyword(s):  
Silicone Rubber ◽  
The United States ◽  
Inorganic Materials ◽  
Silicon Compounds ◽  
Corning Glass ◽  
Synthetic Materials ◽  
Silicon Chemistry ◽  
Important Position ◽  
Silicone Rubbers ◽  
Silicon Oxygen

Abstract This is a review of silicone rubber and challenging it is since the silicones, a relatively new group of completely synthetic materials, are growing very rapidly even when viewed against today's rapidly advancing technology. The silicones bring together something of the properties of inorganic materials with their silicon-oxygen-silicon polymeric backbones combined with a sheath of organic groups, and the properties which result have won for the silicones an important position in our modern array of new materials. By silicones we mean structures which contain silicon-oxygen polymeric backbones with organic groups attached to the silicon. The name arose when Professor F. S. Kipping and thers in the early 1900's began to work with these materials which they thought at first to be analogous to the organic ketones. For this reason they called them “silicoketones” or “silicones” for short. These materials are not at all, however, related to the organic compounds from which they derive their name for they do not contain any silicon double bonds. Instead the polymers are linked together in giant networks of linear and crosslinked polymers by single bonded silicon-oxygen-silicon bonds. Although the silicones have only recently become important they had a relatively early beginning. It was approximately one hundred years ago, in the same year that Kekule proposed the cyclic structure for benzene, that Friedel and Crafts made the first material which could be classified as a silicone. In the intervening years Professor F. S. Kipping published a monumental series of papers on the chemistry of the silicone intermediates up through the year 1937. However, Professor Kipping was mostly interested in the chemistry of the small molecules and placed very little emphasis on the high molecular weight polymers which were to become so important later on. There was a stirring of interest in the industrial potentials for silicones in the 1930's. Dr. Winton Patnode initiated work at General Electric on silicon compounds containing organic groups as did Dr. J. Franklin Hyde at Corning Glass. Meanwhile, in Russia, B. N. Dolgov and K. A. Andrianov were also working in the field of organo-silicon chemistry. In the early 1940's these efforts finally lead to the blossoming of the commercially important silicones. The Direct Process was discovered by Dr. E. G. Rochow and this important process coupled with other basic rubber technology formed the basis for commercial silicone rubber. Since that time the technology has advanced very rapidly and although prior to 1940 there were virtually no patents on silicones and mostly Kipping's papers from the academic point, there are now approximately 10,000 publications throughout the world including U.S. and foreign patents. Activity has expanded at such a rate that the majority of this literature has been generated in the last few years. The scope of the silicone industry is indicated to some extent by the products as shown in Figure 1. Each of the types of products shown here include many individual products so that there are many hundreds of actual products manufactured and sold. The total business at this time in the United States represents approximately $75 million and silicone rubbers account for a substantial fraction of this total.

Investigation of Effect of Additives on Adhesive Properties of Silicone Rubbers Sealant

2009 ◽  
Vol 417-418 ◽  
pp. 437-440
Author(s):  
Jie Sheng Liu ◽  
Shao Peng Wu ◽  
Yi Xuan Mi
Keyword(s):  
Adhesion Strength ◽  
Silicone Rubber ◽  
Coupling Agent ◽  
Adhesion Property ◽  
Coupling Agents ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
Effect Of Additives ◽  
Single Coupling ◽  
Silicone Rubbers

Additives are always added into silicone rubber to improve properties. As a sealant, it is well known that the adhesion property is a key aspect of the sealant system. The effect of additives on the adhesion properties of silicone rubber sealant are discussed in this study. The results showed that the adhesive properties of samples with single coupling agent are lower than that with multiple coupling agents. The adhesive properties of sample first increase with increasing amount of coupling agent and then decrease linearly. The adhesion strength of SR sealant decreased with the amount of the plasticizer and filler added into the silicone rubber has little influence on the adhesion strength of silicone rubber.

Silicone Rubber, Its Development and Technological Progress

1988 ◽  
Vol 61 (3) ◽  
pp. 470-502 ◽  
Author(s):  
Keith E. Polmanteer
Keyword(s):  
Silicone Rubber ◽  
Technological Progress ◽  
Main Chain ◽  
Backbone Flexibility ◽  
Commercial Development ◽  
Silicone Polymers ◽  
Chronological Sequence ◽  
Group Rotation ◽  
Molecular Forces ◽  
Silicone Rubbers

Abstract This paper has described silicone rubber, its first commercial development in 1944, and its technological progress since then. Pioneering research on silicon opened the door to the development of silicone polymers and silicone rubber. The substitution of two methyl groups on silicon was present in the first examples of silicone rubber and still is the predominant organic group in commercial silicone rubber today. Silicone rubbers have filled a need in the marketplace because of their combination of unusual properties not found in other rubbers. The alternating inorganic main-chain atoms of silicon and oxygen, and the two pendant organic groups, primarily methyl, provide strong chain bonds, backbone flexibility, ease of side-group rotation, and low “inter” and “intra” molecular forces. This molecular makeup and properties thereof are primarily responsible for the observed performance of silicone rubbers. Many significant advances in silicone rubber have been discussed in chronological sequence to trace its history from 1944 to 1987.

Sign in / Sign up

Export Citation Format

Share Document