How the silica determines properties of filled silicone rubber by the formation of filler networking and bound rubber

2021 ◽  
pp. 109024
Author(s):  
Yue Shui ◽  
Lizhao Huang ◽  
Chengsha Wei ◽  
Guangai Sun ◽  
Jie Chen ◽  
...  
Keyword(s):  
Silicone Rubber ◽  
Bound Rubber

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.

The effect of bound rubber on vulcanization kinetics in silica filled silicone rubber

RSC Advances ◽  
2016 ◽  
Vol 6 (103) ◽  
pp. 101470-101476 ◽  
Author(s):  
Lixian Song ◽  
Zhanhong Li ◽  
Liang Chen ◽  
Hanmei Zhou ◽  
Ai Lu ◽  
...  
Keyword(s):  
Silicone Rubber ◽  
Bound Rubber ◽  
Vulcanization Kinetics

Different filler networks mediated by bound rubber show obviously different effects on vulcanization kinetics.

Study on Bound Rubber in Silicone Rubber Filled with Modified Ultrafine Mineral Powder

2000 ◽  
Vol 73 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Jihuai Wu ◽  
Zhen Shen ◽  
Donghong Hu ◽  
Jinling Huang ◽  
Naisheng Chen
Keyword(s):  
Silicone Rubber ◽  
Measurement Method ◽  
Chemical Interaction ◽  
Rubber Matrix ◽  
Main Role ◽  
Mineral Filler ◽  
Organic Base ◽  
Rubber Content ◽  
Bound Rubber ◽  
Mineral Powder

Abstract The bound rubber measurement method was improved by ethylenediamine (NH2-CH2-CH2-NH2) replacing ammonia (NH3) as the basic agent. Using the new method, the influence of organic base on bound rubber content was investigated, the relation between bound rubber content and the mechanical properties of the silicone rubber filled with modified ultrafine mineral powder was studied, and the interaction between silicone rubber matrix and mineral filler was discussed. As a result, it is suggested that chemical interaction plays the main role in the bound rubber of silicone filled with modified ultrafine mineral powder.

Study in Surface Modification of Silica in Silicone Rubber

2012 ◽  
Vol 496 ◽  
pp. 34-37 ◽  
Author(s):  
Jie Sheng Liu ◽  
Dong Lai Li ◽  
Jun Yu ◽  
Zong Wang Zhang
Keyword(s):  
Silicone Rubber ◽  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Silica Filler ◽  
Bound Rubber ◽  
Silane Coupling ◽  
Unmodified Silica ◽  
Ft Ir ◽  
Surface Modified ◽  
Agent Treatment

Silica fillers are well known to improve the mechanical properties of elastomers.Nevertheless, the silica filler particles tend to aggregate and affect the properties of the elastomer. In the present study, the silica filler was modified by silane coupling agent (A-151) in order to improve the dispersion of the filler in silicone rubber. The composites samples added with surface treated silica filler was characterized by FT-IR, bound rubber, and fluorescent microscope with that reinforced by the unmodified filler as a comparison. FT-IR results evidences the successful surface modified by silane coupling agent. Bound rubber contents of the origin silica filler are much lower than that of the silica filler with the silane coupling agent treatment. The modified silica-filled shows a better dispersion than that of the origin silica filler and the agglomeration of filler occurs in the unmodified silica-filler compounds.

Bound rubber and “crepe hardening” in silicone rubber

1977 ◽  
Vol 21 (12) ◽  
pp. 3211-3222 ◽  
Author(s):  
Petr Vondráček ◽  
Miroslav Schätz
Keyword(s):  
Silicone Rubber ◽  
Bound Rubber

Computing cell tractions from particle displacements on silicone rubber substrata

1994 ◽  
Vol 52 ◽  
pp. 162-163
Author(s):  
Tim Oliver ◽  
Akira Ishihara ◽  
Ken Jacobsen ◽  
Micah Dembo
Keyword(s):  
Plane Stress ◽  
Linear Elasticity ◽  
Silicone Rubber ◽  
Mathematical Analysis ◽  
Elastic Recovery ◽  
Video Images ◽  
Cell Traction Forces ◽  
Latex Beads ◽  
Cell Traction ◽  
Better Than

In order to better understand the distribution of cell traction forces generated by rapidly locomoting cells, we have applied a mathematical analysis to our modified silicone rubber traction assay, based on the plane stress Green’s function of linear elasticity. To achieve this, we made crosslinked silicone rubber films into which we incorporated many more latex beads than previously possible (Figs. 1 and 6), using a modified airbrush. These films could be deformed by fish keratocytes, were virtually drift-free, and showed better than a 90% elastic recovery to micromanipulation (data not shown). Video images of cells locomoting on these films were recorded. From a pair of images representing the undisturbed and stressed states of the film, we recorded the cell’s outline and the associated displacements of bead centroids using Image-1 (Fig. 1). Next, using our own software, a mesh of quadrilaterals was plotted (Fig. 2) to represent the cell outline and to superimpose on the outline a traction density distribution. The net displacement of each bead in the film was calculated from centroid data and displayed with the mesh outline (Fig. 3).

Video-microscopic measurement of cell-substratum traction forces generated by locomoting keratocytes

1993 ◽  
Vol 51 ◽  
pp. 188-189
Author(s):  
Tim Oliver ◽  
Michelle Leonard ◽  
Juliet Lee ◽  
Akira Ishihara ◽  
Ken Jacobson
Keyword(s):  
Silicone Rubber ◽  
Molecular Motors ◽  
Video Frame ◽  
Traction Forces ◽  
Cell Traction Forces ◽  
Latex Beads ◽  
Cell Traction ◽  
Local Cell ◽  
Microscopic Measurement ◽  
Kinetics Of

We are using video-enhanced light microscopy to investigate the pattern and magnitude of forces that fish keratocytes exert on flexible silicone rubber substrata. Our goal is a clearer understanding of the way molecular motors acting through the cytoskeleton co-ordinate their efforts into locomotion at cell velocities up to 1 μm/sec. Cell traction forces were previously observed as wrinkles(Fig.l) in strong silicone rubber films by Harris.(l) These forces are now measureable by two independant means.In the first of these assays, weakly crosslinked films are made, into which latex beads have been embedded.(Fig.2) These films report local cell-mediated traction forces as bead displacements in the plane of the film(Fig.3), which recover when the applied force is released. Calibrated flexible glass microneedles are then used to reproduce the translation of individual beads. We estimate the force required to distort these films to be 0.5 mdyne/μm of bead movement. Video-frame analysis of bead trajectories is providing data on the relative localisation, dissipation and kinetics of traction forces.

Performance study of RTV-2 Silicone Rubber Material For Soft Actuator by Experimental and Numerical methods: The Effect of Inflation Pressure and Wall Thickness

2020 ◽  
Vol 17 (1) ◽  
pp. 7524-7532 ◽  
Author(s):  
Deepak D. ◽  
Nitesh Kumar ◽  
Shreyas P. Shetty ◽  
Saurabh Jain ◽  
Manoj Bhat
Keyword(s):  
Numerical Methods ◽  
Wall Thickness ◽  
Silicone Rubber ◽  
Inflation Pressure ◽  
Performance Study ◽  
Rubber Material ◽  
Soft Actuator ◽  
Alternative Materials ◽  
Load Carrying ◽  
Influential Parameters

The expensive nature of currently used materials in the soft robotic industry demands the consideration of alternative materials for fabrication. This work investigates the performance of RTV-2 grade silicone rubber for fabrication of a soft actuator. Initially, a cylindrical actuator is fabricated using this material and its performance is experimentally assessed for different pressures. Further, parametric variations of the effect of wall thickness and inflation pressure are studied by numerical methods. Results show that, both wall thickness and inflation pressure are influential parameters which affect the elongation behaviour of the actuator. Thin (1.5 mm) sectioned actuators produced 76.97% more elongation compared to thick sectioned, but the stress induced is 89.61 % higher. Whereas, the thick sectioned actuator (6 mm) showed a higher load transmitting capability. With change in wall thickness from 1.5 mm to 6 mm, the elongation is reduced by 76.97 %, 38.35 %, 21.05 % and 11.43 % at pressure 100 kPa, 75 kPa, 50 kPa and 25 kPa respectively. The induced stress is also found reduced by 89.61 %, 86.66 %, 84.46 % and 68.68 % at these pressures. The average load carrying capacity of the actuator is found to be directly proportional to its wall thickness and inflation pressure.

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