Effects of Time and Temperature on the Reaction of Tespt Silane Coupling Agent During Mixing with Silica Filler and Tire Rubber

2002 ◽  
Vol 75 (2) ◽  
pp. 187-198 ◽  
Author(s):  
L. A. E. M. Reuvekamp ◽  
J. W. ten Brinke ◽  
P. J. van Swaaij ◽  
J. W. M. Noordermeer
Keyword(s):  
Coupling Agent ◽  
Mixing Time ◽  
Coupling Agents ◽  
Mixing Conditions ◽  
Rubber Compounds ◽  
Silica Filler ◽  
Silane Coupling ◽  
Sufficient Degree ◽  
Degree Of Coupling ◽  
Sulfur Donor

Abstract The addition of a coupling agent to silica-rubber compounds enhances the filler-matrix compatibility. Under certain mixing conditions the surface of the filler may be only partly activated, which may have an adverse effect on the properties in the final product. Some coupling agents may also act as sulfur donor. The dump temperature employed during mixing and the length of time the compound is exposed to that temperature govern the reaction mechanisms of the coupling agent and determine whether the agent leads to the formation of a silica-rubber bond or acts as a curing agent. A temperature of at least 130 °C is necessary to ensure that the reaction between the coupling agent and the silica proceeds, whereas the coupling agent starts to react with the rubber or to donate sulfur, resulting in scorching, at temperatures above 160 °C. An increase in the 300% modulus and/or G' at 100% strain above 150 °C is an indication of scorching caused by the sulfur in the coupling agent. No scorching is observed when a coupling agent without sulfur is used. Another important parameter is the mixing time. It was observed that the coupling agent must be mixed with the silica for at least 10 minutes at 150 °C to obtain a sufficient degree of coupling.

scholarly journals THE ORIGIN OF MARCHING MODULUS OF SILICA-FILLED TIRE TREAD COMPOUNDS

2019 ◽  
Vol 93 (2) ◽  
pp. 378-394 ◽  
Author(s):  
J. Jin ◽  
J. W. M. Noordermeer ◽  
W. K. Dierkes ◽  
A. Blume
Keyword(s):  
Coupling Agent ◽  
Coupling Reaction ◽  
Coupling Agents ◽  
Key Factors ◽  
Silane Coupling Agents ◽  
Filled Rubber ◽  
Rubber Compounds ◽  
Silane Coupling ◽  
Filler Dispersion ◽  
Distinct Maximum

ABSTRACT Silica-reinforced S-SBR/BR tire tread compounds often show characteristic vulcanization profiles that do not exhibit a distinct maximum in the cure curve nor a plateau profile within acceptable time scales (marching modulus). In such a situation, it is difficult to determine the optimum curing time, and as a consequence, the physical properties of the rubber compounds may vary. Previous studies stated that the curing behavior of silica-filled rubber compounds is related to the degree of filler dispersion, the silanization, and the filler–polymer coupling reaction, as well as to the donation of free sulfur from the silane coupling agent. Such results imply that these are the key factors for minimization of the marching modulus. Various silane coupling agents with different sulfur ranks and functionalities were mixed at varied silanization temperatures. The correlation between these factors and their effect on the marching modulus intensity (MMI) were investigated. The MMI was monitored by measuring the vulcanization rheograms using a rubber process analyzer at small (approximately 7%) and large (approximately 42%) strains to discriminate the effects of filler–filler and filler–polymer interactions on the marching modulus of the silica-filled rubber compounds. Both factors have an intricate influence on the marching modulus, determined by the degree of filler–filler interaction and the coupling agent.

EFFECTS OF SILANE AGENTS AND CURING TEMPERATURES ON VULCANIZATE STRUCTURES

2019 ◽  
Vol 93 (2) ◽  
pp. 414-428 ◽  
Author(s):  
Byungkyu Ahn ◽  
Jong-Yeop Lee ◽  
Donghyuk Kim ◽  
Il Jin Kim ◽  
Sangwook Han ◽  
...  
Keyword(s):  
Coupling Agent ◽  
Crosslink Density ◽  
Silica Surface ◽  
Coupling Reaction ◽  
Rolling Resistance ◽  
Coupling Agents ◽  
Silane Coupling Agents ◽  
Filled Rubber ◽  
Rubber Compounds ◽  
Silane Coupling

ABSTRACT Silane coupling agents are commonly used in silica-filled rubber compounds to hydrophobize the silica surface and improve filler–rubber interaction. The coupling agent bis[3-(triethoxysilyl)propyl]tetrasulfide (TESPT) is the most widely used coupling agent. The tetrasulfide is more reactive than the disulfide in bis[3-(triethoxysilyl)propyl]disulfide (TESPD) due to its low decomposition energy, resulting in more coupling reaction with rubber molecules. Meanwhile, vulcanization temperature affects chemical networks. Polysulfide is vulnerable to heat, so it can be easily broken to form shorter crosslinks. Compounds with TESPD or TESPT were vulcanized at 160 and 180 °C. In addition to the decomposition, the reactivity of the silanes was confirmed from the cure characteristics of the compounds without the curatives. TESPD could also cause a coupling reaction without the curatives such as TESPT known to release free sulfur. By analyzing vulcanizate structures, total crosslink density was separated into chemical crosslink density and filler–rubber networks. Applying TESPT or vulcanizing at 180 °C increased the filler–rubber networks, and the higher vulcanization temperature decreased the chemical crosslink density. By correlating physical properties, effects of the vulcanizate structures on performance of tread compounds were investigated. The filler–rubber interaction was dominant for wet traction and mechanical properties in tensile test. The chemical crosslink density affected rolling resistance.

Novel Coupling Agents for Silica-filled Rubbers with Superior Processing Safety and Improved Hysteresis of the Vulcanizates

2010 ◽  
Vol 38 (1) ◽  
pp. 80-98 ◽  
Author(s):  
M. Gerster ◽  
C. Fagouri ◽  
E. Peregi
Keyword(s):  
Mixing Time ◽  
Cost Savings ◽  
Coupling Agents ◽  
Tire Industry ◽  
Selective Functionalization ◽  
Current State ◽  
Rubber Compounds ◽  
Volatile Organic ◽  
Filled Rubbers ◽  
Ethanol Removal

Abstract One challenge facing green tire technology is to achieve good silica hydrophobation/dispersion within the polymer matrix without a detrimental increase in the rubber compound’s viscosity during compounding. This phenomenon is well known to be induced by premature and unwanted coupling and/or crosslinking of the traditional coupling agents. The current state-of-the-art polysulfides silanes, bis(3-triethoxysilylpropyl)tetrasulfide and to a lesser extent bis(3-triethoxysilylpropyl)disulfide (“Product Application—VP Si 75/VP X 75-S in the Rubber Industry,” Degussa Hüls Report No. PA 723.1E), need to be carefully incorporated with careful temperature control during the rubber compounding to prevent this “scorchy” behavior. This paper will present novel monofunctional silanes which are suited for preparing highly silica-loaded rubber compounds of superior processability, while applying fewer mixing passes, thereby reducing mixing times which can lead to improved productivity and cost savings. Additionally, these safer coupling agents can be processed at higher temperatures which can, again, lead to reduced mixing time and better ethanol removal thereby improving the tire’s physical properties and reducing the volatile organic compounds generated during the tire’s use. The rubber compounds produced using these monofunctional silanes are characterized by lower Mooney viscosity and improved processability. Advantageously, within these novel chemical classes of coupling agents, selective functionalization of the silanes allows production of tailor-made coupling agents which can respond to the specific requirements of the tire industry (Vilgis, T. A. and Heinrich, G., “Die Physic des Autoreifens,” Physikalische Blätter, Vol. 57, 2001, pp. 1–7).

COOPERATIVE EFFECTS OF EPOXIDE FUNCTIONAL GROUPS ON NATURAL RUBBER AND SILANE COUPLING AGENTS ON REINFORCING EFFICIENCY OF SILICA

2014 ◽  
Vol 87 (2) ◽  
pp. 291-310 ◽  
Author(s):  
W. Kaewsakul ◽  
K. Sahakaro ◽  
W. K. Dierkes ◽  
J. W. M. Noordermeer
Keyword(s):  
Natural Rubber ◽  
Functional Groups ◽  
Coupling Agent ◽  
Silica Content ◽  
Coupling Agents ◽  
Silane Coupling Agents ◽  
Cooperative Effects ◽  
Optimal Loading ◽  
Silane Coupling

ABSTRACT Polar functionality attached onto natural rubber has a significant impact on the reinforcing efficiency of silica. Parallel studies involving various levels of epoxidation on natural rubber (ENR) in the absence of bis-(triethoxysilylpropyl) tetrasulfide (TESPT) coupling agent, as well as a combination of ENRs with different loadings of TESPT, provide a better understanding of the various factors that influence the properties of silica-filled ENR compounds. Based on the overall properties, the best possible combination to optimize processability, to reduce filler–filler interaction, and improve vulcanization rate as well as vulcanizate properties, is to use ENR with an epoxide content in the range of 20–30 mol%, together with a small portion of TESPT, that is, 2–4 wt% relative to the silica content. This leads to a reduction of approximately 60–80% of TESPT when compared with the conventional NR compounds, where the optimal loading of TESPT was 9.0 wt% relative to the silica content.

Synthesis of Substrate-bound Seaweed-like Au Nanowires with Amino Silane Coupling Agents

2022 ◽  
Author(s):  
Jialong Yu ◽  
Weiyu Wang ◽  
Shumin Li ◽  
Beibei Yu ◽  
Hongyu Chen ◽  
...  
Keyword(s):  
Coupling Agent ◽  
Active Surface ◽  
Coupling Agents ◽  
Silane Coupling Agents ◽  
One Dimensional ◽  
Amino Silane ◽  
Silane Coupling ◽  
Dimensional Growth ◽  
Au Nanowires

Seaweed-like Au nanowires were synthesized without any nanoparticle seeds. The amino silcane coupling agent 3-aminopropyltriethoxysilane was used to form the active surface on Au substrate to facilitate one dimensional growth....

Pyrolysis-GC/FT-IR Analysis for Silane Coupling Treatment of Glass Fibers

1989 ◽  
Vol 43 (7) ◽  
pp. 1159-1164 ◽  
Author(s):  
Etsuo Nishio ◽  
Nobuo Ikuta ◽  
Tsuneaki Hirashima ◽  
Joichi Koga
Keyword(s):  
Glass Fiber ◽  
Coupling Agent ◽  
Glass Fibers ◽  
Quantitative Information ◽  
Coupling Agents ◽  
Silane Treatment ◽  
Pyrolysis Gas ◽  
Silane Coupling ◽  
Ft Ir ◽  
Preparation Techniques

Pyrolysis gas chromatography coupled with FT-IR (Py-GC/FT-IR) has been applied to the study of silane treatment of E-glass fiber. The glass fiber treated with a silane coupling agent, γ-anilinopropyltrimethoxy-silane (AnPS), is pyrolyzed at 750°C. The pyrolysates are fractionated by GC and analyzed by FT-IR. The main fraction is assigned to the organofunctional group of the coupling agent. Thus, Py-GC/FT-IR enables us to identify the treated coupling agent qualitatively. A mixture of two different coupling agents, AnPS and γ-methacryloxypropyltrimethoxysilane on glass fiber, is separated and characterized from the spectra of fractions resulting from each coupling agent. Py-GC/FT-IR also provides quantitative information regarding the coupling agents on glass fiber. The total amount of the treated coupling agent is estimated according to the calibration curves, which are proportional to the amount of the coupling agent. Moreover, Py-GC/FT-IR enables us to evaluate the fixing ratio of the coupling agent to the total amount through washing the samples with methanol. The fixing ratio falls significantly above treatment concentration. This tendency is consistent with the results from nondestructive sampling preparation techniques in infrared spectroscopy. The above results indicate the usefulness of Py-GC/FT-IR for the evaluation of silane treatment.

Effects of Coupling Agents on the Mechanical Properties of the Calcium Carbonate-Plastic Composite Packaging Materials

2012 ◽  
Vol 200 ◽  
pp. 321-324 ◽  
Author(s):  
Zhao Xia Wang ◽  
De Gao ◽  
Wen Cai Xu
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Great Influence ◽  
Coupling Agents ◽  
Packaging Materials ◽  
Plastic Composite ◽  
Silane Coupling ◽  
The Impact

Mechanical properties of the calcium-plastic composite have a great influence on the containers. The main factors affecting the mechanical properties are the process and material formulations. This paper mainly describes its impact of the addition of coupling agent. Under the usage of analysis of variance on single factor experiment, the mechanical properties of the calcium carbonate-plastic composite with three different coupling agents (silane, titanate and aluminate) were studied in the same test conditions. The results show that: The type and quantity of the coupling agent effect a lot on the mechanical properties of the composite. The silane coupling agent is the most suitable for calcium carbonate-plastic composite packaging materials, and the compatibility of calcium carbonate and polyethylene can be improved. When the silane coupling agent was at a 2.25 wt. % concentration, the tensile and flexural strength were improved obviously, especially the tensile strength increased by 23.24%, but the impact strength improved slightly.

Preparation of Nano-SiO2 Particles Modified by Fluorine Silane Coupling Agent

2014 ◽  
Vol 915-916 ◽  
pp. 709-712
Author(s):  
Xiao Li Wei ◽  
Fa Xing Zhang
Keyword(s):  
Particle Size ◽  
Surface Modification ◽  
Double Bond ◽  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Coupling Agents ◽  
Test Results ◽  
Dsc Analysis ◽  
Dispersion Effect ◽  
Silane Coupling

In this paper nanoSiO2 particles were prepared with the surface grafted fluorine coupling agents and double bond by using surface modification technology. Dispersion effect of nanoSiO2 particles were studied in different solvents ultrasound cavitation. Test results showed in infrared spectroscopy, TEM and laser particle size distribution analyzer that both F8261 and KH-570 have been grafted onto the surface of nanoSiO2 , particle size and distribution of nanoSiO2 after modified by the two coupling agent became smaller and more narrow; Tg-DSC analysis showed that when the amount of of the coupling agent is up to 10%, fluorine coupling agent and double bond grafted onto surface of nanoSiO2 particles reach the saturation.

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