FUNCTIONALIZATION OF EPDM RUBBER TOWARD BETTER SILICA DISPERSION AND REINFORCEMENT

2018 ◽  
Vol 92 (2) ◽  
pp. 219-236 ◽  
Author(s):  
Naresh D. Bansod ◽  
Bharat P. Kapgate ◽  
Pradip K. Maji ◽  
Anasuya Bandyopadhyay ◽  
Chayan Das
Keyword(s):  
Maleic Anhydride ◽  
Sol Gel ◽  
Silica Content ◽  
Rubber Matrix ◽  
Epdm Rubber ◽  
In Situ Silica ◽  
Grafted Epdm ◽  
Composite Properties ◽  
Rubber Filler

ABSTRACT Functionalization of non-polar ethylene propylene diene monomer (EPDM) rubber by melt grafting of maleic anhydride (MA) and in situ incorporation of sol–gel derived silica in the MA grafted EPDM has been done to prepare EPDM/silica composites to use dual benefits of both the approaches, which results in adequate rubber–filler compatibility, good filler dispersion, and enhanced composite properties. Controlled growth of silica up to 25 parts per hundred rubber (phr) is carried out with the solution sol–gel process using tetraethoxysilane (TEOS) as a silica precursor. Mechanical and dynamical properties of the composites are found to improve consistently as silica content increases. Furthermore, treatment of maleic anhydride grafted EPDM by γ-aminopropyltrimethoxysilane (γ-APS) results in remarkable improvement in composite properties even at the same silica content. This is attributed to the generation of uniformly dispersed spherically shaped nanosilica throughout the rubber matrix as observed in a transmission electron microscopic (TEM) study. This contributes to enhanced crosslinking density and improved rubber–filler interaction. In fact, the reinforcement effect brought by in situ silica relative to unmodified in situ silica/EPDM composites is found to be much higher than that reported in recent work on EPDM/in situ silica composites even with higher silica loading. The mechanical, rheological, and dynamic mechanical behaviors of all the composites are evaluated and compared in detail.

Controlled growth of in situ silica in a NR/CR blend by a solution sol–gel method and the studies of its composite properties

RSC Advances ◽  
2015 ◽  
Vol 5 (66) ◽  
pp. 53559-53568 ◽  
Author(s):  
Naresh D. Bansod ◽  
Bharat P. Kapgate ◽  
Chayan Das ◽  
Debdipta Basu ◽  
Subhas Chandra Debnath ◽  
...  
Keyword(s):  
Sol Gel ◽  
Controlled Growth ◽  
Gel Method ◽  
Sol Gel Method ◽  
In Situ Silica ◽  
Composite Properties

Controlled loading of in situ silica in NR/CR blend by solution sol–gel method for enhancing the reinforcement.

In Situ Filling of Silica onto “Green” Natural Rubber by the Sol—Gel Process

2001 ◽  
Vol 74 (1) ◽  
pp. 16-27 ◽  
Author(s):  
S. Kohjiya ◽  
K. Murakami ◽  
S. Iio ◽  
T. Tanahashi ◽  
Y. Ikeda
Keyword(s):  
Natural Rubber ◽  
Silica Surface ◽  
Sol Gel ◽  
Renewable Resource ◽  
Crosslinking Density ◽  
Silica Particles ◽  
Rubber Matrix ◽  
In Situ Silica ◽  
Silica Composite

Abstract The sol—gel reaction of tetraethoxysilane produced the fine and well-dispersed in situ silica particles in the “green” natural rubber (NR) matrix before curing. This new method was developed for a NR/silica composite material, and a good reinforcement effect of in situ silica was observed on the NR vulcanizate. The method is expected to be an industrially practical technique. The in situ silica did not much inhibit the accelerated sulfur curing. Thus, it is estimated that the concentration of silanol groups on the in situ silica surface was smaller than those on the conventional silica surface. The silica—silica interaction of in situ silica seems to be weaker to result in better dispersion in the rubber matrix compared with the conventional silica. Atomic force microscopy suggested that the wettability of NR onto in situ silica was higher than that onto conventional silica. The hardness, modulus at 50% elongation and the storage modulus at room temperature of in situ silica-filled NR vulcanizate were smaller than those of conventional silica-filled NR vulcanizate, although the crosslinking density of the former was larger than that of the latter and their silica contents were comparable. These unique characteristics of in situ silica-filled vulcanizate seem to be ascribed to the fine and well-dispersed in situ silica particles in the NR matrix. These observations suggest that NR (a renewable resource)/in situ silica composite has much potential as an ecologically “green” material in the rubber industry.

Enhancing Dispersion of Silica Nanoparticles with Ammonium Laurate Surfactant for Natural Rubber Latex Composites

2019 ◽  
Vol 821 ◽  
pp. 74-80
Author(s):  
Wichudaporn Seangyen ◽  
Paweena Prapainainar ◽  
Pongdhorn Sae-Oui ◽  
Surapich Loykulnant ◽  
Peerapan Dittanet
Keyword(s):  
Natural Rubber ◽  
Silica Nanoparticles ◽  
Sol Gel ◽  
Natural Rubber Latex ◽  
Silica Content ◽  
Rubber Matrix ◽  
Rubber Composites ◽  
Rubber Latex ◽  
Beam Radiation

In-situ silica nanoparticles with ammonium laurate surfactant in natural rubber latex composites were characterized to describe the reinforcement mechanism in enhanced mechanical properties. In-situ sol-gel method was introduced to generate silica nanoparticles in natural rubber latex using a mole ratio of water-to-TEOS of 28.9 stirring at room temperature for 24 hours. The addition and effect of adding ammonium laurate surfactant for enhancing dispersion and compatibility between silica nanoparticles and rubber matrix was also studied. The natural rubber latex was then vulcanized by electron beam radiation at 200 kGy. The silica content in rubber composites made in-situ, was analyzed by TGA, showed an increase from 3.08 phr to 8.92 phr, corresponding to addition of TEOS amounts of 10 phr to 30 phr, respectively. The dispersion of silica nanoparticles in rubber matrix with ammonium laurate surfactant was improved and exhibited less aggregation than rubber composites absent of ammonium laurate surfactant as evidenced by SEM-EDX. The increase of silica content in rubber composites exhibited lower swelling ratio and higher crosslink density when compared with neat natural rubber. Also, the modulus at 100% and 300% strain also increased with increasing silica nanoparticles incorporation in contrast to tensile strength.

In Situ Silica Filled Styrene Grafted Natural Rubber by the Sol-Gel Process

2010 ◽  
Vol 93-94 ◽  
pp. 525-528 ◽  
Author(s):  
Torpong Sittiphan ◽  
Pattarapan Prasassarakich ◽  
Sirilux Poompradub
Keyword(s):  
Natural Rubber ◽  
Reaction Temperature ◽  
Sol Gel ◽  
Cumene Hydroperoxide ◽  
Silica Content ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
In Situ Silica ◽  
Tetraethylene Pentamine

In situ silica filling of styrene grafted natural rubber (ST-g-NR) was carried out by using sol-gel reaction of tetraethoxysilane (TEOS). The effects of concentration of catalyst and reaction temperature on the in situ silica content were investigated. ST-g-NR was synthesized via an emulsion polymerization using cumene hydroperoxide (CHPO) and tetraethylene pentamine (TEPA) as initiators. The synthesized ST-g-NR was characterized by a Fourier Transform Infrared Spectroscopy (FTIR) and Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR). The content of in situ silica generated in ST-g-NR matrix was determined by Thermogravimetry Analysis (TGA). In situ silica up to 50 parts per hundred rubbers by weight (phr) was successfully filled in the ST-g-NR matrix. The silica content increased with the increase of n-hexylamine concentration. However, the effect of reaction temperature was insignificant to silica content.

Reinforcing efficiency and compatibilizing effect of sol–gel derived in situ silica for natural rubber/chloroprene rubber blends

RSC Advances ◽  
2014 ◽  
Vol 4 (102) ◽  
pp. 58816-58825 ◽  
Author(s):  
Bharat P. Kapgate ◽  
Chayan Das
Keyword(s):  
Natural Rubber ◽  
Sol Gel ◽  
Rubber Blends ◽  
In Situ Silica ◽  
Chloroprene Rubber ◽  
Compatibilizing Effect

The strong CR/in situ silica interaction causes filler accumulation at the interphase and enhances the compatibility and reinforcement in the NR/CR blend.

Polyamide-6,6/in situ silica hybrid nanocomposites by sol–gel technique: synthesis, characterization and properties

Polymer ◽  
2005 ◽  
Vol 46 (10) ◽  
pp. 3343-3354 ◽  
Author(s):  
Rajatendu Sengupta ◽  
Abhijit Bandyopadhyay ◽  
Sunil Sabharwal ◽  
Tapan K. Chaki ◽  
Anil K. Bhowmick
Keyword(s):  
Sol Gel ◽  
Hybrid Nanocomposites ◽  
In Situ Silica ◽  
Gel Technique ◽  
Silica Hybrid

In situ silica reinforcement of natural rubber by sol–gel process via rubber solution

2009 ◽  
Vol 52 (2) ◽  
pp. 219-227 ◽  
Author(s):  
Benjawan Chaichua ◽  
Pattarapan Prasassarakich ◽  
Sirilux Poompradub
Keyword(s):  
Natural Rubber ◽  
Sol Gel ◽  
In Situ Silica ◽  
Sol Gel Process

Silica and Silane Coupling Agent for in Situ Reinforcement of Acrylonitrile-Butadiene Rubber

1999 ◽  
Vol 72 (1) ◽  
pp. 119-129 ◽  
Author(s):  
K. Murakami ◽  
S. Osanai ◽  
M. Shigekuni ◽  
S. Iio ◽  
H. Tanahashi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Silica Particles ◽  
Butadiene Rubber ◽  
Acrylonitrile Butadiene Rubber ◽  
In Situ Silica ◽  
Transmission Electron ◽  
Dispersion Agent ◽  
The Relationship

Abstract In situ silica reinforcement for the acrylonitrile-butadiene rubber (NBR) vulcanizates, which were premixed with a conventional silica (VN-3) and γ-mercaptopropyltrimethoxysilane (γ-MPS), was achieved by the sol-gel reaction of tetraethoxysilane (TEOS) using ethylenediamine. It was observed that the reinforcement efficiency tended to increase with the increase of mechanically premixed conventional silica. From the observations of transmission electron microscopy and scanning electron microscopy, the simultaneous use of VN-3 and γ-MPS was found to promote the formation of large silica particles and clusters with a relatively good dispersion by the sol-gel reaction of TEOS in the NBR vulcanizate. The results of hysteresis measurements supported this promotion. It was considered to be due to the surface modification of VN-3 by the sol-gel reaction of TEOS and the presence of γ-MPS which worked as a dispersion agent for silica particles. The relationship between the mechanical properties and the morphology of the in situ silica filled vulcanizates is discussed.

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