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

In this paper, the sol-gel method was used for in-situ synthesis of SiO2 nanoparticles (NPs) on cotton fabrics with tetraethyl orthosilicate (TEOS) in the presence of acid and alkaline indicators. The samples were characterized using by (X-ray diffraction) XRD, (scanning electron Microscopy) SEM, (Inductively coupled plasma) ICP, water drop test and also the flame retardant properties were studied by char yield. The SEM images showed that the nanoparticles are spherical in shape and the acidity or alkalinity of the medium has an effect on the formation of particles. The XRD patterns showed the typical diffraction of amorphous SiO2 (Si-O short-order structure), also ICP analysis showed that by washing the fabrics, the nanoparticles are still present on the fabric, and this indicated the stability of the washing of the fabrics impregnated with the nanoparticles. By in-situ synthesis of SiO2 nanoparticles, the flame retardant properties have been improved significantly and the amount of residual char was increased and samples were observed to be hydrophilic.

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FUNCTIONALIZATION OF EPDM RUBBER TOWARD BETTER SILICA DISPERSION AND REINFORCEMENT

Rubber Chemistry and Technology ◽

10.5254/rct.18.81564 ◽

2018 ◽

Vol 92 (2) ◽

pp. 219-236 ◽

Cited By ~ 1

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.

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