Preparation, characterization, and property testing of condensation‐type silicone/montmorillonite nanocomposites

Abstract

Nanocomposites (NCs) of silicone rubber and organically modified montmorillonite (OMMT) nanoparticles were prepared and characterized. It was shown that OMMT loadings of 2 and 3.5 parts per hundred resin/filler per weight (phr) produced exfoliation or delamination hybrids, whereas at a concentration of 5 phr, the filler seemed to retain its original crystallographic morphology, and the system shifted to an ordinary reinforced elastomer. Fourier transform infrared analysis, differential scanning calorimetry, and thermogravimetric analysis testing were performed for characterization and showed no effect of the nanofiller on the structural parameters of the composites, with the exception of a reduction in the crystallinity. Dynamic mechanical analysis revealed an increase in the glass-transition temperature (T g ) at OMMT concentrations of 2 and 3.5 phr, whereas at 5 phr, T g dropped again. Finally, mechanical testing showed an improvement in the tensile strength and stiffness, whereas improved solvent resistance was recorded by swelling experiments in toluene. This experimental study allowed us to explore the range where the OMMT filler produced NCs with silicone elastomers and, furthermore, showed that the incorporation of OMMT into silicone rubber did not introduce any chemical changes but increased the density of crosslinks; this led to a loss of crystallinity, an increase in T g , and a significant improvement in the tensile properties.

Preparation and characterization of high performance exfoliated montmorillonite/silicone rubber nanocomposites with enhanced mechanical properties

“…A similar observation was also reported regarding the effect of organic modified clays on the vulcanization process of clay/SR nanocomposites but with a different curing system. Voulomenou and Tarantili [ ] claimed that there was a possible interaction between the curing agent and the organic moiety on the organoclay surface instead of a interaction between the curing agent and the rubber chains, which resulted in an increase in the vulcanization time. However, this phenomenon was not seen when untreated clay (Cloisite Na + ) was used in the rubber.…”

“…More recently, research has begun to investigate a new filler system for silicone rubber due to the high price of silica and also the occurrence of silicosis condition among users of silica such as rubber compounders. Therefore, a number of potential fillers for example nanoclay [ ], titanium oxide [ ], and carbon nanotube [ ] have been used in silicone rubber. Among the fillers, nanoclay or montmorillonite (MMT) has received much attention in recent years because it is relatively inexpensive and also noncarcinogenic.…”

The influence of HNTs on the mechanical properties, swelling resistance, and microstructural properties of nanocomposites based on silicone rubber

“…As a result, researchers have investigated various potential llers, including nanoclay [19][20][21][22], titanium oxide [23], and carbon nanotubes [24][25], aiming to increase the mechanical behaviors of SR.…”

Improving heat ageing and thermal properties of silicone rubber using montmorillonite clay

“…The past decade has seen rapid advances in the field of silicone rubber/clay nanocomposite. Montmorillonite (MMT) clay has been widely investigated due to its unique properties that offer high aspect ratio within nanoscale range …”