Silica-Based Composites with Enhanced Rheological Properties Thanks to a Nanosized Graphite Functionalized with Serinol Pyrrole

Gea Prioglio,Stefano Pandini,Silvia Agnelli,Maurizio Galimberti

doi:10.3390/app112311410

Gea Prioglio, Stefano Pandini + Show 2 more

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https://doi.org/10.3390/app112311410

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Journal: Applied sciences	Publication Date: Dec 2, 2021
Citations: 1	License type: CC BY 4.0

Affiliation: Politecnico di Milano, University of Brescia

Abstract

Silica-based rubber composites have tremendous importance, as they allow the reduction in hysteresis in demanding dynamic-mechanical applications such as tire compounds and hence have a lower environmental impact. However, they also present drawbacks such as poor rheological behavior. In this work, an innovative silica-based hybrid filler system was developed, obtaining a rubber composite with an improved set of properties. A nanosized high surface area graphite (HSAG) was functionalized with 2-(2,5-dimethyl-1H-pyrrol-1-yl)propane-1,3-diol, serinol pyrrole (SP), through a simple process characterized by a high carbon efficiency. The HSAG-SP adduct, with about nine parts of SP per hundred parts of carbon filler, was used to form a hybrid filler system with silica. An elastomeric composite, with poly(styrene-co-butadiene) from anionic polymerization and poly(1,4-cis-isoprene) from Hevea brasiliensis was prepared with 50 parts of silica, which was replaced in a minor amount (15%) by either pristine HSAG or HSAG-SP. The best set of composite properties was obtained with HSAG-SP: the same dynamic rigidity and hysteresis and tensile properties of the silica-based material and appreciably better rheological properties, particularly in terms of flowability. This work paves the way for a new generation of silica-based composites, with improved properties, based on a hybrid filler system with a nanosized edge functionalized graphite.

Highlights

Toward the end of the last century, silica revolutionized the field of elastomer composites, becoming the preferred reinforcing filler for large scale highly demanding dynamicmechanical applications such as tire compounds
Large Discussion agglomerates silica are visible in the Silica/high surface area graphite (HSAG) compound (Figure 8a), Theeven results reported abovecan show that HSAG-serinol pyrrole (SP), used in place of a minor amount whereas silica dispersions be observed in the silica/HSAG-SP
This is behavior related to the interaction silica and withdynamic the graphene layers properties as the composite with as the of only with slightly filler networking edge functionalized with SP

Summary

Introduction

Toward the end of the last century, silica revolutionized the field of elastomer composites, becoming the preferred reinforcing filler for large scale highly demanding dynamicmechanical applications such as tire compounds. The technology based on precipitated silica is developed at the industrial scale and has been used to produce billion of tires. It would be highly desirable to substitute or at least to partially replace silica with an alternative filler, maintaining the same composite dynamic mechanical properties and eliminating or at least reducing the mentioned drawbacks. The alternative filler should have functional groups able to establish a chemical bond with the elastomer chains and/or to create a hybrid network with silica. A lower acidity, with respect to silica, is desirable to have more efficient vulcanization

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