A mussel-inspired mechanism was used to solve the problem of filler aggregation in rubber composites. This research aims to improve carbon black (CB) dispersion in epoxidized natural rubber (ENR) composites through π−π stacking and cation−π interactions by adding dopamine (D). In this study, various aromatic interactions (π−π stacking and cation−π interactions) between the D-functionalized ENR molecules and the surface of the CB were observed by Fourier transform infrared (FTIR) and Raman spectroscopy. Notably, the small and wideangle X-ray scattering (SAXS/WAXS) analyses supported our inference from the rubber processing analysis (RPA) and transmission electron microscopy (TEM) results that the aromatic interactions enhanced the CB dispersion in ENR composites. This phenomenon improved the tensile strength (138%), Young’s modulus (93%), and energy-saving properties (50%). Finally, this research provided an alternative strategy using mussel-inspired material to solve the CB aggregation problem in rubber products, yielding ENR composites with superior performance properties.
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Poly(butadiene-graft-pentafluorostyrene) as a Coupling Agent in Rubber Compounding Presented at the 12th Annual Student Colloquium & Poster Session at the Fall 188th Technical Meeting of the Rubber Division, ACS Cleveland, Ohio U.S.A.
Reinforcing fillers are necessary in rubber compounding to aid in enhancing the mechanical properties of the compound for various applications. Carbon black (CB) is currently the most common reinforcing filler used in tire compounding. Lignin, an amorphous polyphenolic material derived from plants and a by-product of the pulp and paper industry, is also an attractive material that can serve as a dispersant and as a reinforcing filler. This paper evaluates the interactions between styrene-butadiene rubber and reinforcing fillers with an electron-rich π- system, such as lignin and CB, in the presence of a graft copolymer (PB-g-PPFS) of PB and electron-deficient 2,3,4,5,6-pentafluorostyrene (PFS). The interactions are attributed to areneperfluoroarene interactions between the electron-deficient π-system of the polyperfluoroarene grafts and the electron-rich π-system of lignin and/or CB particles. The effects of improved fillerrubber interactions on mechanical properties and dynamic mechanical properties are analyzed. This paper will demonstrate the use of PB-g-PPFS as a coupling agent in rubber compounds to enhance the interaction between the filler, lignin and lignin-carbon black hybrid filler, and the rubber matrix to achieve a reduction in the hysteresis loss and enhanced filler dispersion.
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- Award ID(s):
- 1650460
- PAR ID:
- 10078837
- Date Published:
- Journal Name:
- International Elastomer Conference of ACS
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Coupling agents are intended to promote filler dispersion by providing a bridge between the filler and the rubber phase. This study investigated the ability of a novel physical coupling agent, poly(butadienegraft-pentafluorostyrene) in a mixture with polypentafluorostyrene, to improve rubber-filler interactions and suppress filler-filler networking in carbon-black-reinforced styrene-butadiene rubber (SBR), and thereby decrease hysteresis. The electron-rich aromatic rings of carbon black are involved in areneperfluoroarene interactions with the electron-poor pentafluorostyrene aromatic rings of the coupling agent. The SBR chains in the rubber compound have an affinity for the polybutadiene backbone of the coupling agent. The interactions between carbon black and the coupling agent were analyzed using Raman spectroscopy, transmission electron microscopy, zeta potential measurements, surface area measurements, and scanning electron microscopy. Filler flocculation analysis showed that the coupling agent improves the dispersion and lowers the energy of dissipation. The hysteresis loss, quantified in terms of loss tangent values at 60 C, was reduced by up to 12% due to the coupling agent's promotion of better filler-rubber interactions. The influence of the PPFS graft length was also studied.more » « less
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