Abstract
An ionomeric, leathery thermoplastic with high mechanical strength is prepared by a new thermal processing method from a soft, melt-processable rubber. Compositions made by incorporation of equal-mass lignin, a renewable oligomeric feedstock, in an acrylonitrile-butadiene rubber often yield weak rubbers with large lignin domains (1–2 µm). The addition of zinc chloride (ZnCl2) in such a composition based on sinapyl alcohol-rich lignin during a solvent-free synthesis induces a strong interfacial crosslinking between lignin and rubber phases. This compositional modification results in finely interspersed lignin domains (<100 nm) that essentially reinforce the rubbery matrix with a 10–22 °C rise in the glassy-to-rubbery transition temperature. The ion-modified polymer blends also show improved materials properties, like a 100% increase in ultimate tensile strength and an order of magnitude rise in Young's modulus. Coarse-grained molecular dynamics (MD) simulations verify the morphology and dynamics of the ionomeric material. The computed result also confirms that the ionomers have glassy characteristics.
Original language | English |
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Article number | 1900059 |
Journal | Macromolecular Rapid Communications |
Volume | 40 |
Issue number | 13 |
DOIs | |
State | Published - Jul 2019 |
Funding
This research at Oak Ridge National Laboratory (ORNL), managed by UT Battelle, LLC, for the US Department of Energy (DOE) under contract DE-AC05-00OR22725, was sponsored by the Office of Energy Efficiency and Renewable Energy BioEnergy Technologies Office Program. SAXS (J.K.K.) and electron microscopy (J.C. and N.A.N.) experiments were conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. M.G., C.C.B., and A.K.N. acknowledge the ORNL Laboratory Director R&D Program. The MD simulations (M.G.) were performed at the National Center for Computational Sciences and used resources of the ORNL Oak Ridge Leadership Computing Facility, which is supported by the DOE Office of Science.
Keywords
- ionomeric thermoplastic
- lignin
- melt-rheology
- molecular dynamics simulation
- small-angle X-ray scattering