Abstract
With the growing requirement for lightweight structural materials in automotive, aerospace, and infrastructure applications, multi-material joints made with adhesive have attracted intense research interest. Commercial thermoset adhesives are one-time cures, and difficult to disassemble the bonded components for repair and recycling. Our prior work with a thermoplastic acrylonitrile-butadiene-lignin rubber (ABL) addresses this sustainability/recycling challenge, but the adhesive exhibits deficient joining strength compared to standard thermosets. Here, we modify the ABL matrix by loading particulate fillers to enhance its modulus and toughness. The goal is to manufacture a cure-free thermoplastic adhesive system with a simple dispensing protocol and characteristic ductility combined with a high yield stress for improved shear strength of a bonded joint. Fumed silica (FS) and epoxidized glass spheres (EGS) were used as fillers in the ABL to promote the dispersion of lignin particles that tailored the functionalities and free energy components of the adhesive surface. With optimal loading of FS (5 wt%) and EGS (30 wt%) in the ABL adhesive matrix, the lap-shear strength of the bonded aluminum joint was elevated by 128%, compared to the neat ABL, reaching 21 MPa, which is 90% of the performance of a commercial epoxy-based adhesive. Highlights: A partly renewable filler-toughened thermoplastic adhesive has been developed. This thermoplastic gives nearly equivalent performance of adhesively bonded aluminum joint compared to standard thermosets. Experimental and simulation data help understand the adhesive reinforcing mechanism by the fillers.
| Original language | English |
|---|---|
| Pages (from-to) | 7178-7190 |
| Number of pages | 13 |
| Journal | Polymer Composites |
| Volume | 45 |
| Issue number | 8 |
| DOIs | |
| State | Published - Jun 10 2024 |
Funding
This research is supported by the Sustainable Transportation Program of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office (EERE‐VTO). Amit K. Naskar acknowledges support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences, and Engineering Division [FWP# ERKCK60] for rheology and DMA data analysis of ABL compositions filled with epoxy‐functionalized glass spheres. This manuscript has been authored by UT‐Battelle, LLC, under contract DE‐AC05‐00OR22725 with the U.S. Department of Energy (DOE). The U.S. Government retains, and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid‐up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript or allow others to do so, for US Government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).
| Funders | Funder number |
|---|---|
| EERE‐VTO | |
| U.S. Department of Energy | |
| Office of Science | |
| Basic Energy Sciences | |
| Wind Energy Technologies Office | |
| Division of Materials Sciences and Engineering | DE‐AC05‐00OR22725, ERKCK60 |
Keywords
- adhesion
- joints/joining
- lignin