Abstract
High speed friction grinding has been used to grind plant and food substances in water but never been explored for grinding of thermoplastics like polylactic acid (PLA), low and high density polyethylene and polypropylene. Such grinding was investigated in this work and was made possible by using 0.5% guar gum solution instead of just water because increasing the viscosity of water reduced their settling and the speed of passing through the grinder. Tensile, flexural, and impact strengths of the plastics were studied and higher grinding efficiency of PLA could be explained by its low elongation-at-break compared to low density polyethylene, high density polyethylene, and polypropylene. The microplastics (2000–45 μm) were studied for mass and particle size distributions and by scanning electron microscopy, 13C CP/MAS NMR, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. In addition, viscosity of guar gum and contact angles was measured. This new technology can produce finely ground microplastics (710–45 μm) for a variety of applications.
| Original language | English |
|---|---|
| Article number | 50797 |
| Journal | Journal of Applied Polymer Science |
| Volume | 138 |
| Issue number | 32 |
| DOIs | |
| State | Published - Aug 20 2021 |
Funding
This work was funded by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract DE-AC05-00OR22725. We thank the Center for Renewable Carbon (CRC), Fibers and Composites Manufacturing Facility (FCMF) at UTK, Department of Food Science at UTK, Joint Institute for Advanced Materials (JIAM) at UTK and Material Sciences and Technology Division (MTSD), Joint Institute of Biological Sciences (JIBS) at ORNL for providing the facilities that made this work possible. We thank Dr. Philipus Pangloli and Dr. Tao Wu at UTK for use of contact angle instrument, Dr. John Dunlap at JIAM-UTK for use of the SEM instrument, Dr. Siqun Wang at CRC-UTK for use of the friction grinding machine, Sam Williams Jr. at ORNL for CNC router cutting, Ashley Clark at ORNL for microscopy sample preparation and Luna Liang at UTK for recording the video. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States 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 United States Government purposes. The Department of Energy 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). The views and opinions of the authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Movie link: https://data.mendeley.com/datasets/xtnhs8f5zy/1.
| Funders | Funder number |
|---|---|
| Center for Renewable Carbon | |
| DOE Public Access Plan | |
| Fibers and Composites Manufacturing Facility | |
| Joint Institute of Biological Sciences | |
| United States Government | |
| U.S. Department of Energy | DE-AC05-00OR22725 |
| Oak Ridge National Laboratory | |
| University of Tennessee, Knoxville |
Keywords
- galactomannan
- grinding
- guar gum
- milling
- polyethylene
- polylactic acid
- polypropylene
- recycling
- thermoplastics
