Abstract
Microcrystalline cellulose (MCC) is a promising bio-based filler for lightweight yet mechanically high-performance eco-polymer composites because of its low density and high biocompatibility. However, intermolecular hydrogen bonding among MCC is stronger than the polymer–filler interactions, which deteriorate the mechanical properties of the composites. Herein, we investigated the effects of functional groups on the mechanical properties of composites by scrutinizing chemically modified microcrystalline methyl cellulose (m-MMC) with three different substitution levels of hydroxyl group to hydroxypropyl (HP) group: no-, low-, and high-level substitution (HP-0, HP-low, and HP-high). The degree of HP substitution of m-MMC was quantitatively measured by CP/MAS NMR analysis. The relatively bulky HP groups interrupted the filler–filler intermolecular interactions and reduced the crystallinity and density of m-MMC, as evident from X-ray diffractometer and pycnometer data, respectively. For scalable production of the composites, the m-MMC were compounded with thermoplastic polyurethane (TPU) by a twin-screw extruder at concentrations between 0.5 and 10 wt%. Despite its low filler concentration, the toughness of m-MMC/TPU composites was remarkably enhanced, up to 28% (229.2 to 294.4 MJ/m3) at 0.5 wt% loading of HP-low, owing to the enhanced polymer–filler interactions. The fundamental understanding on structure–property relationships will provide insights for designing of mechanically robust yet eco-friendly polymer composites. Graphical abstract: [Figure not available: see fulltext.]
| Original language | English |
|---|---|
| Pages (from-to) | 6917-6931 |
| Number of pages | 15 |
| Journal | Cellulose |
| Volume | 30 |
| Issue number | 11 |
| DOIs | |
| State | Published - Jul 2023 |
Funding
Funding is provided by National Research Foundation of the Republic of Korea (Grant No. NRF-2017H1D8A1032288), Ministry of Trade, Industry and Energy of the Republic of Korea (Grant Nos. 20011362, P0017303), U.S. Department of Energy (Grant No. DE-AC05-00OR22725). This work was supported by the Technology Innovation Program (No. 20011362, Development of Eco-friendly Solid Insulation Materials and Core Parts for High Voltage Switchgear) funded by the Ministry of Trade, Industry & Energy (MOTIE) and the Korea Evaluation Institute of Industrial Technology (KEIT) of the Republic of Korea, by the X-mind Corps program of the National Research Foundation (NRF) of the republic of Korea funded by the Ministry of Science, ICT (NRF-2017H1D8A1032288), and by the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea under the Fostering Global Talents for Innovative Growth Program (No. P0017303) supervised by the Korea Institute for Advancement of Technology (KIAT) in part by the NRF. Oak Ridge National Laboratory is managed by UT-Battelle, LLC under Contract DE-AC05-00OR22725 with the U.S. Department of Energy (DOE). 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.
Keywords
- Composites
- Mechanical properties
- Microcrystalline cellulose
- Structure–property relationships
- Thermoplastic polyurethane