Effect of isolation method on reinforcing capability of recycled cotton nanomaterials in thermoplastic polymers
Cellulose extracted from recycled pulverized cotton in nanocrystalline cellulose (CNC) and nanofibrillated cellulose (NFC) forms is investigated as a reinforcing agent in low-density polyethylene (LDPE) nanocomposites. The effect of extraction processing on the pulverized cotton is shown to influence the degree of crystallinity, morphology, and thermal stability of cellulose nanomaterials. Melt compounding of CNC with LDPE resulted in polymer nanocomposites with no discoloration at 170 °C. Significant differences observed in transparency, mechanical, and thermal properties of LDPE nanocomposite films, are demonstrated to be a result of the microstructure and the content of cellulose nanomaterials. Thermal analysis using thermogravimetric analyzer and differential scanning calorimeter showed higher thermal stability and degree of crystallinity of NFC/LDPE comparing to CNC/LDPE nanocomposite films. Tensile analysis exhibited a higher elastic modulus and tensile strength for the NFC material. 10 wt% of NFC reinforcing agent showed 32% improved strength and higher transparency over the one with CNC.
KeywordsBacterial Cellulose High Aspect Ratio Percolation Threshold LDPE Nanocomposite Film
The authors gratefully acknowledge financial support from Cotton Inc. (12-358). The cooperation of MeadWestvaco Company to process NFC-pCot is also greatly appreciated. We also thank Prof. Behnam Pourdeyhimi and the N.C. State Nonwovens Institute for providing LDPE polymer and NCRC characterization facilities.
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