Surface Modification of Cellulose Nanofibrils for Reinforcement of Composites
- Luna Innovations, Inc., Roanoke, VA (United States)
Luna successfully demonstrated an in-situ surface treatment of cellulose nanofibrils (CNF) within a spray drying process that provided a CNF in a solid powder form with hydrophobic character. The spray drying process was optimized to provide hydrophobic CNF materials while adding the least amount of additional weight from the surface reaction. Luna was able to provide hundreds of grams of treated CNF materials to our partners at Virginia Tech for validation and dispersion within commercial thermoplastic (polypropylene). Formulation/compounding work with polypropylene revealed a significant improvement in compatibility of the treated CNF materials with the polymer matrix compared to freeze-dried and/or untreated CNF. Analysis of contact angle for the various modified CNF materials revealed an optimal window of loading level and alkyl chain length for maximizing dispersability. Using approximately 2 wt% of C8/C16 alkyl reagent in the spray drying process, Luna was able to create CNF additives that dramatically improve modulus properties of polypropylene composites even at loadings as low as 5 wt%. Initial economic analysis strongly supports the use of continuous spray drying for the preparation of solid CNF additives for use in composites over processes such as oven-drying or freeze-drying. Successful twin screw extrusion and injection molding of ASTM D638 Type V dogbones for tensile testing of unfilled MFR 2 PP, freeze dried CNF, unmodified spray dried CNF and 2% C16 spray dried CNF. Freeze dried material was unable to be mechanically processed. The 2% C16 spray dried CNF demonstrated clear dispersion advantages over the unmodified CNF versions, as well as improved tensile strength and hardness.
- Research Organization:
- Luna Innovations, Roanoke, VA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- Contributing Organization:
- Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
- DOE Contract Number:
- SC0017827
- OSTI ID:
- 1435797
- Type / Phase:
- SBIR (Phase I)
- Report Number(s):
- DOE-LUNA-SC-0017827; 3496.01
- Country of Publication:
- United States
- Language:
- English
Similar Records
Enhanced thermal reliability and performance of calcium chloride hexahydrate phase change material using cellulose nanofibril and graphene nanoplatelet
Enhanced Thermal Reliability and Performance of Calcium Chloride Hexahydrate Phase Change Material Using Cellulose Nanofibril and Graphene Nanoplatelet