|
|
|
|
Research Project:
YIELD AND QUALITY OF VEGETABLE CROPS IN CONVENTIONAL AND ORGANIC PRODUCTION SYSTEMS
Location: Lane, OK
Title: Benefits of low kenaf loading in biobased composites of Poly
(L-Lactide) and kenaf fiber
Authors
| Ogbomo, Sunny - UNIV. NORTH TEXAS | | Chapman, Kent - UNIV. NORTH TEXAS | | Bledsoe, Robert - INTERNATIONAL KENAF ASSOC | |
Webber, Charles
| | D'Souza, Nandika - UNIV. NORTH TEXAS |
Submitted to: Journal of Applied Polymer Science
Publication Type:
Peer Reviewed Journal
Publication Acceptance Date: October 15, 2008
Publication Date: N/A
Interpretive Summary: The need to replace fossil based materials has led to increased interest in biopolymer composites, specifically those containing natural fibers. Bast fibers from stems of kenaf (Hibiscus cannabinus L.), a warm-season herbaceous annual plant, were dispersed into Poly-L-Lactide (PLLA) matrix by melt mixing followed by compression molding. Low fiber fractions (1-5%) were investigated. The composites showed a slight lowering of thermal stability. Kenaf fibers influenced the crystallization of the PLLA. Analysis also indicated an increased matrix-fiber interaction. Increased interaction resulted in good fiber-matrix adhesion. The combination of dispersion, interaction and crystallinity enabled an increase in mechanical properties in the composite which scaled with concentration. These results established the feasibility of successfully fabricating PLLA-kenaf natural fiber composites with very low kenaf loading (1-5%). The enhancement in stiffness and crystallization rates compared well compared to 10, 20, 30% kenaf containing composites reported in previous research. The addition of kenaf to PLLA increased the storage modulus and thermal properties, while also improving the crystallization rate even at low kenaf loading. An interaction between PLLA and kenaf enabled good fiber wetting by the PLLA. These results are significant as we compare the conventional based filler with natural based filler fibers. We envision an increase movement to, or development of, safer, green, environmentally friendlier, and cheaper materials with a resulting improvement in mechanical properties.
Technical Abstract: Bast fibers from stems of kenaf (Hibiscus cannabinus L.), a warm-season herbaceous annual plant, were dispersed into Poly-L-Lactide (PLLA) matrix by melt mixing followed by compression molding. Low fiber fractions (1-5%) were investigated. The composites showed a slight lowering of thermal stability when evaluated by Thermogravimentric analysis (TGA). X-ray diffraction (XRD) and Differential scanning calorimetry (DSC) indicated an influence of kenaf on crystallization of the PLLA. Attenuated Total Reflectance-Fourier transfer infrared spectroscopy (ATR-FTIR) showed increased matrix-fiber interaction. Increased interaction resulted in good fiber-matrix adhesion as revealed by Scanning Electron Microscopy. The fiber dispersion in the polymer matrix was established by polarized optical microscopy. The combination of dispersion, interaction and crystallinity enabled an increase in mechanical properties in the composite which scaled with concentration. These results established the feasibility of successfully fabricating PLLA-kenaf natural fiber composites with very low kenaf loading (1-5%). The enhancement in stiffness and crystallization rates compared well compared to 10, 20, 30% kenaf containing composites in the literature. The addition of kenaf to PLLA increased the storage modulus and thermal properties, while improving the crystallization rate at low kenaf loading. An interaction between PLLA and kenaf was established by FTIR. The interaction enabled good fiber wetting by the PLLA as indicated by SEM. These results are significant as we compare the conventional based filler with natural based filler fibers. We envision an increase movement to, or development of safer, green, environmentally friendlier, and cheaper materials with a resulting improvement in mechanical properties.
|
|
|
|
|
|
Last Modified: 11/04/2008
|
|