Thermoformable Automotive Composites Containing Kenaf and Other Cellulosic Fibers

Abstract

Currently, there is a major upsurge in research on the use of recyclable and biodegrad able materials in manufactured products. This has triggered a need for biodegradable nonwovens for nearly forty automotive interior components, which currently contain traditional materials such as glass and other manufactured fibers and foams that are difficult to recycle. By incorporating agricultural lignocellulosic (bast) fibers such as kenaf, jute, hemp, and flax in the manufacture of automotive nonwovens, their biode gradability can be enhanced. Because of the different densities of kenaf and glass fibers, kenaf-based nonwovens may be lighter than those containing glass fibers, which may lead to lightweight, "green" automotive interiors. Furthermore, preliminary research has shown that several cellulosic-based (kenaf, jute, and other less expensive vegetable/bast fibers) nonwovens are efficient sound absorbers and reduce the noise level in cars. Overall, these nonwovens meet or exceed industry specifications of flammability, odor, mildew, bond strength, drapeability and tensile strength, elongation, and compression properties. In this paper, we briefly describe the fabrication and physical, mechanical, and acoustical properties of needlepunched thermoformable nonwoven fabrics for certain automotive interior applications. These nonwoven fabrics were developed using optimally retted kenaf and jute fibers in various blends with greige cotton, recycled polyester, and off-quality polypropylene. Successful use of kenaf fibers in automotive nonwovens would be environmentally benign and should lead to a considerable expansion in kenaf cultiva tion.

Implantation site of rare earths in single-crystalline ZnO

“…Since it was experimentally observed that the rare earth luminescence efficiency at room temperature increases with the band gap of the semiconductor [2], wide band gap materials such as GaN are especially promising for possible applications. Rare earth luminescence from Nd, Sm, Eu, Tb, Dy, Ho, Er and Tm has also been reported in the hexagonal II-VI semiconductor ZnO [3][4][5][6][7][8][9][10][11][12]. Interest in zinc oxide has recently increased due to the fact that its structural and semiconducting properties are similar to hexagonal GaN, but that, in comparison to GaN, highquality single crystals of ZnO are easier to grow [13].…”

“…Several methods for producing RE-doped ZnO have been described in the literature, including sintering [3][4][5], wet-chemical synthesis [6,11], laser ablation [7-10] and co-deposition following evaporation [12]. However, all these methods result in polycrystalline samples, and there exists evidence that the rare earths accumulate at the grain boundaries of polycrystalline ZnO [4].…”

Benefits of low kenaf loading in biobased composites of poly(L‐lactide) and kenaf fiber

“…[26][27][28][29] Incorporating kenaf in the manufacture of automotives not only increased their biodegradability but also reduced their weight and enhanced their noise absorbent ability. Parikh et al 30 found that nonwovens made of retted kenaf blended with cotton fibers, recycled polyester, and off-quality polypropylene could meet industry specifications of flammability, odor, mildew, and strength. Mueller and Krobjilowski 31 have studied the formation of composites by using flax fibers and biodegradable melt-blown polymeric materials as the matrix.…”

The Effect of Synthesis Pressure on Properties of Eu-Doped ZnO Nanopowders Prepared by Microwave Hydrothermal Method

“…This corresponds with MCS calculations. In all cases, no emission related to Eu 3+ was observed, because the excitation wavelength is lower than 385 nm [23] and the 4.7 eV (260 nm) photons are not in resonance with any transitions of Eu 3+ ions. It is also worth noting that the intensity ratio of I NBE to I DLE is increasing with the synthesis pressure, as seen in Fig.…”