Palikir - National Government Center, Micronesia
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Tisserat B.,National United University | Reifschneider L.,Illinois State University | O'Kuru R.H.,Bio oils Research Unit | Finkenstadt V.L.,Plant Polymer Research Unit
BioResources | Year: 2013

Dried Distillers Grain with Solubles (DDGS) was evaluated as a bio-based fiber reinforcement. Composites of high density polyethylene (HDPE) composed of 25% by weight DDGS and either 0% or 5% by weight of maleated polyethylene (MAPE) were produced by twin screw compounding and injection molding. An improved DDGS bio-filler was produced by solvent treating DDGS (STDDGS). Injection-molded test specimens were evaluated for their tensile, flexural, impact, and thermal properties. Composite blends composed of STDDGS were superior to their DDSG counterparts. Composites made with STDDGS and MAPE had significantly improved tensile and flexural properties compared to neat HDPE. Impact strength of all composites was similar and lower than neat HDPE. Soaking of tensile bars of the various PE-DDGS blends in distilled water for 28 days altered their physical, color, and mechanical properties. Differential scanning calorimetery and thermogravimetric analysis were conducted on neat HDPE and DDGS composites to evaluate their thermal properties.


Tisserat B.,National United University | Selling G.W.,Plant Polymer Research Unit | Byars J.A.,National United University | Stuff A.,National United University
Journal of Polymers and the Environment | Year: 2012

Solid glycerol citrate polyester polymeric foams generated by microwave heating were further cured in a conventional oven at 100 °C for 0, 6, 24, 48, or 72 h and their physical properties were tested. Curing glycerol citrate polyesters resulted in decreased moisture content (MC), altered color, increased hydrated polymer weight loss (HWL), and increased polymer oven weight loss (OWL). Polyester polymer samples were evaluated for firmness and springiness employing a texture analyzer (Model TA/TX2i). Oven curing increased polymer firmness and springiness. For example, firmness and springiness in 48 h cured samples increased 202 and 143%, respectively, when compared to uncured controls. High correlations were found comparing OWL, MC, HWL, firmness, and springiness. Compression molded samples obtained from ground cured and non-cured polymers were evaluated for tensile strength, elongation and Young's modulus using the Instron universal test machine (Model 4201). Curing promoted higher tensile strengths and elongation but did not affect Young's modulus values. High correlations were found between springiness, firmness, tensile strength, and elongation. The texture analyzer was shown to have merit in the preliminary evaluation of the glycerol citrate polyester polymers. © 2011 Springer Science+Business Media, LLC (Outside the USA).


Fanta G.F.,Plant Polymer Research Unit | Felker F.C.,Functional Foods Research Unit | Selling G.W.,Plant Polymer Research Unit
Starch/Staerke | Year: 2016

Water-soluble amylose-inclusion complexes were prepared from high amylose corn starch and the sodium salts of lauric (C12), palmitic (C16), and stearic (C18) acid by steam jet cooking. Cast films plasticized with glycerol were prepared by combining solutions of the amylose complexes and poly(vinyl alcohol) (PVOH) at ratios varying from 100:0 to 0:100. All amylose complex formulations up to 60% incorporation had percent elongations equivalent to or greater than the PVOH control. Tensile strength was similar to control films up to 40% incorporation of the C16 complex. All films prepared from these amylose complexes had tensile properties superior to composite films containing uncomplexed corn starch. Contact angles of water droplets showed that incorporation of as little as 20% amylose complex yielded films with increased surface hydrophobicity. Microscopy of iodine-stained films showed that the films contained a starch-rich phase and a continuous unstained background of PVOH. Surface roughness and the close proximity of the micron-sized areas of starch complex may contribute to the high contact angles observed at low concentrations of complex. This study enables production of PVOH films containing substantial levels of biobased starch, a good balance of physical properties, and greatly increased surface hydrophobicity relative to the PVOH control. Published 2016.


Tisserat B.,National United University | Finkenstadt V.L.,Plant Polymer Research Unit
Journal of Polymers and the Environment | Year: 2011

Ribbons of poly(lactic acid) (PLA) and PLA containing 10 or 25% Osage Orange (OO) biocomposites of various sized heartwood particles were exposed to non-composting soil conditions either outdoors or in a greenhouse. No appreciable degradation was evident after 208 day treatments. An artificial alkaline degradation test system was developed to reduce the study time required to evaluate PLA compositional properties on degradation. Ribbons of PLA and PLA-OO biocomposites of various sized particles were subjected to hydrolysis in alkaline concentrations (0, 0. 05, 0. 1, 0. 15, and 0. 25 M NaOH) under various temperatures (15, 20, 25, 30, 35, 40, and 80 °C) up to 56 days. Higher concentrations of NaOH (e. g., 0. 25 M) caused more dramatic and rapid deterioration of PLA and PLA-OO composites than lower NaOH concentrations for all temperatures tested. Incubation in either the low temperatures (15 and 20 °C) or the highest temperature (80 °C) was consistently more effective in PLA-OO degradation than employing 35 or 40 °C. Several alkaline and temperature test combinations are offered to study accelerated PLA degradation. Ribbons immersed in NaOH were examined with the scanning electron microscope to analyze for morphological alterations. © 2011 Springer Science+Business Media, LLC (outside the USA).


Tisserat B.,National United University | Reifschneider L.,Illinois State University | Joshee N.,Fort Valley State University | Finkenstadt V.L.,Plant Polymer Research Unit
Journal of Thermoplastic Composite Materials | Year: 2015

Paulownia wood flour (PWF), a by-product of milling lumber, was employed as a biofiller and blended with high-density polyethylene (HDPE) via extrusion. Paulownia wood (PW) shavings were milled through a 1-mm screen and then separated via shaking into various particle fractions (600-≤74 μm) using sieves (#30->#200 US Standards). The influence of a commercial coupling agent, maleated polyethylene (MAPE), used at various concentrations (0, 1, 3, 5, or 10% w/w) with HDPE and wood particles obtained from a #50-mesh sieve, is examined. Incorporation of high concentrations of MAPE (approximately 5%) in HDPE-PWF blends improved tensile strength compared to lower MAPE concentrations (‰3%). Particle size of wood significantly influenced the mechanical properties of the biocomposite. HDPE-MAPE blends containing smaller wood particles (<180 μm) had higher tensile strength than neat HDPE or blends containing larger particles (>300 μm). Young;euros modulus for all HDPE-PWF-MAPE blends was 14-27% higher than that of neat HDPE. Generally, incubation of tensile bars of various HDPE-PWF blends in 95% humidity for 28 days reduced the mechanical properties approximately by 5%. Differential scanning calorimetry analysis showed a slight reduction in the percentage crystallinity among various HDPE-PW blends. © The Author(s) 2013.

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