Agricultural and Biosystems Engineering Publications
Campus Units
Center for Industrial Research and Service (CIRAS), Horticulture, Materials Science and Engineering, Ecology, Evolution and Organismal Biology, Agricultural and Biosystems Engineering
Document Type
Article
Publication Version
Accepted Manuscript
Publication Date
2014
Journal or Book Title
Green Chemistry
Volume
16
Issue
4
First Page
1911
Last Page
1920
Research Focus Area(s)
Biological and Process Engineering and Technology
DOI
10.1039/C3GC41503A
Abstract
The extensive use of plastics in agriculture has increased the need for development and implementation of polymer materials that can degrade in soils under natural conditions. The biodegradation behavior in soil of polyhydroxyalkanoate (PHA) composites with 10 wt% distiller's dried grains with solubles (DDGS) was characterized and compared to pure PHA over 24 weeks. Injection-molded samples were measured for degradation weight loss every 4 weeks, and the effects of degradation times on morphological, thermomechanical, and viscoelastic properties were evaluated by scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), and small-amplitude oscillatory shear flow experiments. Incorporation of DDGS had a strong effect on biodegradation rate, mechanical properties, and production cost. Material weight loss increased linearly with increasing biodegradation time for both neat PHA and the PHA/DDGS 90/10 composites. Weight loss after 24 weeks was approximately six times greater for the PHA/DDGS 90/10 composites than for unaltered PHA under identical conditions. Rough surface morphology was observed in early biodegradation stages (≥8 weeks). With increasing biodegradation time, the composite surface eroded and was covered with well-defined pits that were evenly distributed, giving an areolate structure. Zero shear viscosity, Tg, gelation temperature, and cold crystallization temperature of the composites decreased linearly with increasing biodegradation time. Addition of DDGS to PHA establishes mechanical and biodegradation properties that can be utilized in sustainable plastics designed to end their lifecycle as organic matter in soil. Our results provide information that will guide development of PHA composites that fulfill application requirements then degrade harmlessly in soil.
Copyright Owner
The Royal Society of Chemistry
Copyright Date
2014
Language
en
File Format
application/pdf
Recommended Citation
Madbouly, Samy A.; Schrader, James A.; Srinivasan, Gowrishankar; Liu, Kunwei; McCabe, Kenneth; Grewell, David A.; Graves, William R.; and Kessler, Michael R., "Biodegradation behavior of bacterial-based polyhydroxyalkanoate (PHA) and DDGS composites" (2014). Agricultural and Biosystems Engineering Publications. 836.
https://lib.dr.iastate.edu/abe_eng_pubs/836
Included in
Bioresource and Agricultural Engineering Commons, Horticulture Commons, Polymer and Organic Materials Commons
Comments
This is a manuscript of an article published as Madbouly, Samy A., James A. Schrader, Gowrishankar Srinivasan, Kunwei Liu, Kenneth G. McCabe, David Grewell, William R. Graves, and Michael R. Kessler. "Biodegradation behavior of bacterial-based polyhydroxyalkanoate (PHA) and DDGS composites." Green Chemistry 16, no. 4 (2014): 1911-1920. DOI: 10.1039/C3GC41503A. Posted with permission.