Durability of Starch Based Biodegradable Plastics Reinforced with Manila Hemp Fibers
2. Experimental Procedures
2.2. Specimen molding method
2.3. Biodegradability tests
2.4. Evaluation of biodegradability
3. Results and Discussions
3.1. Mechanical properties
3.2. Biodegradation behavior
3.3. Microscopic observations
- In the case of composting, the tensile strength of Manila hemp fiber reinforced composites decreased 80% after 20 days. In the case of a natural atmosphere, the tensile strength of specimens in soil decreased 80% after 90 days. Furthermore, differences of condition could be seen between parts of a differentially exposed specimen; strength decreased for the part under soil more so than the part exposed to air.
- Weight loss of the specimen completely buried under the soil showed a value of approximately 1.8 times that of the specimen of which only half was buried under the soil at 240 days (45% vs. 25%, respectively). A weight loss of 30% was observed with the specimen in compost at 90 °C for 30 days and a similar level of weight loss was seen in natural environments at 180 days.
- The state of the parts of the specimens in soil changed remarkably. In the atmosphere, biodegradation is negligible. On the other hand, when the specimen interacts with microbes in either the natural or compost soil, weight, tensile strength and state of the specimen change remarkably.
- The decomposition sequence for MHFRP can be described as follows. The biodegradable resin at the specimen surface first decomposes, followed by exposure of the Manila hemp fiber bundles embedded within the resin. Next, the biodegradable resin in the vicinity of the fiber-resin interface decomposes, resulting in the formation of interfacial gaps. Finally, substantial decomposition of both the fibers and biodegradable resin occurs.
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Ochi, S. Durability of Starch Based Biodegradable Plastics Reinforced with Manila Hemp Fibers. Materials 2011, 4, 457-468. https://doi.org/10.3390/ma4030457
Ochi S. Durability of Starch Based Biodegradable Plastics Reinforced with Manila Hemp Fibers. Materials. 2011; 4(3):457-468. https://doi.org/10.3390/ma4030457Chicago/Turabian Style
Ochi, Shinji. 2011. "Durability of Starch Based Biodegradable Plastics Reinforced with Manila Hemp Fibers" Materials 4, no. 3: 457-468. https://doi.org/10.3390/ma4030457