Browsing by Author "Ngaowthong, Chakaphan"

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    Effect of dielectric barrier discharge plasma surface treatment on the properties of pineapple leaf fiber reinforced poly(Lactic acid) Biocomposites
    (Trans Tech Publications Ltd, 2016-01-01) Borůvka, Martin; Ngaowthong, Chakaphan; Běhálek, Luboš; Habr, Jiří; Lenfeld, Petr
    Plant source-based stiff fiber reinforced bioplastics based on natural plant derived substances show promise of providing degradation back into the environment when they are no longer needed. These "green" composites have enormous potential to replace materials originated from non-renewable resources and may turn out to be one of the material revolutions of this century. Unlike synthetic composites, "green" composites are renewable, carbon neutral, biodegradable, nonpetroleum based, and have low environmental, human health and safety risks. In this paper effect of pineapple leaf fiber (PALF) length and physical surface treatment on to the properties of the composites was investigated at 10% wt. loading. In order to improve compatibility and composite properties of PALF/poly(lactic acid) composites without any hazardous chemicals that are usually involved in the process, dielectric barrier discharge (DBD) plasma surface treatment was conducted for fiber modification. Therefore more environmentally friendlier and industrially scalable technology was implemented in processing of composites by twin screw extrusion and injection moulding. Resulted composites were characterized by means of scanning electron microscopy (SEM), thermal and mechanical testing. © 2016 Trans Tech Publications, Switzerland.
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    Recycling of sisal fiber reinforced polypropylene and polylactic acid composites: Thermo-mechanical properties, morphology, and water absorption behavior
    (2019-01-01) Ngaowthong, Chakaphan; Borůvka, Martin; Běhálek, Luboš; Lenfeld, Petr; Švec, Martin; Dangtungee, Rapeephun; Siengchin, Suchart; Rangappa, Sanjay Mavinkere; Parameswaranpillai, Jyotishkumar
    The effect of recycling on the thermo-mechanical and water absorption behavior of polypropylene (PP)/sisal fiber and polylactic acid (PLA)/sisal fiber composites were studied. The PP-based non-biodegradable composites and PLA-based biodegradable composites were recycled for four times. The effect of recycling was determined by examining the morphology, thermo-mechanical properties, and water absorption behavior and the obtained results were compared. The results showed that the incorporation of sisal fibers in the PP and PLA matrix enhances the tensile modulus and percentage crystallinity of the composites. The tensile strength and modulus of the sisal fiber reinforced PP composites were not affected with recycling. Even though the tensile properties of PLA and PLA/sisal fiber reinforced composites are superior to PP and PP/sisal fiber composites, the PLA-based composites show a dramatic decrease in tensile strength and modulus after the first recycling due to the degradation of the polymer. The thermal stability of the PP/sisal fiber composites was not affected by the repeated recycling process. On the other hand, the PLA-based composites with higher sisal fiber content show a bit lower thermal stability after recycling. The PP-based composites show fluctuations in percentage crystallinity with recycling. On the other hand, a remarkable increase in percentage crystallinity for PLA and PLA-based composites was observed with increasing recycling times. Water diffusion study divulges that the diffusion of water into the polymer composites was reduced with recycling, irrespective of the polymer matrix.