Composites and nanocomposites
Hamed NazarpourFard
Abstract
Polyvinylpyrrolidone (PVP) composites based on rice husk (RH), rice husk carbon (RHC, i.e., black rice husk ash (BRHA)) and rice husk ash (RHA, i.e., white rice husk ash (WRHA)) were prepared separately through solution casting method. Similar composites were made using polystyrene (PS) through the same ...
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Polyvinylpyrrolidone (PVP) composites based on rice husk (RH), rice husk carbon (RHC, i.e., black rice husk ash (BRHA)) and rice husk ash (RHA, i.e., white rice husk ash (WRHA)) were prepared separately through solution casting method. Similar composites were made using polystyrene (PS) through the same protocol. The carbon and ash obtained from this type of rice husk were obtained via pyrolysis at 300 and 600 °C, respectively, for 1 hour. The effects of these additives on the spectroscopic characteristics of polymers were verified by examining the infrared (FT-IR) and X-ray diffraction (XRD) spectra of the prepared composites. The resulting showed a remarkable difference between the spectra of parent polymers and the corresponding composites. Changes in peak width and 2θ parameters (observed in XRD patterns) revealed that PVP possesses better interactions with RHC, while PS has better interactions with RHA. Due to the high hydrophilicity of PVP, some investigations were accomplished on the hydrophilic properties of PVP samples. Polystyrene did not reveal detectable water vapor absorption (WVA), thus this experiment was not carried out for PS samples. Eventually, it was disclosed that there are significant discrepancies between the hydrophilic properties of PVP and its composites. In the other word, the WVA decreased from 290% for parent PVP to 210% for PVP-RHC composite.
Composites and nanocomposites
Raid Banat; Malek Aljnaid; Manal Al-Rawashdeh
Abstract
Mechanical and physical properties of various weigh percentages (0% - 40%) of olive pomace flour (OPF)-loaded linear low density polyethylene (LLDPE) in the presence of 0%, 5% and 10% coupling agent (C) were formulated and studied. Extrusion and hot press processing techniques were used to fabricate ...
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Mechanical and physical properties of various weigh percentages (0% - 40%) of olive pomace flour (OPF)-loaded linear low density polyethylene (LLDPE) in the presence of 0%, 5% and 10% coupling agent (C) were formulated and studied. Extrusion and hot press processing techniques were used to fabricate OPF/LLDPE composites. Tensile stress at yield increased by 20% with the increasing of the filler loading up to 20%; and marginally increased in the presence of the C. Whereas, the decline in the tensile strain at yield of the polymer composite improved with the increase in the C content. The modulus increased from 631 MPa for the neat LLDPE to 680, 808 and 700 MPa for the composites filled by 5%, 10% and 20% filler content, respectively. Whereas, a decrease in the given modulus (550 MPa) was observed at 40% filler loading. The modulus has shown a successive improvement upon the addition of the C with values not less than 800 MPa. The impact strength decreased with the increase in filler loading from 119 kJ/m2 for the neat LLDPE to 81, 43, 27 and 16 kJ/m2 for the 5%, 10%, 20% and 40% OPF/LLDPE samples, respectively. On the contrary, 10% C addition improved the impact strength of the composite by two folds in the case of 10 - 40% filler inclusion. The scanning electron microscopy (SEM) illustrations proved the mechanical performance of various bio-composite formulations. Water absorption of the bio-composite increased with the OPF loading, from 0.73% for the neat LLDPE to 2.6% for 40% OPF-filled polymer composite, and decreased upon increasing the C content with an average of 1.4% for all composites. Formulated by mixing cellulosic-based material OPF and LLDPE, the bio-composite demonstrated compatible physical properties and can be used as an already available cellulosic filler for the bio-composite materials.
