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Asan, South Korea

Lee J.W.,Kongju National University | Ku S.G.,Kongju National University | Lee B.H.,Kongju National University | Lee K.-W.,Hanyang Advanced Materials Co. | And 3 more authors.
Applied Chemistry for Engineering | Year: 2015

Polypropylene (PP)/bamboo fiber (BF) composites were fabricated by twin screw extruder in order to investigate effects of the compatibilizer on physical properties of PP/BF composites. The content of BF changed from 10 to 25 wt% and that of the compatibilizer was fixed at 3 wt%. Maleic anhydride grafted PP (PP-g-MAH) was used to increase the compatibility be- tween PP and BF as a compatibilizer. Chemical structures of the composites were confirmed by the existence of carbonyl group (C=O) stretching peak at 1,700 cm-1 in FT-IR spectrum. Considering the degradation and mechanical properties, the optimum extrusion conditions were selected to be 210 ℃ and 100 rpm, respectively. There was no distinct changes in melting temperature of the composites, but the crystallization temperature increased by 10-20 ℃ owing to the heterogeneous nuclei of BF. It was checked that the optimum BF content was in the range of 15-20 wt% from the results of tensile and flexural properties of the composites. The effect of the compatibilizer on mechanical properties was confirmed by SEM images of fractured surface and contact angles. © 2014 The Korean Society of Industrial and Engineering Chemistry. All rights reserved. Source

Lee J.W.,Kongju National University | Kim J.H.,Kongju National University | Ji S.-G.,Hanilewha | Kim K.S.,Hanilewha | Kim Y.C.,Kongju National University
Polymer (Korea) | Year: 2015

High density polyethylene (HDPE)/themally expandable microcapsule (EMC) and HDPE/EMC/Kenaf composites were fabricated by a twin screw extruder. Based on the foaming behavior of HDPE/EMC composites with screw rpm, content of EMC and die temperature, the optimum foaming conditions were selected 40 rpm, 5 wt%, and 160 °C. Foaming behavior and physical properties of HDPE/KenafEMC composites were evaluated at the selected foaming con-ditions and the length of Kenaf fiber was controlled at 1, 3, and 5 mm. PE-g-maleic anhydride (MAH) was also used to increase compatibility between HDPE and Kenaf as a compatibilizer. Thermal properties of HDPE/EMC and HDPE/ Kenaf/EMC composites were investigated by DSC and TGA, and there was no district change in thermal properties. It was checked that the applicable EMC content was below 20 wt% from the results of mechanical properties, specific gravity, and water uptake of HDPE/KenafEMC composites. The effect of the compatibilizer on foaming behavior was confirmed by cell structure measured by SEM. The rheological properties of the composites were investigated by dynamic rheometer. The complex viscosity and shear thinning effect of the composites increased with Kenaf contents and the effect was obvious in case of the composites with the compatibilizer. © 2015 The Polymer Society of Korea. All rights reserved. Source

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