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Papers by Edwards Roan
A high-content starch/low-density polyethylene (LDPE) blend with acceptable biodegradation and me... more A high-content starch/low-density polyethylene (LDPE) blend with acceptable biodegradation and mechanical properties was produced by adjusting the compatibility of the blend system and processing plasticisation through the compatibiliser and different processing method. Two kinds of compatibilisers, maleic anhydride grafted LDPE after plasma treatment (MA-g-PLDPE) and acrylic acid grafted LDPE after plasma treatment (AAc-g-PLDPE), were synthesized and used in this work. The grafting degree (GD) of MA-g-PLDPE was 1.90 ! 10 ÿ4 mol/g. The GD of AAc-g-PLDPE was 2.5 ! 10 ÿ4 mol/g. MA-g-PLDPE gave more compatibility than AAc-g-PLDPE by the anhydride groups. The plasticisation effect by the oligomer resulted from a different process by mixing the MA-g-PLDPE and/or maleic anhydride (MA) with glycerol before compounding was investigated. As the MA and compatibiliser/LDPE premixed with GA for 30 min, the LDPE particle size of blends decreased with increasing compatibiliser content. If the free MA was not added, the PE blends show irregular shapes. The weight loss of all samples achieved above 65 wt% after two weeks of biodegradation. The weight losses of blends that contain free MA were higher than those without free MA. Finally, the structure of blends after soil burial was observed by SEM.
Electromagnetic interference (EMI) shielding effectiveness (SE) of single-layer or double-layers ... more Electromagnetic interference (EMI) shielding effectiveness (SE) of single-layer or double-layers electroless metals, such as nickelyphosphorus-pure nickel (NiP-Ni), Ni-NiP, NiP-Cu, Ni-Cu, coated carbon fiber reinforced acrylonitrile-butadiene-styrene (ABS) composites was investigated. The resistivity and anti-oxidization of conductive fillers were important factors for EMI shielding composites. Although the resistivity of electroless copper-coated carbon fiber (ECCF) is much lower than that of electroless nickel-coated carbon fiber (ENCF), electroless copper films on the carbon fibers are readily oxidized during compounding processes. The resistivity of ECCFyABS composites increased significantly after composite fabrication. As a result, the EMI SE of ECCFyABS composite showed a poor EMI SE (37 dBm) among those electroless metals-coated carbon fiber reinforced ABS composites. The coated double layers electroless metals on the conductive fillers were obtained by electroless method. The outside metal layer, which possessed better anti-oxidization, provided suitable protection for the conductive fillers. Thus, the EMI SE of the ECCFyABS composite can improve effectively. The best EMI SE of double-layers electroless coated-metalsyABS composites could be reached 65 dBm. ᮊ
After 900 8C heat treatment in vacuum, electroless nickelyphosphorus (NiyP) alloy on the surface ... more After 900 8C heat treatment in vacuum, electroless nickelyphosphorus (NiyP) alloy on the surface of carbon fiber (CF) acts as a catalyst for the transformation of carbon to graphite. Although the resistivity of graphite was lower than that of carbon, it was broken by the blending roller during compounding processes. As a result, the composite, which was fabricated by 900 8C heattreated CF and ABS polymer, showed the poorest mechanical properties and electromagnetic interference (EMI) shielding effectiveness (SE) of various annealed electroless NiyP-coated carbon fiber (ENCF) reinforced ABS polymeric composites. When ENCF was heat-treated at 600 8C, the EMI SE and mechanical properties of composites were improved owing to the lower electrical resistivity, longer mean fiber length and the good interfacial bonding between NiyP and CF. ᮊ
A high-content starch/low-density polyethylene (LDPE) blend with acceptable biodegradation and me... more A high-content starch/low-density polyethylene (LDPE) blend with acceptable biodegradation and mechanical properties was produced by adjusting the compatibility of the blend system and processing plasticisation through the compatibiliser and different processing method. Two kinds of compatibilisers, maleic anhydride grafted LDPE after plasma treatment (MA-g-PLDPE) and acrylic acid grafted LDPE after plasma treatment (AAc-g-PLDPE), were synthesized and used in this work. The grafting degree (GD) of MA-g-PLDPE was 1.90 ! 10 ÿ4 mol/g. The GD of AAc-g-PLDPE was 2.5 ! 10 ÿ4 mol/g. MA-g-PLDPE gave more compatibility than AAc-g-PLDPE by the anhydride groups. The plasticisation effect by the oligomer resulted from a different process by mixing the MA-g-PLDPE and/or maleic anhydride (MA) with glycerol before compounding was investigated. As the MA and compatibiliser/LDPE premixed with GA for 30 min, the LDPE particle size of blends decreased with increasing compatibiliser content. If the free MA was not added, the PE blends show irregular shapes. The weight loss of all samples achieved above 65 wt% after two weeks of biodegradation. The weight losses of blends that contain free MA were higher than those without free MA. Finally, the structure of blends after soil burial was observed by SEM.
Electromagnetic interference (EMI) shielding effectiveness (SE) of single-layer or double-layers ... more Electromagnetic interference (EMI) shielding effectiveness (SE) of single-layer or double-layers electroless metals, such as nickelyphosphorus-pure nickel (NiP-Ni), Ni-NiP, NiP-Cu, Ni-Cu, coated carbon fiber reinforced acrylonitrile-butadiene-styrene (ABS) composites was investigated. The resistivity and anti-oxidization of conductive fillers were important factors for EMI shielding composites. Although the resistivity of electroless copper-coated carbon fiber (ECCF) is much lower than that of electroless nickel-coated carbon fiber (ENCF), electroless copper films on the carbon fibers are readily oxidized during compounding processes. The resistivity of ECCFyABS composites increased significantly after composite fabrication. As a result, the EMI SE of ECCFyABS composite showed a poor EMI SE (37 dBm) among those electroless metals-coated carbon fiber reinforced ABS composites. The coated double layers electroless metals on the conductive fillers were obtained by electroless method. The outside metal layer, which possessed better anti-oxidization, provided suitable protection for the conductive fillers. Thus, the EMI SE of the ECCFyABS composite can improve effectively. The best EMI SE of double-layers electroless coated-metalsyABS composites could be reached 65 dBm. ᮊ
After 900 8C heat treatment in vacuum, electroless nickelyphosphorus (NiyP) alloy on the surface ... more After 900 8C heat treatment in vacuum, electroless nickelyphosphorus (NiyP) alloy on the surface of carbon fiber (CF) acts as a catalyst for the transformation of carbon to graphite. Although the resistivity of graphite was lower than that of carbon, it was broken by the blending roller during compounding processes. As a result, the composite, which was fabricated by 900 8C heattreated CF and ABS polymer, showed the poorest mechanical properties and electromagnetic interference (EMI) shielding effectiveness (SE) of various annealed electroless NiyP-coated carbon fiber (ENCF) reinforced ABS polymeric composites. When ENCF was heat-treated at 600 8C, the EMI SE and mechanical properties of composites were improved owing to the lower electrical resistivity, longer mean fiber length and the good interfacial bonding between NiyP and CF. ᮊ