caa a22 4500 37890308X CHVBK 20180305123522.0 cr unu---uuuuu 161128e20041201xx s 000 0 eng 10.1515/epoly.2004.4.1.751 doi (NATIONALLICENCE)gruyter-10.1515/epoly.2004.4.1.751 Turbulent drag reduction characteristics of amylopectin and its derivative [Elektronische Daten] [Sung Taek Lim, Hyoung Jin Choi, Diptirani Biswal, Ram Prakash Singh] Using amylopectin (AP) and a derivative, we systematically investigated their turbulent drag reduction characteristics and shear stability. The expected shear stability of polysaccharides as drag reducing and flocculating agents triggered our study on structural modification of AP. For this purpose, we prepared a derivative of AP, viz. AP grafted with polyacrylamide (GA), in which the granular form of AP powder (≈10 μm) changed into a mixture of larger fibrils and lumps. Using a rotating-disk apparatus, we measured the shaft torque and calculated the turbulent drag reduction (DR) efficiency under various experimental conditions, i.e., different polymer concentration, rotation speed, and temperature. Contrary to AP, GA showed relatively high DR efficiencies (27%) and very strong shear resistance. © 2013 by Walter de Gruyter GmbH & Co. Lim Sung Taek Department of Polymer Science and Engineering, Inha University, Incheon 402-751, Korea; Fax +82-32-865-5178 aut Choi Hyoung Jin Department of Polymer Science and Engineering, Inha University, Incheon 402-751, Korea; Fax +82-32-865-5178 aut Biswal Diptirani Materials Science Centre, Indian Institute of Technology, Kharagpur 721302, India aut Singh Ram Prakash Materials Science Centre, Indian Institute of Technology, Kharagpur 721302, India aut e-Polymers De Gruyter 4/1(2004-12-01), 751-760 2197-4586 4:1<751 2004 4 epoly https://doi.org/10.1515/epoly.2004.4.1.751 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/epoly.2004.4.1.751 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lim Sung Taek Department of Polymer Science and Engineering, Inha University, Incheon 402-751, Korea; Fax +82-32-865-5178 aut NATIONALLICENCE 700 1- Choi Hyoung Jin Department of Polymer Science and Engineering, Inha University, Incheon 402-751, Korea; Fax +82-32-865-5178 aut NATIONALLICENCE 700 1- Biswal Diptirani Materials Science Centre, Indian Institute of Technology, Kharagpur 721302, India aut NATIONALLICENCE 700 1- Singh Ram Prakash Materials Science Centre, Indian Institute of Technology, Kharagpur 721302, India aut NATIONALLICENCE 773 0- e-Polymers De Gruyter 4/1(2004-12-01), 751-760 2197-4586 4:1<751 2004 4 epoly CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter