Chemical and nanomechanical analysis of rice husk modified by ATRP-grafted oligomer

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:360

Article

Morsi, Samir M.^1,3  Pakzad, Anahita²  Amin, Amal³  Yassar, Reza S.²  Heiden, Patricia A.¹ 

[1] Michigan Technol Univ, Dept Chem, Houghton, MI 49931 USA

[2] Michigan Technol Univ, Dept Mech Engn Engn Mech, Houghton, MI 49931 USA

[3] Natl Res Ctr, Chem Ind Div, Polymer & Pigment Dept, Cairo, Egypt

关键词: Rice husk;    Nanomechanical;    Heterogeneous ATRP;    Macroinitiator;    Surface modification;    Grafting;   

DOI  :  10.1016/j.jcis.2011.04.065

来源: Elsevier

【 摘 要 】

Rice husk (RH), an abundant agricultural residue, was reacted with 2-bromoisobutyryl bromide, to convert it to a heterogeneous polyfunctional macroinitiator for Atom Transfer Radical Polymerization (ATRP). The number of active sites placed on the RH surface was small, but they were ATRP active. Non-polar methyl methacrylate (MMA) and polar acrylonitrile (AN) were polymerized from the RH, and a sequential monomer addition was used to prepare an amphiphilic PMMA-b-PAN copolymer on RH surface. FTIR qualitatively confirmed the grafting. Gravimetric and XPS analysis of the different RH surface compositions indicated thin layers of oligomeric PMMA, PAN, and PMMA-b-PAN. The modified surfaces were mapped by nanomechanical AFM to measure surface roughness, and adhesion and moduli using the Derjaguin-Muller-Toropov model. RH grafted with MMA possessed a roughness value of 7.92, and a hard and weakly adhering surface (13.1 GPa and 16.7 nN respectively) while RH grafted with AN yielded a roughness value of 29 with hardness and adhesion values of 4.0 GPa and 23.5 nN. The PMMA-b-PAN modification afforded a surface with a roughness value of 51.5 nm, with hardness and adhesion values of 3.0 GPa and 75.3 nN. (C) 2011 Elsevier Inc. All rights reserved.

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