title: Synthesis and characterization of hydrolysed starch-g-poly(methacrylic acid) composite.
abstract: A novel method for the synthesis of starch-g-poly(methacrylic acid) composite was adopted by graft polymerization of hydrolysed starch (HS) and methacrylic acid (MAA) in aqueous medium using an efficient sodium perborate (SPB)-thiourea (TU) redox initiation system. The parameters influencing the redox system efficiency and thence the polymerization method were considered. These parameters comprehended the concentrations of MAA, SPB, TU and SPB/TU molar ratio as well as the polymerization temperature. The polymerization reaction was scrutinized through calculation of the MAA total conversion percent (TC%). The resultant poly(MAA-HS) composite was assessed by evaluating the polymer criteria (the graft yield, GY%; the grafting efficiency, GE%; the homopolymer, HP%; and the total conversion). The comportment of the apparent viscosity of the cooked poly(MAA)-starch composite paste, obtained under diverse polymerization conditions, was examined. Tentative mechanisms, which depict all occasions that happen amid the entire course of the polymerization reaction, have been proffered.
authors.affiliation: Chemistry Department, Faculty of Science, Helwan University, Ain-Helwan, Cairo 11795, Egypt. Electronic address: magdy_zahran@yahoo.com.
authors.forename: Magdy K
authors.initials: MK
authors.lastname: Zahran
authors.affiliation: Department of Chemical Engineering & Pilot Plant, National Research Centre, Dokki, Cairo, Egypt.
authors.forename: Enas M
authors.initials: EM
authors.lastname: Ahmed
authors.affiliation: Pre-treatments and Finishing Department, National Research Centre, Dokki, Cairo, Egypt.
authors.forename: Mohamed H
authors.initials: MH
authors.lastname: El-Rafie
mesh_terms: D001881:Borates / Q000737:chemistry; D060326:Chemistry Techniques, Synthetic; D006868:Hydrolysis; D058105:Polymerization; D011109:Polymethacrylic Acids / Q000138:chemical synthesis* / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D013696:Temperature; D013890:Thiourea / Q000737:chemistry
chemical_list: D001881:Borates; D011109:Polymethacrylic Acids; C030613:polymethacrylic acid; D013213:Starch; D013890:Thiourea; C027707:sodium perborate
keywords: Characterization; Composite; Starch