Font Size: a A A

Study Of Polyoxometalate Catalyst For Production Of Carboxylic Acids From Starch With Hydrogen Peroxide

Posted on:2014-08-29Degree:MasterType:Thesis
Country:ChinaCandidate:Bouasavanh SouvanhthongFull Text:PDF
GTID:2251330401981477Subject:Inorganic chemistry
Abstract/Summary:PDF Full Text Request
Starch as one of most renewable nature biopolymers,because of its relativelyinexpensive and abundant availability, has proven to be an important subject for the researchof materials from biomass. As the rapid development of science technology, the intrinsicproperties of native starch, like the structure and performance, had suffered great limits in theapplication of modern manufacture with new technique and devices. Oxidation of starch is animportant branch of modiifed starch. Compared with native starch, it owns much moreextensive application in paper, textile, food and many other modern industrial areas becauseof its quality characteristics, such as easy pasting, low viscosity, high thermal stability, hightransparency, good iflm and good freeze-thaw resistance. Consequently, ifnding aneconomical and eiffcient method for the starch oxidation has a potential prospect.Polyoxometalate is attracting more and more attention because of its unique catalyticactivity such as it can be used as an acidic catalyst, and oxidation catalyst or a bio-functionalcatalyst in the homogeneous and heterogeneous systems.The present paper designed different Vanadium (V) substituted POMs (H3+n[PMoi2-nVn04o]where n=1-3) and organic hydride-POMs (((CH3)4N)x{H5-x[PMoioV204o]} where x=1,3and5) as catalyst and hydrogen peroxide as oxidant to prepare the oxidized starch under aneutral and mild condition. This work solves the drawbacks in the traditional oxidation ofstarch, such as the waste of large quantities of water and oxidant, environmental problemsdeduced from the oxidant unable to be retrieved in the homogeneous system. The catalystsenabled starch oxidized to carboxylic acid, and performance (degree of oxidation; DO) ofdifferent catalyst shows an apparent trends as different Vanadium (V) contain: H6PM09V3O40>H5PMo10V2O40〉H4PM011VO40and change acidic: H5PM010V2O40〉(CH3)4N {H4[PMoioV2O40]}>((CH3)4N)3{H2[PMoioV2〇4o]}〉((CH3)4N)5[PMoioV2〇4o]. It is an environmental friendlycatalyst for the starch oxidation.
Keywords/Search Tags:Polyoxometalates (POMs), Oxidation of starch, Hydrogen peroxide
PDF Full Text Request
Related items