Comparing Polymer-Supported TEMPO Mediators for Cellulose Oxidation and Subsequent Polyvinylamine Grafting

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• 作者：Shuxian Shi ; Robert Pelton ; Qiang Fu ; Songtao Yang
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：March 26, 2014
• 年：2014
• 卷：53
• 期：12
• 页码：4748-4754
• 全文大小：334K
• 年卷期：v.53,no.12(March 26, 2014)
• ISSN：1520-5045

文摘

A new poly(acrylic acid)-grafted TEMPO (PAA-T) is compared to polyvinylamine-grafted TEMPO and free TEMPO as oxidation mediators for cellulose. The polymer-immobilized mediators require lower overall TEMPO concentrations and they restrict oxidation to the exterior surfaces of porous cellulose. On the other hand, the resulting surfaces are coated with grafted polyvinylamine and laccase, if the enzyme is used as the primary oxidant. PAA-T is anionic and does not sufficiently adsorb onto anionic cellulose to give oxidation, whereas cellulose rendered cationic by an adsorbed layer of PVAm is oxidized by PAA-T + laccase. There is no clear 鈥渂est choice鈥?mediator/primary oxidant combination for cellulose oxidation subsequent to PVAm grafting; the advantages of each mediator are summarized.