Functionalized lignin by grafting phosphorus-nitrogen improves the thermal stability and flame retardancy of polypropylene

Yu, Youming and Fu, Shenyuan and Song, Ping'An ORCID: https://orcid.org/0000-0003-1082-652X and Luo, Xiping and Jin, Yongming and Lu, Fengzhu and Wu, Qiang and Ye, Jiewang (2012) Functionalized lignin by grafting phosphorus-nitrogen improves the thermal stability and flame retardancy of polypropylene. Polymer Degradation and Stability, 97 (4). pp. 541-546. ISSN 0141-3910


Abstract

Improving the thermal stability and flame retardancy of polymers remains a great challenge. Although lignin has been used as a flame retardant for polymers, its flame retardancy effect is usually limited. We, herein, successfully modified alkali lignin by chemically grafting two flame retardant elements, phosphorous and nitrogen, via a three-step reaction. Compared with lignin, modified lignin (PN-lignin) exhibits a much higher char-forming ability with a char of 61.4 wt% (40.7 wt% for lignin) at 600°C in N 2. PN-lignin confers a much higher thermal stability and amount of char residue on polypropylene relative to lignin. Moreover, PN-lignin further reduces the heat release rate and slows the combustion process, indicating a better flame retardancy. The continuous and intact char layer mainly contributes to the improved flame retardancy. This strategy not only provides a novel method for flame retarding polymeric materials, but greatly extends the comprehensive utilization of industrial lignin.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 30 May 2017 04:42
Last Modified: 30 May 2017 04:42
Uncontrolled Keywords: lignin modification; polypropylene; thermal stability; alkali lignin; char residues; combustion pro-cess; flame retardancy; functionalized; heat release rates; lignin modification; modified lignins; thermodynamics
Fields of Research (2008): 03 Chemical Sciences > 0303 Macromolecular and Materials Chemistry > 030301 Chemical Characterisation of Materials
Socio-Economic Objectives (2008): E Expanding Knowledge > 97 Expanding Knowledge > 970103 Expanding Knowledge in the Chemical Sciences
Identification Number or DOI: https://doi.org/10.1016/j.polymdegradstab.2012.01.020
URI: http://eprints.usq.edu.au/id/eprint/31639

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