Selective aminolysis of acetylated lignin: Toward simultaneously improving thermal-oxidative stability and maintaining mechanical properties of polypropylene

Dezhan Ye; Jinfeng Kong; Shaojin Gu; Yingshan Zhou; Caoxing Huang; Weilin Xu; Xi Zhang

doi:10.1016/j.ijbiomac.2017.10.168

Selective aminolysis of acetylated lignin: Toward simultaneously improving thermal-oxidative stability and maintaining mechanical properties of polypropylene

Int J Biol Macromol. 2018 Mar:108:775-781. doi: 10.1016/j.ijbiomac.2017.10.168. Epub 2017 Oct 27.

Authors

Dezhan Ye¹, Jinfeng Kong², Shaojin Gu³, Yingshan Zhou², Caoxing Huang⁴, Weilin Xu⁵, Xi Zhang⁶

Affiliations

¹ State Key Laboratory Cultivation Base for New Textile Materials & Advanced Processing Technology, Wuhan Textile University, Wuhan 430200, China; State Key Laboratory of Polymer Material Engineering, Sichuan University, Chengdu 610065, China; School of Materials Science and Engineering, Wuhan Textile University, 430200, China. Electronic address: [email protected].
² School of Materials Science and Engineering, Wuhan Textile University, 430200, China.
³ State Key Laboratory Cultivation Base for New Textile Materials & Advanced Processing Technology, Wuhan Textile University, Wuhan 430200, China; School of Materials Science and Engineering, Wuhan Textile University, 430200, China.
⁴ Co-Innovation Center for Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China.
⁵ State Key Laboratory Cultivation Base for New Textile Materials & Advanced Processing Technology, Wuhan Textile University, Wuhan 430200, China.
⁶ State Key Laboratory of Polymer Material Engineering, Sichuan University, Chengdu 610065, China. Electronic address: [email protected].

PMID: 29111268
DOI: 10.1016/j.ijbiomac.2017.10.168

Abstract

Even with outstanding radical capturing ability, the utilization of lignin as a natural antioxidant in polypropylene (PP) still has been pended. Usually, the compatibility of its blends is improved based on the reaction of hydroxyl content, thus leading to the decreasing content of phenolic hydroxyl (Ph-OH) group and inferior thermal-oxidative stability of lignin blends. Here, the selective aminolysis of acetylated Kraft lignin (pyr-KL) was investigated, which structures were characterized using FTIR, ³¹P-NMR and GPC. The Ph-OH group of acetylated KL could be released by the addition of pyrrolidine; however the aliphatic hydroxyl group is still blocked. With the control of reaction conditions, the highest oxidation induction time of pyr-KL/PP (0.5wt% loading) reaches up to 22.6min, almost 2.6 times than that of pure PP. More importantly, the mechanical properties of PP were also maintained under the loading of pyr-KL, which is much better than that of curde KL/PP.

Keywords: Lignin; Polypropylene; Selective aminolysis.

MeSH terms

Acetylation
Hydrolysis
Lignin / chemistry*
Lignin / metabolism
Mechanical Phenomena
Molecular Weight
Oxidation-Reduction
Oxidative Stress
Polypropylenes / chemistry
Spectroscopy, Fourier Transform Infrared
Thermodynamics

Substances

Polypropylenes
Kraft lignin
Lignin