Location: Dairy and Functional Foods ResearchTitle: Improving grafting efficiency of dicarboxylic anhydride monomer on polylactic acid by manipulating monomer structure and using comonomer and reducing agent Author
|Liu, Wangcheng - Washington State University|
|Liu, Tao - Washington State University|
|Liu, Tuan - Washington State University|
|Liu, Tian - Washington State University|
|Xin, Junna - Washington State University|
|Hiscox, Wiliam - Washington State University|
|Liu, Hang - Washington State University|
|Zhang, Jinwen - Washington State University|
Submitted to: Industrial and Engineering Chemistry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/20/2017
Publication Date: 3/20/2017
Citation: Liu, W., Liu, T., Liu, T., Liu, T., Xin, J., Hiscox, W.C., Liu, H., Liu, L.S., Zhang, J. 2017. Improving grafting efficiency of dicarboxylic anhydride monomer on polylactic acid by manipulating monomer structure and using comonomer and reducing agent. Industrial and Engineering Chemistry Research. 56:3920-3927. doi: 10.1021/acs.iecr.6b05051.
Interpretive Summary: Functional polymers are used for a wide range of applications, and their preparation methods are diverse as well. In recent years, the interest in renewable polymer materials has been growing continuously. Polylactic acid (PLA), a sugarbased biodegradable polyester, has received the most attention among all renewable polymers and has been frequently employed in multicomponent materials for enhanced performance. However, PLA shows insufficient compatibility, adhesion ability, paintability and reactivity in many applications. Therefore, functionalized PLA is necessary for improving its compatibility in such multicomponent systems.
Technical Abstract: Maleic anhydride (MA) grafted polylactic acid (PLA) acting as reactive compatibilizer for PLA blends and composites has been reported. However, melt free-radical grafting of MA on PLA is often subject to steric and electron effects of the substituents in the monomer and low initiation efficiency, yielding low grafting efficiency (E(g)). In this work, five dicarboxylic anhydride monomers, including MA, itaconic anhydride (IA), cis-1,2,3,6-tetrahydrophthalic anhydride (TA), 4-allyltrimellitate anhydride (ATA), and 4-methacryloxyethyl trimellitate anhydride (META), were grafted onto PLA, and the effect of steric hindrance on E(g) was assessed. It is noted that E(g) values followed the order of ATA > META » MA = TA > IA. The introduction of styrene as a comonomer selectively increased the Eg values of three electron-deficient monomers, MA, IA, and META, while Sn(Oct)(2) as a reducing agent increased E(g) for all monomers. Both styrene and Sn(Oct)(2) exhibited a synergistic effect when used in grafting MA, IA, and META.