Laccase-Facilitated Copolymerization of Lignin for the Synthesis of Novel Biomaterials

Transcription

1 Laccase-Facilitated Copolymerization of Lignin for the Synthesis of Novel Biomaterials Mark D. Cannatelli Dr. Arthur J. Ragauskas Renewable Bioproducts Institute Department of Chemistry Georgia Tech 1

2 Hyperbranched Lignin Copolymers Kraft Lignin Functionalized with PEGMA Combining with α-cyclodextrin produces hydrogels Mechanically responsive Self-healing properties No cytotoxicity D. Kai, Z. W. Low, S. S. Liow, A. A. Karim, H. Ye, G. Jin, K. Li, X. J. Loh, ACS Sustainable Chem. Eng. 2016, 3(9), Y. Zheng, S. Li, Z. Weng, C. Gao, Chem. Soc. Rev. 2015, 44,

3 Laccases Benzenediol : oxygen oxidoreductases EC: Multi-copper oxidases Fungi lignin degradation Plants lignin biosynthesis PDB: 1GYC U. N. Dw ivedi, P. Singh, V. P. Pandey, A. Kumar, J. Mol. Catal. B: Enzym. 2011, 68, B. Otto, D. Schlosser, W. Reisser, Arch. Microbiol. 2010, 192, M. D. Cannatelli, A. J. Ragauskas, Chem. Rec. 2017, 17(1), E. I. Solomon, A. J. Augustine, J. Yoon, Dalton Trans. 2008, 30,

4 Laccase & Lignin Radical-Radical Coupling Reactions Nucleophilic Attack on Quinone Methide Intermediate M. D. Cannatelli, A. J. Ragauskas, Appl. Microbiol. Biotechnol. 2016, 100(20),

5 Laccase-Catalyzed Coupling Chemistry Laccase-Catalyzed Coupling of 1,2-Ethanedithiol with Hydroquinones - Lignin Model Compound Studies Established thiols as good candidates for nucleophilic addition to para-quinones 3,4-(Ethylenedithio)avarone Anti-cancer agent M. D. Cannatelli, A. J. Ragauskas, J. Mol. Catal. B: Enzym. 2015, 119,

6 Hyperbranched Lignin Copolymers Value of a lignin core Renewable Biodegradable Nontoxic Abundant Inexpensive M. D. Cannatelli, A. J. Ragauskas, Appl. Microbiol. Biotechnol. 2017, Submitted, In-Review. 6

7 Hyperbranched Lignin Copolymers Lignin Source, Purification, and Structural Characterization Characterization of hydroxyl group content via 31 P NMR - After derivatization with TMDP Softwood kraft lignin Purification 1) EDTA treatment 2) Soxhlet extraction 3) Dioxane/Water extraction GPC Data M w = 2,350 g/mol PDI: 2.37 Structure mmol/ g lignin COOH p-hydroxy phenyl OH Guaiacyl OH C5 Condensed OH Aliphatic OH Y. Pu, S. Cao, A. J. Ragauskas, Energy Environ. Sci. 2011, 4, M. D. Cannatelli, A. J. Ragauskas, Appl. Microbiol. Biotechnol. 2017, Submitted, In-Review. 7

8 Hyperbranched Lignin Copolymers Proposed Reaction Mechanism Formation of a Copolymer Network 65% of material mass is tris(2-mercaptoethyl)amine based on elemental analysis M. D. Cannatelli, A. J. Ragauskas, Appl. Microbiol. Biotechnol. 2017, Submitted, In-Review. 8

9 Hyperbranched Lignin Copolymers Thermal Analysis TGA DSC Hyperbranched Lignin Copolymer T d ( C) T p ( C) T g ( C) % Mass at 500 C Purified kraft lignin Hyperbranched lignin copolymer M. D. Cannatelli, A. J. Ragauskas, Appl. Microbiol. Biotechnol. 2017, Submitted, In-Review. 9

10 Hyperbranched Lignin Copolymers SEM Surface Characterization Hyperbranched Lignin Copolymer Top View Purified Kraft Lignin Hyperbranched Lignin Copolymer Cross Section M. D. Cannatelli, A. J. Ragauskas, Appl. Microbiol. Biotechnol. 2017, Submitted, In-Review. 10

11 Conclusions & Future Work Laccases are biotechnological tools with great potential to advance sustainability within the chemical industry Fundamental laccase-catalyzed coupling chemistry can be applied to the functionalization of lignin for the synthesis of LCHCs novel route for lignin valorization Material likely exists as a copolymeric network Preliminary results show LCHC material exhibits good thermostability Future studies: - collaborate with materials scientists to develop a novel lignin based biomaterial that s tailored for a particular application (e.g. thermoplastic, resin adhesive) - different monomer selection - addition of a plasticizer into the formulation - may assess adhesive properties 11

12 Acknowledgments 12

13 Circular Economy & Biorefinery Circular Economy Constituents of Woody Biomass Biorefining in the Forest Products Industry W. R. Stahel, Nature 2016, 531, A. J. Ragauskas, G. T. Beckham, M. J. Biddy, R. Chandra, F. Chen et al., Science 2014, 344, A. J. Ragauskas, C. K. Williams, B. H. Davison, G. Britovsek, J. Cairney et al., Science 2006, 311,

14 Lignin Monolignols Irregular, amorphous polymer of oxidatively coupled 4-hydroxyphenylpropanoid units Second most abundant terrestrial biopolymer on Earth In woody biomass, provides mechanical support, water conductive, and antimicrobial properties 50 M tpy produced by global pulp and paper industry (Kai et al., 2016) 2% used for valuable products - dispersants and binders (Lora and Glasser, 2002) Forecasted: 62 M tpy to be produced within the next decade in the US from industrial cellulosic ethanol production (Langholtz et al., 2014) Isolated Kraft Lignin D. Kai, Z. W. Low, S. S. Liow et al., ACS Sustainable Chem. Eng. 2016, 3, J. H. Lora, W. G. Glasser, J. Polym. Environ. 2002, 10, A. J. Ragauskas, G. T. Beckham, M. J. Biddy et al., Science 2014, 344, M. Langholtz, M. Dow ning, R. Graham et al., SAE Int. J. Mater. Manf. 2014, 7, M. D. Cannatelli, A. J. Ragauskas, Appl. Microbiol. Biotechnol. 2016, 100(20),

15 Laccase & Lignocellulosics Laccase-Mediated Functionalization of Lignocellulosic Fibers with Phenols R. P. Chandra, A. J. Ragauskas, Enzyme Microb. Technol. 2002, 30(7), M. D. Cannatelli, A. J. Ragauskas, Chem. Rec. 2017, 17(1),

16 Hyperbranched Lignin Copolymers 1 H NMR Data DMSO-d 6, 50 C Hyperbranched Lignin Copolymer CH 2 Pure Kraft Lignin OCH 3 CH 3 Ar-H Ar-H Phenolic OH OCH 3 Phenolic OH CH 3 CH 2 CH 2 Ar-H SH Phenolic OH Broadening of peaks indicative of polymerization M. D. Cannatelli, A. J. Ragauskas, Appl. Microbiol. Biotechnol. 2017, Submitted, In-Review. 16

17 Hyperbranched Lignin Copolymers 13 C NMR Data DMSO-d 6, 50 C Hyperbranched Lignin Copolymer CH 2 DMSO-d 6 4 Ar-C 4 Ar-C Ar-C C-H Lignin OCH 3 CH 2 CH 3 DEPT-135 Ar-C C-H Lignin OCH 3 DMSO CH 3 CH 2 CH 2 M. D. Cannatelli, A. J. Ragauskas, Appl. Microbiol. Biotechnol. 2017, Submitted, In-Review. 17

18 Hyperbranched Lignin Copolymers 1 H- 13 C HMBC NMR Data DMSO-d 6, 50 C Hyperbranched Lignin Copolymer J 3 coupling between CH 2 protons of tris(2-mercaptoethyl)amine and 4 Ar-C of methylhydroquinone Evidence of covalent linkage between methylhydroquinone and tris(2-mercaptoethyl)amine M. D. Cannatelli, A. J. Ragauskas, Appl. Microbiol. Biotechnol. 2017, Submitted, In-Review. 18