Combining renewable gum rosin and lignin: Towards hydrophobic polymer composites by controlled polymerization |
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Authors: | Jifu Wang Kejian Yao Andrew L Korich Shigeng Li Shuguo Ma Harry J Ploehn Peter M Iovine Chunpeng Wang Fuxiang Chu Chuanbing Tang |
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Institution: | 1. Department of Chemistry and Biochemistry and Nanocenter, University of South Carolina, Columbia, South Carolina 29208;2. Institute of Chemical Industry of Forestry Products, Chinese Academy of Forestry, Nanjing 210042, China;3. Department of Chemistry and Biochemistry, University of San Diego, 5998 Alcala Park, San Diego, California 92110;4. Department of Chemical Engineering, University of South Carolina, Columbia, South Carolina 29208 |
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Abstract: | Rosin polymer–grafted lignin composites were prepared via “grafting from” atom transfer radical polymerization (ATRP) with the aid of 2‐bromoisobutyryl ester‐modified lignin as macroinitiators. Three different monomers derived from dehydroabietic acid (DA) were used for execution of grafting from ATRP, while DA was separately attached onto lignin by a simple esterification reaction. Kinetic studies indicated controlled and “living” characteristics of all monomer polymerizations. Thermal studies indicated that rosin polymer–grafted lignin composites exhibited glass transition temperatures in a broad temperature range from ~20 to 100°C. The grafting of both DA and rosin polymers significantly enhanced hydrophobicity of lignin. Static contact angle measurement of water droplets showed ~90° for all these rosin modified lignin composites. X‐ray photoelectron spectroscopy demonstrated that the surface of rosin–lignin composites was dominated with chemical compositions originating from the hydrocarbon rich rosin moiety. The impartation of hydrophobicity of rosin into lignin provided excellent water resistance of this class of renewable polymers, as all rosin‐modified lignin composites showed water uptake below 1.0 wt %. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 |
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Keywords: | atom transfer radical polymerization (ATRP) composites hydrophobicity lignin renewable resources rosin |
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