Some of the material in is restricted to members of the community. By logging in, you may be able to gain additional access to certain collections or items. If you have questions about access or logging in, please use the form on the Contact Page.
Lignin is the second most abundant biopolymers and the most sufficient aromatic renewable resource. Because the lignin is biomass (plant)-based, it is intrinsically biodegradable. In the thesis, the biomass-based lignin was covalently linked to another biodegradable polyester, poly(ethylene brassylate) (PEB) which is originated from castor oil. In addition to the biodegradability, lignin used as a hard-segmental component that can provide strong mechanical property of the finally prepared product. The integration of hard lignin and soft PEB controls mechanical properties by changing the ratio between two segments, lignin and PEB. The new lignin-PEB material is synthesized by following three steps: 1) Lignin was chemically functionalized to convert hydroxyl group to carboxylic acid groups by steglich esterification of succinic acid, 2) the PEB was synthesized from ethylene brassylate by strong guanidine base catalyzed ring-opening polymerization. The synthesized linear PEB contains hydroxyl end groups on both terminals. 3) The lignin-based aliphatic polyester was produced by the polycondensation of PEB and carboxylic acid functionalized lignin. The polycondensation is done by using the commonly used industrial catalyst, antimony oxide (Sb2O3) for PET synthesis. Based upon the newly developed synthetic method of lignin-PEB copolymer, the new biodegradable polymer will be used as an alternative clam-nets material in the future.
