Synthesis and Characterization of Thiol-Ene Networks Derived from Levoglucosenone

Levoglucosenone (LGO), a renewable compound obtained from cellulose biomass, has been utilized to prepare novel monomers bearing alkene functional groups. These monomer derivatives of LGO were subsequently cured via ultraviolet (UV)-initiated radical thiol-ene "click" chemistry with commercially available multifunctional thiols to obtain colourless, optically transparent cross-linked thermosets. The monomers prepared in this work are unique due to utilising the internal double bond of the LGO ring during polymerization as part of the cross-linked network. The thermal and mechanical properties along with the degradation of thermosets containing both ether and ester linkages within the LGO monomers were studied. These thermosets had tensile strengths of 1.3-3.3 MPa, glass transition temperatures between 23.2 and 27.2 degrees C, and good thermal stability of up to 300 degrees C. LGO which can be obtained by the pyrolysis of cellulose is effectively converted into diene form of ether and ester monomers and these can be polymerized via thiol-ene click chemistry to obtain biobased polymers. image