Abstract
Three esters of Hinoki cypress (Chamaecyparis obtusa)-lignophenol(p-cresol type, HCLC), acetate (HCLCAc), benzoate (HCLCPh) and oxyallylcarbonate (HCLCalloc), were investigated using FT-IR, 1H NMR, SEC, TGA, TMA and DSC. These esters demonstrated larger Mw than lignophenol (LP) due to electrostatic interaction and inter- and intra-molecular interactions of ester side chains. Both TGA and TMA showed higher thermal stability and good plasticity at a lower temperature than HCLC. The thermal stability of esters were evaluated using Ozawa plots of the TGA analysis data. Improvement of these properties depends on both ester linkages and side chains of esters. Moreover, DSC showed clear Tg on the first run without exo-thermal peaks, that means no thermal degradation. These results show that it is possible to control the properties of lignophenol esters and to investigate unknown thermal properties of main chains in HCLC based on native lignin.
