Thermodynamics Research Center / ThermoML | Thermochimica Acta

ABSTRACT

Three novel bis 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) phosphonates includ-ing ethyl-bridged (DOPO2-ethyl), phenethyl-bridged (DOPO2-phenethyl), naphthalene-bridged (DOPO2-naphthalene) were synthesized and characterized. Thermal degradation properties of the synthesizedcompound alone and poly(lactic acid) (PLA) composites based on these compounds were examinedby thermogravimetric. The kinetic parameters of PLA composites were calculated through Flynn-Wall-Ozawa method. The results showed that these derivatives had excellent thermal stability with startdecomposition temperature above 360 degC, and with the increasing of aromatic rings in the molecularstructure, the content of phosphaphenanthrene group remained in the condensed residues displayedan increase trend. Moreover, the thermal degradation behavior of PLA composites displayed significantdissimilarity to that of pure PLA. In addition, the activation energy increased from 51 kJ/mol of purePLA to 141, 93, and 166 kJ/mol of PLA/DOPO2-ethyl, PLA/DOPO2-phenethyl, PLA/DOPO2-naphthalene,respectively, at 5% conversion, and these values increased to 179, 131 and 166 kJ/mol at 50% conversion,respectively.