Thermal Degradation Behavior and Gas Phase Flame-Retardant Mechanism of Polylactide/PCPP Blends

摘要

The thermal degradation behavior of the blend based on polylactide (PLA) and poly(1,2-propanediol 2-carboxyethyl phenyl phosphinate) (PCPP) was investigated by the thermogravimetric analysis (TGA). Thermal degradation activation energies (E_a) of neat PLA and PLA/15 PCPP blend were calculated via the Flynn–Wall–Ozawa method. The E_a of the blends increased with the addition of PCPP increasing when the conversion was higher than 10. In addition, the appropriate conversion models for the thermal degradation process of PLA and PLA/15 PCPP were studied via the Criado method. At the same time, the main gaseous decomposition products of PLA and its blend were identified by TGA/infrared spectrometry (TGA–FTIR) analysis. And it revealed that the PCPP improved the flame-retardant property of PLA via altering the release of the flammable gas and nonflammable gas. Moreover, the PCPP improved the flame-retardant property of PLA by inhibiting exothermic oxidation reactions in the combustion, which was further proved by pyrolysis–gas chromatography–mass spectrometry analysis.