Effects of attapulgite on crystallization and thermal stability properties of poly (lactic acid)

Nano attapulgite/poly(lactic acid) (ATT/PLA) composites were prepared by melting blend with 1%, 3% and 5% mass fraction of attapulgite respectively. Effects of attapulgite on the crystallization and thermal stability properties of PLA were studied in this paper. Results show that the ATT has good compatibility with PLA when its content is less than 3%, but ATT forms in bundles when the content is more than 5%. FTIR results show there are strong interaction between ATT and PLA matrix. ATT has the function of nucleating agent and leads to accelerate the crystalline rate of PLA. In addition, the cold crystallization peaks of various nano ATT/PLA composites shift from 114.4 ℃ to 103 ℃. The crystallization rate of nano ATT/PLA composites is faster than that of the neat PLA, which indicates that ATT is one of the efficient nucleating agent for PLA. ATT can accelerate the crystalline rate of PLA and decrease the size of the spherulite with the increasing of the ATT content loading. The thermal decomposition temperature of nano ATT/PLA composites is about 11 ℃ higher than that of the neat PLA, when the ATT content is 3%. The reason is due to the forming of higher density network between PLA and ATT, which suppresses the degradation of PLA.