열적 특성이 향상된 Poly(lactic acid)/Halloysite nanotube composites의 제조 및 특성 연구

Abstract

Poly (lactic acid) (PLA) is one of the representative biodegradable polymers which can be generally manufactured by polymerizing the lactic acid (LA) obtained from agricultural crops such as corn and potato. PLA is widely used in various applications such as packaging, electronics, biological and medical applications due to its high resistance to heat shrinkage and excellent physical properties. However, the applications of PLA has been limited due to low thermal stability and elongation etc. In this study, PLA was synthesized by ring-opening polymerization. And PLA/halloysite nanotube (HNT) nanocomposite was prepared by using HNT, which is aluminosilicate mineral, to improve the thermal properties of PLA. PLA/HNT nanocomposites were prepared by ring-opening polymerization or kneader blending, and characterization studies were performed according to the amount of HNT. The PLA polymerization was confirmed by the characteristic band of the Fourier transform infrared spectroscopy (FT-IR) spectra. The thermal properties of the composites were investigated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). As the content of HNT increases, the temperature at which mass reduction proceeds, that is, the thermal stability, tends to increase. The mechanical properties of the composites thus obtained were investigated. As a result, the mechanical properties of the composites were improved as HNT content increase.