Preparation and thermal properties of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/aluminum-containing layered double hydroxides nanocomposites

In this study, the nanocomposites based on poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3,4)HB) and three kinds of aluminum-containing layered double hydroxides (LDHs) were prepared via melting intercalation. The thermal stability, thermal combustion and thermomechanical properties for these systems were systematically investigated. Both x-ray diffractometry and transmission electron microscopy analyses for P(3,4)HB/LDH system confirm that P(3,4)HB/magnesium-aluminum (MgAl) system has a main exfoliated microstructure and P(3,4)HB/ZnAl system has an intercalated or partially exfoliated microstructure, while P(3,4)HB/NiAl system has an intercalated or phase separated microstructure. The microscale combustion calorimetry results show that the peak of heat release rate for P(3,4)HB/LDH systems, as an important parameter for the assessment of fire hazard of materials, is significantly reduced with the addition of LDHs. The storage modulus of three systems with small amount of LDHs measured by dynamic mechanical analysis is remarkably enhanced. The increment in the storage modulus of P(3,4)HB/LDH nanocomposites will increase with the increase in the atomic number of M2+ of LDHs.