Thermal and bio-disintegration properties of poly(lactic acid)/natural rubber/organoclay nanocomposites

Poly(lactic acid) (PLA) is a bio-based and biodegradable thermoplastic which has attracted widespread interest from both academia and industry over the past few years due to its high potential in replacing petroleum based plastics. PLA not only displays a high modulus and high strength but also presents an inherent brittleness and slow crystallisation rate that currently reduces its range of applications (Auras et al., 2004). In our previous study, we reported the development of a ductile PLA/NR blend by adding 10 wt.% of natural rubber (NR) to the PLA matrix leading to a strong increase of the elongation at break and crystallisation rate of PLA (Bitinis et al., 2011). Moreover, the addition of low amounts of organoclays acted as a compatibilising agent between both polymers, reducing the NR droplet sizes from 1 μm to about 300 nm, through their location at the polymer interface (Fig. 1). The properties of the resulting bionanocomposites, such as mechanical or gas barrier properties, could be tailored depending on the filler nature and blending procedure (Bitinis et al., 2012). Nevertheless, it is also of interest to study the influence of the organoclays over the crystallisation properties of the blend, as well as over its thermal and biodegradation properties.