Poly(ε-caprolactone) nanocomposites with layered double hydroxides modified by in situ grafting polymerization: Structure characterization and barrier properties

The synthesis of multimetallic layered double hydroxides-g-poly(epsilon-caprolactone) (LDHs-g-PCL) was explored by in situ ring-opening polymerization, considering layered clay's improvement on barrier properties in polymer films. LDHs/PCL nanocomposites were prepared by blending LDHs-g-PCL and pure PCL via solution casting method. With incorporation of as low as 0.2 wt % of LDHs, LDHs/PCL nanocomposites exhibited excellent mechanical performance with tensile strength and elongation at break over 45 MPa and 837%, respectively. Compared with pure PCL, the O-2 permeability of LDHs/PCL nanocomposites decreased by nearly 78% as LDHs content increased up to 1 wt %. It was revealed that the key parameter to improve the barrier properties is not only the high aspect ratio of layered clays but also the specific interactions that they develop in the polymers matrix. Due to the merits of its biodegradation and physical properties, LDHs/PCL nanocomposites could be potential materials applied in packaging industry widely. (C) 2017 Wiley Periodicals, Inc.