Synthesis and barrier properties of poly(ε‐caprolactone)‐layered silicate nanocomposites

TLDR

The protonated amino‑acid derivative of mica‑type silicate promotes delamination and initiates ring‑opening polymerization of ε‑caprolactone, yielding poly(ε‑caprolactone) chains ionically bound to the silicate layers. The polymer chains can be released by reverse ion‑exchange and are spectroscopically identical to pure poly(ε‑caprolactone), while thick films of the nanocomposite show a linear reduction in water‑vapor permeability with silicate content, with 4.8 vol % silicate lowering permeability by nearly an order of magnitude. © 1995 John Wiley & Sons, Inc.

Abstract

Abstract A new polymer‐ceramic nanocomposite has been synthesized consisting of well‐dispersed, two‐dimensional layers of an organically modified mica‐type silicate (MTS) within a degradable poly(ε‐caprolactone) matrix. A protonated amino acid derivative of MTS was used to promote delamination/dispersion of the host layers and initiate ring‐opening polymerization of ε‐caprolactone monomer, resulting in poly(ε‐caprolactone) chains that are ionically bound to the silicate layers. The polymer chains can be released from the silicate surface by a reverse ion‐exchange reaction and were shown to be spectroscopically similar to pure poly(ε‐caprolactone). Thick films of the polymer nanocomposite exhibit a significant reduction in water vapor permeability that shows a linear dependence on silicate content. The permeability of nanocomposite containing as low as 4.8% silicate by volume was reduced by nearly an order of magnitude compared to pure poly(ε‐caprolactone). © 1995 John Wiley & Sons, Inc.