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

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(c-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 c-caprolactone monomer, resulting in poly(e-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(e-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 a n order of magnitude compared to pure poly(c-caprolactone). 0 1995 John Wiley & Sons, Inc.

Poly(η-caprolactone) layered silicate nanocomposites: effect of clay surface modifiers on the melt intercalation process

“…These observations call for some comments. Although PCL nanocomposites cannot be prepared by melt intercalation of preformed PCL chains within montmorillonite modified by the protonated form of 12-dodecanoic acid (C2: Mont-COOH), the in situ intercalative polymerization of ε-caprolactone in the same organophilic clay (C2: Mont-COOH) was successful as already reported by Messersmith and Giannelis (Messersmith et al [13]) and by some of us (Pantoustier et al [12]). It is thus clear that the nature of the ammonium cation (and the presence of functional groups on the alkyl chains) used as organic modifier of the silicate layers and the preparation route (in situ intercalative polymerization or melt intercalation) play a key-role in the success of nanocomposite formation.…”

“…Nanocomposites based on poly(ε-caprolactone) (PCL) have already been prepared by in situ intercalative polymerization of ε-caprolactone in the presence of a protonated ω-amino-acid exchanged montmorillonite (Messersmith et al [13]). Another synthetic pathway has been recently proposed to produce novel segmented PCL-based polyurethane/clay nanocomposites by step-growth polymerization of diphenylmethane diisocyanate, butanediol and preformed polycaprolactone diol (Chen et al [14]).…”

A simple micromechanical approach to predict mechanical behaviour of polypropylene/organoclay nanocomposites based on representative volume element (RVE)

“…Such nanocomposites benefit from the enhancement of mechanical properties such as higher modulus and strength [1,2], good thermal stability [3], fire retardancy [3,4] as well as excellent barrier properties [5] owing to the tortuous pathway in constituent structures. In an ideal situation, two typically categorised morphologies of nanocomposites are formed, which are known as intercalated and exfoliated structures, Fig.…”

Characterization of clay filled poly (butylene terephthalate) nanocomposites prepared by solution blending

“…These superior properties of clay/polymer composite are may be due to the large surface area of clay, ionic bond between polymer and clay, and good dispersion of clay in the matrix [4] . Clay/polymer nanocomposites are commonly prepared by three principal methods, like solution intercalation, in-situ polymerization and melt intercalation [5][6][7][8] . Melt intercalation is the most convenient, versatile, compatible and environmentally favored technique for the preparation of clay/polymer composite [9,10] .…”