Permeability property of Nylon 6 nanocomposite membranes with various clay minerals

Nylon 6/clay nanocomposites of various clay minerals with different cation exchange capacity (CEC) were prepared by in situ polymerization method and properties like mechanical, thermal and gas permeability were compared with respect to pure nylon 6 (N6) polymer. The functional groups of clay and "-caprolactam (CPL)/clay mixture are detected by using Fourier transform infrared (FTIR) spectroscopy. Wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM) techniques were employed to study the morphology of the nanocomposite material. The intercalated or exfoliated morphology of the nanocomposites only depends on the type of clay, not on the CEC. The thermal property of Nylon 6/clay nanocomposites were examined by using differential scanning calorimetry (DSC) which indicates that the exfoliated nanocomposites exhibit better thermal properties. The CO2 gas barrier property measured by gas permeability analyzer (GPA) confirms that better dispersion of clay in the polymer matrices provides much higher gas barrier property.

Fig. 10. Permeability as a function of storage time for (a) N6, (b) N6/CL-42, (c) N6/CL-114, (d) N6/CL-112, (e) N6/CL-120 and (f) N6/CL-88. In this work, we have used pure clay to synthesize the Nylon 6/clay nanocomposites by in situ polymerization reaction without addition Table 2 Gas permeability (CO2) of pure N6 and N6/clay nanocomposites N6 Loading (phr) Aspect ratio Dispersion Film thickness Gas permeation amount after 60 min (mL) Gas permeability after 60 min (Â10À12) Barrier N6/CL-42 N6/CL-88 N6/CL-112 N6/CL-114 N6/CL-120 6.4 ~100 E&I 5.89 ~100 E 1.01 ~150 E 1.42 ~250 I 4.14 ~150 E 1.11 7.53 6.30 0.86 1.21 4.43 1.07 Barriers ¼ [V (cm3) Â L (cm, film thickness)]/[ÁP (cm Hg) Â t (s) Â A (cm2, film area)].