Characterization of NCH

The relationship between the interlayer distance ds (d-spacing) in the silicate layers and the amount of 12-Mt in the NCH was analyzed as follows. If the ratio 

5 Relationship between ratio R of nylon 6/12-Mt and basal spacings (ds). Solid line observed values, dotted line calculated from Equation (1.2). 

In this equation, d(, is the observed interlayer distance, ds is the interlayer distance calculated using Equation (1.2), and the thickness of a silicate layer is taken to be 1. 

The pi value of NCH15 was 73.0% and that of NCH70 was 97.6%, i.e., the pi value increased as the amount of 12-Mt increased. These results show that 12-Mt initiated e-caprolactam polymerization and that most of the nylon was polymerized between the 12-Mt layers. 

If the montmorillonite content is Wm (wt.%), the amount Cnh3+ (mol/g) of ammonium groups in NCH can be calculated based on the equivalence between the montmorillonite s cation exchange capacity (CEC) and the amount of ammonium groups, as shown in Equation (1.4)  

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