Abstract
The interaction between metal chlorides and the porous montmorillonite (Mont) -polyamide complexes (PMPC) has been investigated using chemical analysis, XRD and infrared (IR) techniques.
When reacted with metal chloride (CoCl2, MgCl2) solution, the intersalation of salts into the interlamellar space of PMPC occurred in addition to the ion-exchange. The salts intersalated were removed by repeated washing with water. In the process of washing, the amount of the salts retained in the interlamellar space increased stepwise with the amount of polyamide (R) complexed in the PMPC. When R was more than 1.6∼1.7 polymer units/ (Si4O10), the salts intersalated were almost retained in the interlamellar space even after washing 5 times. Most of the salts retained in the PMPC after washing 5 times was derived from the salts retained in the interlamellar space. The retainment of salts in the interlamellar space was associated with the random mixed layer structure of two- and three-molecular-layer arrangement of the polyamide in the interlayer. It was presumed that the existence of the third layer in the random mixed layer structure which did not interact with the silicate layer enabled the strong interacfion with metal chlorides and the retainment of them in the interlamellar space. The polyamides not-intercalated which exist on the surface of pores adsorbed the metal chlorides little under present experimental conditions, and their contribution to retainment of salts was small.
The IR measurements of PMPC washed thoroughly (ion-exchanged P MPC) and PMPC washed 5times revealed that through the type of interaction metal chlorides were classified into three groups; Agroup (CoCl2, CuCl2, NiCl2), B-group (MgCl2, CaCl2) and C-group (NaCl).
In A-group, the metal ion co-ordinated to the C = 0 of the amide g roups both in the ion-exchanged PMPC and PMPC washed 5 times in the dehydrated sample. This co-ordinated bonding was hindered by the presence of water molecules. In B-group, the hydrated metal ion interacted with the amide group in the case of ion-exchanged PMPC, and the interaction containing the chloride anion was presumed in the case of PMPC washed 5 times. In C-group, the interaction with the amide group occurred little.
