Structural Peculiarities of Inhibited Film Materials

The most commonly used type of inhibited films is produced by joint processing of thermoplastic polymers and highly dispersed Cl powders. When the melting points, as well as the sublimation and thermal destruction temperatures, of the Cl exceed the viscous flow temperature of the thermoplast, the film acquires the structure of a polymer composite filled with solid inhibitor particles [101]. The particles may partially dissolve in the polymer melt and exert a plasticizing effect on the polymer. Introduction of 1-2% of NBA into PE elevates melt flow by 1.5-1.8 times [10]. Aggregation of solid Cl particles may present essential difficulties for their joint processing with polymer melts and result in structural defects or impair the quality of the film as a whole [4]. 

Homogeneous Aims with a structure typical of plasticized polymer materials are obtained from thermoplastic melts containing slight amounts of thermodynamically compatible liquid Cl [103]. 

Microstructures of respectively outer and inner surfaces of the extruded hose Aim and the film produced by thermodiffusive filling of the polymer base 

The outer surface of the hose has a structure characteristic of a solid PE film. This solid layer gradually transforms across the thickness into an inhibited jelly-like layer (see Sect. 2.2.4 and Fig. 2.6b). The inner surface of the hose has a relief with pore openings over which the Cl can be transported from the jelly-like layer volume into the film surface. Accelerated exudation of the liquid phase is attributed to structural and relaxation processes occurring in the gel [49]. 

Structural peculiarities of inhibited polymer films formed by extrusion encapsulation, i.e. stretching of films in a Cl followed by the thermal treatment, have been described elsewhere [4]. The capsules look like cylindrical voids in the polymer bulk filled by a liquid Cl and oriented along the stretching axis. 

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