Staining methods ebonite method

The study of phase size and compatibility requires that the different phases be observed, distinct from one another, and that there is minimum distortion in the polymers. However, multiphase polymers often cannot be stained or sectioned uniformly. There are composite structures that are combinations of soft rubbers, coatings and oriented fibers which caimot be stained with a single staining agent and the sections may be deformed or distorted, limiting both observation and interpretation. The ebonite method was developed by Smith and Andries [111] to stain and uniformly harden polymers. 

A modified ebonite method was developed [113] to study the interfaces associated with polymer tire cords. Tire cords composed of PET, rayon or nylon fibers are generally bonded to rubber with a resorcinol-formaldehyde-latex (RFL) adhesive. The nature of the interfaces are of interest in tire cord studies. OSO4 may be used to stain and harden the RFL, but the soft rubber is not affected by this treatment, and, in fact, it forms a barrier to stain penetration. The ebonite reaction hardens the rubber and hardens and stains the RFL while maintaining the geometrical integrity of the composite. 

---