Degradation particulate filled

While unique properties, such as dimensional stability or increased modulus, are the usual motivation for exploiting particulate filled eomposites, special attention must be paid to other mechanical properties, such as yield and ultimate strength and fracture toughness, since they are often degraded by the presence of fillers [20],... 

Thermal history in particulate-filled degradable composites and foams 275... 

The evaluation of inhalation solutions and solutions for inhalation should include appearance, color, assay, degradation products, pH, sterility, particulate matter, preservative and antioxidant content (if present), net contents (fill weight and volume), weight loss, and extractables or leachables from plastic, elastomeric, and other packaging components. 

As has already been discussed, and will be returned to later, the introduction of a particulate phase may markedly affect the amount of degradation. The usual effect is for degradation to be increased due to increased mechanical work, to chemical interactions at the interface and possibly to deactivation of stabilisers and antioxidants. The effect is most pronounced under conditions (especially high loadings) where viscosities are high, leading to excessive shear forces being developed. Such effects have been reported in filled elastomers [67] and polypropylene [68]. 

Another type of particulate filler considered for study was glass microspheres which, technically, are spherical aluminosilicate particles (less than 0.03 mm in diameter) filled with carbon dioxide and nitrogen [214]. Samples of epoxy resin filled with glass microspheres (10 %) were tested for erosive resistance after UV irradiation and experimental results indicated that the filler particles improved the resistance of the composite. Still, after prolonged exposure, the effect diminished due to the photochemical degradation of the matrix. Therefore, a top UV-protective coating is recommended. 

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