The Modulus of Multicomponent Polymeric Materials

Qualitatively, the modulus of polymer blends and composites is expected to be intermediate between the modulus of the materials involved. Quantitatively, the picture is more complex, depending on phase morphology and continuity. The Takayanagi models (Section 10.1.2.3) explore the basic methods of calculating not only the modulus, but many other viscoelastic quantities. While the original models were developed with glassy and rubbery polymers in mind, they are quite general and useful for composite systems as well. 

thermosets such as epoxy resins are frequently reinforced with either glass fibers or carbon fibers (also known as graphite fibers) (8,9). As an example calculation, the modulus of a unidirectional glass fiber-epoxy composite will be calculated in both the longitudinal and transverse directions. The properties of the materials are 

This value is much lower than the longitudinal values. The experimental values (8), of the Takayanagi model, and computer-calculated values (9) are compared in Table 13.5. 

Thus the Takayanagi longitudinal modulus prediction is seen to be nearly correct, but the Takayanagi transverse modulus prediction is seen to be low. 

However, the Takayanagi model is intended for use when the discontinuous phase portions are separated. At 62% fiber, the fibers have to be almost or actually touching in many places. 

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THE MODULUS OF MULTICOMPONENT POLYMERIC MATERIALS 701 Integrated composite analyzer (ICAN)... 

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