Storage modulus plastics viscosity

Figure 13.13 Reduced storage modulus G and dynamic viscosity rj = G /w as functions of reduced frequency uto) for a cylinder-forming polystyrene-polybutadiene-polystyrene triblock copolymer with block molecular weights of 7000-43,000-7000. The curves are time-temperature-shifted to a reference temperature of 138°C the open symbols were obtained in the low-temperature ordered state the closed symbols were obtained in the high-temperature disordered state. (From Gouinlock and Porter 1977, reprinted with permission from the Society of Plastics Engineers.)...

In paste processing, particle size distribution influences the properties of paste. The amount of free plasticizer in the total amount of plasticizer depends on the particle size distribution of the PVC resin. This is related to packing density, which is improved by bimodal particle size distribution (combination of smaller and larger particles) in which smaller particles fill interstices between the larger partieles. The broad partiele size distribution was found to cause pseudoplastic behavior of PVC pastes. The dynamic viscosity and storage modulus depend on particle size distribution. ... 

Parallel to the study of Yu et al. (2009), a bionanocomposite based on glycerol plasticized-pea starch containing ZnO-NP stabilized by soluble starch as filler, was developed by Ma et al. (2009). In this work, the authors showed that the incorporation of this nanofiller led to improvements in the pasting viscosity, storage modulus, glass transition temperature and UV absorbance. In the same way of Yu et al. (2009), the authors attributed the results to the interaction between ZnO-NP and starch matrix. Soluble starch played an important role in the stabilization of the filler and in the fabrication of starch/ZnO-NP composites. The strong interaction between the filler and the matrix contributed to the improvement in the bionanocomposite properties. 

Figure 5.41. Increase in storage modulus (which parallels the rise in viscosity) from the onset of reaction for a supported sample (resin coated onto an inert substrate) of an epoxy resin. Curve (a) is the isothermal storage modulus-cure time plot curve (b) shows loss modulus. The storage modulus rises in two steps, the first due to gelation and the second to vitrification, and then levels off at a high value characteristic of the glassy state. The loss modulus peak indicates the time to vitrify. High performance epoxy, cure at 155 °C (from Lee and Goldfarb, 1981a, b with permission of the Society of Plastics Engineers).

Figure 8.6 Effect of filler concentration on the complex viscosity and storage modulus variation with frequency for alumina-filled low density polyethylene. (Reprinted from Ref. 44 with kind permission from Society of Plastics Engineers Inc., Connecticut, USA.)...

With dynamic testing, the processed plastic s elastic modulus (relating to energy storage) and loss modulus (relative measure of a damping ability) are determined. Steady testing provides information about creep and recovery, viscosity, rate dependence, etc. 

---