Some viscoelastic properties of ABS polymer

Abstract

SynopsisThe discrete relaxation spectrum of an ABS (acrylonitrile-butadiene-styrene) polymer a t 190°C. was calculated by using results from tensile relaxation moduli and the principle of reduced variables. The shift factor was found to conform well to the WLF equation, and the free volume fraction at T, was calculated to be 0.026 in good agreement with the universal value. The values of the thermal expansion coefficient of free volume were calculated to be 9.8 X 10-4 deg.-l and 7.0 X lo-' deg.-l, respectively, from the WLF coefficients and from dilatometric results. The width of the entanglement plateau of the relaxation spectrum was observed to be a factor of approximately 2 larger than that calculated from molecular weights between entanglement couplings determined either from rubber elasticity theory or from an assumed molecular model which di+ counts the presence of the butadiene in the ABS system. By using Pao's theory, flow curves a t 190°C. were calculated both from the discrete relaxation spectrum and from the dynamic modulus.However, the stress values of these curves were found to be about a decade higher than those experimentally determined from capillary flow measurements. Nevertheless, the shapes of the curves are in good agreement, and an explanation is suggested for existing discrepancies. Flow instability, processing variables, and residual strains are discussed in light of the flow curves and the calculated recoverable shear strains.These curves were essentially identical.

ABS Resins: The Relation between Composition and Rheological Behavior

“…Viscosity dependence on temperature agrees with the findings of Scalco et al (8), Zosel (9), and Bergen and Morris (10). The first authors performed tensile stress relaxation experiments on a commercial ABS polymer, and they concluded that the temperature dependence on the viscoelastic behavior of polyblends was quite similar to that of many amorphous homopolymers above their Tg.…”

“…Varying the structure of the elastomer phase changes the properties of the resin. An increase in the elastomer phase induces the following changes in physical properties:(a) in the solid state, blend rigidity decreases while toughness increases; and (b) in the molten state, viscosity increases (J, 2, 3, 4) while the elastic component (defined as extrudate expansion) decreases (5), which agrees with findings for other heterophase systems (3, 6).Relatively little information is available on the rheological behavior of ABS polymers (4, 5,7,8,9,10). Particularly little work of fundamental nature seems to have been done on the relation between ABS rheological properties and their composition, probably because of their complex structure.…”

“…Relatively little information is available on the rheological behavior of ABS polymers (4, 5,7,8,9,10). Particularly little work of fundamental nature seems to have been done on the relation between ABS rheological properties and their composition, probably because of their complex structure.…”

Archives of Metallurgy and Materials

“…As a process parameter, temperature in-fluences mechanical behavior. ABs properties are strongly related to processing and are especially dependent on the dispersal, size, and shape of the elastomers [37][38][39][40][41]. moreover, the GFrP behavioral properties are strongly related to temperature, and static or low-velocity loads [42][43][44][45][46][47].…”