Interfacial tension of PBT/SAN blends by the drop retraction method

Abstract

The aim of this work was to evaluate the interfacial tension from the poly(butylene terephtalate) and poly(styrene-co-acrylonitrile) (PBT/SAN) interface region using the drop retraction method. SAN filaments were sandwiched between two PBT films; the whole system was heated up to 240 °C, in a hot stage coupled to an optical microscope. The rheological parameters of the PBT/SAN system were obtained by parallel plates rheometry. An increase of the interfacial tension with the PBT molecular weight was observed with values between 0.57 and 1.06 mN/m, depending on the molecular weight. Theoretical values were calculated using the geometric-mean and harmonic-mean equations and were found to be similar to the experimental results. Viscosity measurements showed that the higher the SAN/PBT viscosity ratio, the lower the interfacial tension of these blends.

Characterization of the Ultralow Interfacial Tension in Liquid–Liquid Phase Separated Polyelectrolyte Complex Coacervates by the Deformed Drop Retraction Method

“…The model was previously verified by simulation studies 25 and used to measure the interfacial tension of coexisting polymer melts. 16,26 ■ RESULTS Viscoelasticity and Zero-Shear Viscosity. At a zerostress condition, the shape-retraction kinetics of a deformed drop depends on the interfacial tension and the viscous drag in the absence of other relaxation mechanisms.…”

“…However, it may be applicable for viscoelastic liquids with stress relaxation time τ s ≪ τ. The model was previously verified by simulation studies and used to measure the interfacial tension of coexisting polymer melts. , …”

“…The interfacial tension may be determined by additional independent measurements of the coacervate to dilute phase viscosity ratio. The DDR method has broad applicability to immiscible polymer blends, − biopolymers, effects of nanoparticles additives to polymer blends, and isotropic to nematic transition in liquid crystalline polymers . A microfluidics method is also available for applicable systems .…”

Optimized polybutylene terephthalate powders for selective laser beam melting

“…Taking typical material parameters of PBT into account, i.e. a surface tension of the melt of σ = 30.2 mN/m (Ito et al, 2008) and a melt viscosity of η = 452 Pas (Fakirov, 2002), a characteristic sintering time of about 1.5 s is calculated for particles sized a f = 0.5 * x 90,3 (rounded PBT) = 22.9 µm using equation 3, i.e. the residence time chosen (7.7 s) allows for complete rounding.…”