Investigation of the Reaction Kinetics of Poly(butylene terephthalate) and Epoxide Chain Extender

Polyesters, such as poly (butylene terephthalate) (PBT), owe a rather low melt strength, which is considered not beneficial for foaming. To overcome this issue, typical attempt the incorporation of chemical modifications—so-called chain extenders (CE)—in reactive extrusion process. In study, reaction kinetic variables are investigated depending on material and process parameters. For purpose, different series experiments performed with varying PBT molecular weights commonly used CE, Joncryl ADR4468, micro compounder. The screw force recorded analyzed using an Avrami Arrhenius plot. First, amount CE systematically varied. study course in more detail, stopped measurements (10, 30, 60, 90 s after complete filling). Gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FT-IR), Raman spectra recorded. second series, effect processing temperatures between 250 270 °C investigated, finally, third average weight It could be shown that activation energy seems to dependent initial weight; lower result energy.