Characterization of hard-segment crystalline phase of poly(ether-block-amide) (PEBAX®) thermoplastic elastomers in the presence of supercritical CO2 and its impact on foams

Publication date: 7 April 2017
Source:Polymer, Volume 114
Author(s): Mohamad Reza Barzegari, Nemat Hossieny, Davoud Jahani, Chul B. Park
The effects of the saturation temperature and high-pressure dissolved CO2 on the crystallization behavior of polyether-block-amide (Pebax^®) containing various amounts of polyamide-12 hard segment were studied. Non-isothermal and isothermal analyses were conducted using differential scanning calorimetry (DSC) to evaluate the crystallization kinetics of Pebax^® samples. Wide angle X-ray diffraction (WAXD) was used to characterize the crystalline morphology of Pebax^® under various conditions. A higher cell density was observed from the foams of the broader distribution of the hard segment length and the hard segment crystalline phase obtained by twin-screw compounding. It appears that the hard-segment crystals are the heterogeneous nucleating sites that govern the nucleation phenomena of Pebax^®. Therefore, the broader distribution of crystalline phase offers better foaming characteristics because of the larger number of nano-/micro-scale heterogeneous nucleation sites.

Graphical abstract

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