Effect of the ionic aggregation on the crystallisation behavior of poly(ethylene) part of ionomer

Journal of Thermal Analysis and Calorimetry (Impact Factor: 2.21). 01/2003; 73(1):361-380. DOI: 10.1023/A:1025178818103

ABSTRACT The influence of ionic interaction on the melt-crystallization behavior of the ethylene ionomer was studied using modulated
DSC (MDSCTM), wide angle X-ray scattering (XRD) and hot stage microscopy. The kinetics of the crystallization process of the ionomer
was evaluated using isothermal differential scanning calorimetry (iso-DSC). Wide-angle X-ray scattering was used to examine
the d spacing of poly(ethylene) part. The crystallinity of the poly(ethylene) part of ionomer measured from XRD is found to
be 24%, which is comparable to that obtained from MDSCTM. Small-angle X-ray scattering (SAXS) results show that the clusters and multiplets exist in the ionomer, and the cluster
is about 127Ĺ. The kinetics of crystallization process obtained using Avrami equation shows that the crystallization process
is fundamentally similar to poly(ethylene) as it goes through nucleation and propagation stages of the crystals. However,
the morphology of the crystal appears to be different and influenced by clusters (platelike and/or needle-shaped) as evident
from Avrami constant. This is different from the poly(ethylene) (which is spherulitic in nature) due to polar cluster and
hydrophobic PE melt interaction.

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