Polymer Conformation under Confinement.

Stavros Bollas,Spiros Anastasiadis,Kiriaki Chrissopoulou,Konstantinos Andrikopoulos,George Voyiatzis

doi:10.3390/polym9020073

Abstract

The conformation of polymer chains under confinement is investigated in intercalated polymer/layered silicate nanocomposites. Hydrophilic poly(ethylene oxide)/sodium montmorillonite, PEO/Na+-MMT, hybrids were prepared utilizing melt intercalation with compositions where the polymer chains are mostly within the ~1 nm galleries of the inorganic material. The polymer chains are completely amorphous in all compositions even at temperatures where the bulk polymer is highly crystalline. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) is utilized to investigate the conformation of the polymer chains over a broad range of temperatures from below to much higher than the bulk polymer melting temperature. A systematic increase of the gauche conformation relatively to the trans is found with decreasing polymer content both for the C–C and the C–O bonds that exist along the PEO backbone indicating that the severe confinement and the proximity to the inorganic surfaces results in a more disordered state of the polymer.

Highlights

The growing use of polymers results in a continuous demand of improving their properties as well as of understanding the mechanisms, which rule their response
Of particular interest among the different organic/inorganic nanohybrids are polymer/layered silicate nanocomposites, which constitute a class of materials that has attracted growing scientific and technological interest over the last decades due to their unique properties, which make them candidates for a number of potential applications [18,19,20,21,22,23,24,25,26,27,28,29]
We investigate in detail the chain conformation in hydrophilic poly(ethylene oxide)/sodium-montmorilonite nanocomposites

Summary

Introduction

The growing use of polymers results in a continuous demand of improving their properties as well as of understanding the mechanisms, which rule their response. One way to achieve these aspects is the development of polymer nanohybrids, which, by combining organic and inorganic components, can improve the properties of the initial materials and can provide alternative ways for the understanding of the behavior in a variety of scientific fields [1,2,3,4,5,6,7,8,9,10,11,12,13,14] The properties of such nanohybrids depend on the properties of their individual components but mainly on their morphology and interfacial characteristics [15,16,17]. Polymer chains penetrate within the interlayer galleries of the inorganic material forming a highly ordered arrangement of alternating organic and inorganic layers; this is Polymers 2017, 9, 73; doi:10.3390/polym9020073 www.mdpi.com/journal/polymers

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Discussion

Conclusion