Regulating intermolecular chain interaction of biopolymer with natural polyol for flexible, optically transparent and thermally conductive hybrids

Natural polymers like cellulose are rich in hydrophilic groups those are able to form intermolecular and intramolecular hydrogen bonding interactions. The regulation of such interactions can be critical for tuning material functionality. In this work, we designed a sustainable hybrid comprising of sodium carboxymethyl cellulose (SCMC) and xylitol, in which the molecular interaction is tuned for significantly enhanced thermal conductivity (TC). With optimized ratio of SCMC and xylitol, enhanced TC of up to 1.75 times of neat SCMC was achieved in addition to excellent flexibility and optical transparency. These enhancements are attributed to the formation of new H-bonds between SCMC and xylitol molecules resulting in formation of homogenously distributed thermal bridges throughout the polymer matrix. The intermolecular interaction in SCMC-xylitol composites elucidates some of the fundamental factors (e.g. H-bond intensity) responsible for promoted phonon transfer in polymeric materials, and at the same time sheds light on the capability of employing biopolymer-polyol based materials for thermal management applications.