Synthesis of Biobased Oleocarbonates and Their Use in the Production of Thermally Enhanced Nanofibers by Electrospinning
Özet
Thermal management named as the dynamic heat-storage, has attracted more attention in the last decade because of the demand for developed energy conservation as well as improved thermal comfort. Phase change materials (PCMs), as thermally active materials, have a buffering effect against temperature changes. A PCM is capable of absorbing or releasing large amount of heat during phase transitions between two solid states and/or liquid and solid states. Various encapsulating and shape stabilizing methods for PCMs have been developed by researchers and industry prior to their application on the surfaces for reducing their reactivity with the outside environment, decreasing the evaporation and diffusion rates and promoting the ease of handling [1]. Fatty acids, fatty alcohols and their derivatives, obtained from fats and oils, serve as an important raw material for the oleochemical industry, since they are from biomass resources. Recently, fatty acids and their derivatives have attracted attention as potential biobased PCM candidates in consequence of their attractive thermal characteristics [2,3]. With the aim of spreading out the biobased PCMs away from fatty acids and fatty acid derivatives, this study concerns with the synthesis of two oleocarbonates, namely dihexadecyl carbonate and dioctadecyl carbonate, from fatty alcohols through a carbonate interchange reaction, and examines for their potential to be used as potential biobased PCM in dynamic thermal management of various composites such as clothing textiles and building envelopes. In the second part of the study, bicomponent nanofibers of those oleocarbonates have been produced using poly olefins as shell and oleocarbonates as core material by the coaxial electrospinning process. The thermal behaviors of dihexadecyl and dioctadecyl carbonates during heating and successive cooling in DSC analysis are given in Figure 1. The heat capacity of dihexadecyl carbonate was 192.8 Jg-1 between 33.9–47.8 C and of dioctadecyl carbonate was 178.2 Jg-1 at 47.4–51.1 C which were quite remarkable in terms of their contribution to the dynamic thermal management of PCM incorporated products. Electrospun nanofibers, carrying the thermal properties of corresponding oleocarbonate, were highly competitive with other existing strategies of encapsulating and shape-stabilizing PCMs.
