The performance of solar-thermal conversion systems can be improved by incorporation of encapsulated phase change materials. In this study, for the first time, Crodatherm^TM 60 as a phase change material (PCM) was successfully encapsulated within polyurea as the shell supporting material. While preparing the slurry samples, graphite nanoplatelet (GNP) sheets were also incorporated to enhance the thermal and photothermal properties of the prepared materials. The morphology and chemical properties of these capsules were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectrum, respectively. The results show the spherical-like and core-shell structure of capsules with an average diameter size of 3.34 μm. No chemical interaction was observed between the core and the supporting materials. The thermal characteristics of the microencapsulated PCMs (MEPCMs), analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), indicate that the prepared samples with 0.1 weight percentage of GNP possess the latent heat of 95.5 J/g at the phase transition temperature of about 64 °C. Analyzing the rheological properties of the prepared slurry with 16 wt % of MEPCMs proves that the prepared material meet the requirements given by the heat transfer applications. The thermal storage capacity, good thermal stability, and improved photothermal performance of the prepared material make it a potential candidate for using in direct absorption solar thermal applications.

ABS is widely used as engineering plastic, but extensive use generates a significant amount of waste which is difficult to recycle due to material's complex composition. Physical recycling of ABS using TNO Möbius dissolution technique has been used here to separate pure SAN polymer, from PBR, and other substances. Relationships between properties and composition of the original materials were investigated as a starting point for evaluation of the effects of recycling on the quality of recycled materials. Three ABS materials were used in the recycling process to produce pure SAN polymers. The recycled SANs were then melt-blended with fresh masterbatch. The final ABS ma-terials had the same composition which allowed to investigate whether SAN recycled from different sources causes differences in properties of the final ABS materials. All properties of ABS materials made with recycled SAN are similar regardless of the source of SAN. Substances were quantified in the original ABS materials and in SAN polymers obtained by the recycling process. The substances were largely removed from all materials except one. The main conclusions from this study are that SAN polymer obtained by physical recycling from different sources does not affect properties of the final ABS material and the TNO process successfully separates SAN from other substances.

Acrylonitrile butadiene styrene (ABS) is widely used as an engineering plastic, but its extensive use generates a significant amount of waste that is difficult to recycle due to the material’s complex composition. In this study, the physical recycling of ABS using the dissolution technique has been employed to separate the pure copolymer of styrene and acrylonitrile (SAN) from polybutadiene rubber (PBR) and other substances. The relationships between the properties and composition of the original ABS materials were investigated as a starting point and for reference values to evaluate the effects of recycling on the quality and safety of recycled materials. Three different ABS materials were used in the recycling process from which pure SAN polymers were produced. The recycled SANs were then melt-blended with fresh masterbatch. The final ABS materials had the same composition, which facilitated investigation of whether the use of SAN recycled from different sources results in any differences in the properties of the final ABS material. The results showed that all the properties of ABS materials made with recycled SAN are similar regardless of the source of SAN. Several chemical substances were quantified in the original ABS materials and in SAN polymers obtained through the recycling process. The substances were largely removed from all materials except one. The main conclusions from this study are that the quality of ABS materials made with recycled SAN is at the same level as that of virgin ABS and is independent of the source from which SAN comes. This study has also shown that chemical safety is satisfactory because the physical recycling process is able to remove most of the substances that were present in the original ABS materials.