Reshaping markets for the benefit of energy saving

Energy saving is an important option for preventing emission of greenhouse gases. Furthermore, when energy saving is reducing the spatial and temporal density of energy consumption, it supports a rising market share of renewable energy sources. Last but not the least, energy saving plays a role in reducing the vulnerability for import dependency and supply disruptions. Despite these virtues energy saving and energy efficiency, being typically demand side options, appear to be harder to ‘sell’ than the other options which focus on the supply side. The currently prevailing market-based approach in energy policy initially brought setbacks for energy saving. The introductory article and the selected contributions to this special issue intend to show that markets can and should be shaped to the benefit of the uptake and of the potential of energy saving. To this end, all elements of the energy efficiency delivery context should be addressed in energy-saving policies. Learning, measurement and observation are important tools in this reshaping process. All contributions are based on papers of the European Council for an Energy Efficient Economy 2003 Summer Study.     

EPDM rubber reinforced with titania generated by nonhydrolytic sol‐gel process

EPDM rubber was reinforced with titania in situ generated by using a nonhydrolytic sol‐gel (NHSG) process starting from TiCl₄ as titania precursor and tert‐butanol as oxygen donor. Titania particles in anatase form and with average diameter of 6 nm were synthesized via NHSG route and then the same procedure was adopted in presence of EPDM rubber to obtain composites containing up to 30 wt% of filler. Extraction and equilibrium swelling tests suggested an interfering effect of the NHSG reaction on the vulcanization process of the rubber resulting to a crosslink density which decreased in the presence of titania. Quasi‐static and dynamic‐mechanical characterizations indicated that the presence of titania as rigid filler in both the unvulcanized and vulcanized EPDM matrix led to a significant increase in stiffness and stress at break. The experimental values of modulus were systematically higher than the values predicted by classical equations suggesting an additional stiffening contribution deriving from the molecular interaction between the rubber and the filler. POLYM. ENG. SCI., 54:2544–2552, 2014. © 2013 Society of Plastics Engineers     

Thermal and mechanical properties of LDPE/sisal fiber composites compatibilized with functionalized paraffin waxes

The effect of maleic anhydride‐grafted hard paraffin wax (MA‐g‐wax) and oxidized hard paraffin wax (OxWax), as possible compatibilizers, on the morphology, thermal and mechanical properties of LDPE/sisal fiber composites were examined. The differential scanning calorimetry (DSC) results show that sisal alone did not change the crystallization behavior of LDPE, while the two waxes influenced the crystallization behavior of LDPE in different ways, whether mixed with LDPE alone or in the presence of sisal. The thermal properties seem to be influenced by the fact that the waxes preferably crystallize around the short sisal fibers, and by the fact that the two waxes have different compatibilities with LDPE. The TGA results show an increase in the thermal stability of the blends in the presence of the two waxes, with LDPE/OxWax showing a more significant improvement. The presence of wax, however, reduced the thermal stability of the LDPE/sisal/wax composites. The presence of OxWax and MA‐g‐wax similarly influenced the tensile properties of the composites. Both waxes similarly improved the modulus of the compatibilized composites, but in both cases the tensile strengths were worse, probably because of a fairly weak interaction between LDPE and the respective waxes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Biodegradable Bicomponent Fibers from Renewable Sources: Melt‐Spinning of Poly(lactic acid) and Poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyvalerate)]

PHBV is produced by bacteria as intracellular carbon storage. It is advantageous concerning biocompatibility and biodegradability, but its low crystallization rate hinders the melt‐processing of fibers. This problem can be overcome by combining PHBV with PLA in a core/sheath configuration and introducing a new spin pack concept. The resulting PHBV/PLA bicomponent fibers show an ultimate tensile stress of up to 0.34 GPa and an E‐modulus of up to 7.1 GPa. XRD reveals that PLA alone is responsible for tensile strength. In vitro biocompatibility studies with human fibroblasts reveal good cytocompatibility, making these fibers promising candidates for medical therapeutic approaches.

     

Total Synthesis of (−)‐Doliculide,Structure–Activity Relationship Studies and Its Binding to F‐Actin

Actin, an abundant protein in most eukaryotic cells, is one of the targets in cancer research. Recently, a great deal of attention has been paid to the synthesis and function of actin‐targeting compounds and their use as effective molecular probes in chemical biology. In this study, we have developed an efficient synthesis of (?)‐doliculide, a very potent actin binder with a higher cell‐membrane permeability than phalloidin. Actin polymerization assays with (?)‐doliculide and two analogues on HeLa and BSC‐1 cells, together with a prediction of their binding mode to F‐actin by unbiased computational docking, show that doliculide stabilizes F‐actin in a similar way to jasplakinolide and chondramide C.     

Nanocomposites Based on Polyethylene and Polyhedral Oligomeric Silsesquioxanes, 1 – Microstructure,Thermal and Thermomechanical Properties

Nanocomposites of linear low‐density polyethylene (LLDPE), with three different amounts of polyhedral oligomeric silsesquioxanes (POSS), were prepared through melt‐mixing in a batch‐mixer at 150 °C. The structure of the prepared nanocomposites was studied by X‐ray scattering and optical microscopy. The surface morphology of the nanocomposites was investigated through field‐emission SEM. The thermal properties of the pure LLDPE and nanocomposites were studied by differential scanning calorimeter (DSC). Thermomechanical properties were assessed on a Paar‐Physics MCR501 rheometer using a solid‐state rectangular fixture. Results exhibited a significant improvement in both the storage and loss moduli of the neat LLDPE upon the incorporation of the POSS particles. A substantial improvement in thermal stability was also observed in the high‐temperature region.

     

Kenaf fiber‐reinforced copolyester biocomposites

In this study the morphology and properties of a biodegradable aliphatic–aromatic copolyester mixed with kenaf fiber were investigated. Untreated kenaf fiber, as well as kenaf fiber treated with NaOH, and with NaOH followed by silane coupling agent treatment at various concentrations, were used as fillers in the composites. The biocomposites were prepared by melt‐mixing and a 10 wt% fiber loading was used for all the composites. The properties of the biocomposites were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), tensile properties, environmental scanning electron microscopy (ESEM), and biodegradability. The extent of silane initiated grafting was followed by gel content determination. The presence of fiber and fiber treatment influenced the determined properties in a variety of ways, but the best balance of properties were found for the copolyester mixed with alkali‐treated fiber. This composite showed improved thermal, thermomechanical, and mechanical properties. The introduction of alkali treatment caused increased surface roughness in the fiber, which resulted in mechanical interlocking between the filler and the matrix, while silane treatment slightly reduced the properties. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers