5-(Chloromethyl)furfural (CMF) is cheaper than sugars, because it can be obtained from biomass waste. Herein, the stepwise conversion of CMF to 2,5-bis(hydroxymethyl)furan (BHMF) via 5-(hydroxymethyl)furfural (HMF) was demonstrated for the first time. The purified CMF was hydrolyzed in continuous mode followed by extraction with ethyl acetate (EA), resulting in a HMF yield of 70 mol%. The following factors were assessed during continuous hydrogenation of the produced HMF: the presence of EA in the reaction solvent, HMF concentrations of up to 10 wt% in the feed, the mass production of mesoporous Cu-Al 2 O 3 (meso-CuA-kg), the shaping of meso-CuA-kg into cylindrical pellets, and the setup of the catalytic reactor. Through these efforts, the hydrogenation of HMF over meso-CuA-kg could be sustained for 100 h under the above optimized conditions, affording BHMF in 98 % yield. The approach described in this study can greatly contribute to the valueadded transformation of CMF into HMF and BHMF.

Among the traditional dancheong pigments, orpiment and lead white have problems such as toxic properties, unstable supply and demand, and low color stability. Therefore, alternative methods are needed. This study attempted to solve these problems by reducing the amount of orpiment and lead white by mixing other pigments. The specimens were prepared by mixing orpiment with two types of yellow ochre and one each of oyster shell white and white clay. Lead white was mixed with three types of oyster shell white and white clay. Surface changes, chromaticity, and peeling characteristics were observed. When orpiment was mixed with white pigments, the mixture showed a relatively similar to the orpiment color, compared to when mixed with yellow ochre. When orpiment inside the film was discolored, however, the yellow index was reduced by 20 at most, showing a high color difference value. When orpiment was mixed with yellow ochre (5:5), the mixture was observed to have relatively high chromatic stability and durability, compared to when orpiment was solely used. Until the lowest mixing ratio (2:8), showing a similar color to the lead white. Particularly, the more similar the brightness value of white pigments used was to that of lead white, the closer the mixtures became to the chromatic range of lead white. But they showed different aspects of discoloration and peeling, depending on the mixing ratio of media.

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Invited for this month's cover is the group of Prof. Young‐Woong Suh at Hanyang University, Republic of Korea. The cover picture depicts the conceptual design of plastic manufacture starting from 5‐(chloromethyl)furfural (CMF) generated from raw biomass (rice straw in the picture). The processing is to hydrolyze the CMF to 5‐(hydroxymethyl)furfural (HMF) in aqueous medium, followed by catalytic hydrogenation into 2,5‐bis(hydroxymethyl)furan (BHMF). The BHMF can be used as a monomer for plastics including polyurethanes, epoxy resins, and polyesters. More information can be found in the Research Article by Y.‐W. Suh and co‐workers.

The animal glue used as a vehicle in dancheong easily rots, thereby not allowing easy storage and usability. Therefore, the study explored a method of delaying the rate of rotting through a method of adding preservatives to the animal glue, which increases resistance against microorganisms. For the preservative, the study selected the best condition in terms of preservative efficacy out of three conditions (Phenoxyethanol, Phenoxyethanol : Ethylhexylglycerin (9 : 1), alum) through the use of biological experimentation. Consequently, the study found that the exclusive use of phenoxyethanol demonstrated the highest level of preservative effect. The preservative efficacy under this condition was proportional to the mixing concentration of the preservative, and in particular, the initial growth rate of mold was roughly 1.4 to 2 times lower than the condition where no preservatives were added. Based on these results, a material properties evaluation and a weathering test were used to observe the impact of phenoxyethanol on the material properties and the colored layer of the animal glue. Ultimately, the impact of phenoxyethanol on the viscosity, pH of animal glue, and chromaticity of the colored layer was small. Discoloration and flaking characteristic due to degradation was similar to a condition of not applying phenoxyethanol. The study confirmed phenoxyethanol to be stable in term s of the m aterial properties and the colored layer of the anim al glue for up to a m axim um of 20% of the weight of the animal glue. Simultaneously, phenoxyethanol was confirmed to improve the preservative efficacy of the animal glue.