Ball-Milling: A Productive, Economical, and Widely Applicable Method for Condensation of Biomass-Derived Aldehydes and Ketones at Mild Temperatures

Abstract

For the first time, ball-milling was introduced as an efficient process for the condensation of biomass-derived cyclopentanone using commercial CaO as a catalyst. Compared with traditional magnetic stirring methods ("heat input" methods), ball-milling is an alternative "energy input" method. CaO dosage, rotation speed, and reaction time were investigated for optimal condition screening, and the ball-milling method could achieve a high yield (98.9%) and a high selectivity (99.2%) under lower energy demand conditions at mild temperature (∼40 °C). Moreover, the power hypothetically needed for dimer per mole (E 2 ) of the ball-milling method was comparable or even lower than that for the magnetic stirring method after our assessment. In addition, we also explored the applicability of the ball-milling method for the condensation of other biomass-derived aldehydes and ketones. Competitive yield was obtained using heterogeneous CaO as a catalyst. Due to the intense stirring in ball-milling, the CaO catalyst was mixed uniformly with reactants, and higher surface area was also obtained due to the decrease of the particle size during the ball-milling method, which may also benefit the reaction and increase the catalytic activity. This way would tally with the concept of green chemistry and economic efficiency, which has the potential for industrial applications.

Study of the effect of different functionalized magnesium hydroxide prepared by mechanochemical method on the flame retardancy and mechanical properties of styrene‐ethylene‐butadiene‐styrene/polypropylene composites

“…According to Figure 2(a), it is noteworthy that the surface contact angles of MH modified at 20 and 60 min are similar, which indicated that the surface modification can finish in 20 min. Figure 2(b) showed that at fixed reaction time of 20 min, the surface contact angle of MH will increase with the increase of OTES silane coupling agent, and its maximum surface contact angle appears when the OTES silane coupling agent is 50 wt%, which indicated that 50 wt% of OTMS silane agent can achieve complete surface modification of MH 40 …”

“…Figure 2(b) showed that at fixed reaction time of 20 min, the surface contact angle of MH will increase with the increase of OTES silane coupling agent, and its maximum surface contact angle appears when the OTES silane coupling agent is 50 wt%, which indicated that 50 wt% of OTMS silane agent can achieve complete surface modification of MH. 40 The curve of TG analysis is shown in Figure 2(c). A gradual weight loss happen before about 300 C, a sharp decline appears between 330 and 415 C, followed by a gentle weight decrease occures between 415 and 700 C. The first weight loss (blue part) is caused by physically adsorbed water.…”

Cyclopentanone Self-Aldol Condensation by Ball-Milling Method: Optimization Using Response Surface Methodology (RSM) and Life Cycle Assessment (LCA)

“…8 It can go through a self-condensation reaction, and dimer (C 10 compound) and trimer (C 15 compound) can be generated with a high yield (80%). 9−11 Various heterogeneous catalysts have been reported in this reaction, including hydrotalcite-based catalysts, 9 solid metal oxides, 10,12 diatomite-stabilized KOH, 11 and metal−organic framework (MOF)-derived catalysts. 13,14 Yang et al used MgAl hydrotalcite and LiAl hydrotalcite to catalyze cyclopentanone self-condensation, and a high yield (>80%) of the dimer was achieved under optimized conditions.…”

“…27 The ballmilling method has the advantages of less pollution, lower temperature required for experiments, and short reaction time. 28 In our previous work, 10 ball-milling was also explored as a productive and economical method for cyclopentanone self-condensation. Under mild temperature (∼40 °C), high yield (98.9%) and selectivity (99.2%) were obtained.…”

“…Therefore, the synthesis of sustainable fuel from biomass-derived compounds has gained constant interest. − Cyclopentanone is a biomass-derived platform molecule that could be generated by the hydrolysis–dehydration of hemicellulose . It can go through a self-condensation reaction, and dimer (C 10 compound) and trimer (C 15 compound) can be generated with a high yield (80%). − Various heterogeneous catalysts have been reported in this reaction, including hydrotalcite-based catalysts, solid metal oxides, , diatomite-stabilized KOH, and metal–organic framework (MOF)-derived catalysts. , Yang et al used MgAl hydrotalcite and LiAl hydrotalcite to catalyze cyclopentanone self-condensation, and a high yield (>80%) of the dimer was achieved under optimized conditions . Deng et al reported a high selectivity (98.1%) of dimer in the presence of MOF-encapsulated phosphotungstic acid catalyst .…”