Chemical processes assisted by microwave heating are attractive energy-saving processes. We applied microwave heating to the polycondensation of lactic acid, which conventionally is known as a high-energy-consuming process. We herein studied the microwaveassisted reaction at scales ranging from several tens of milliliters to several tens of liters. Poly(lactic acid) polymers with average molecular weights exceeding 10,000 were obtained after 5 h of microwave heating. Analysis of the consumed microwave power also showed that the energy used by the polycondensation per mole of substrate was saved by scaling up the reaction.
The layered material Rb x Mn x Ti 2-x O 4 (x ) 0.75) was pillared with silica. The Rb ions were first exchanged with n-alkylammonium ions (C n H 2n+1 NH 3 , n ) 6-18) to separate the interlayer space of the titanate, and then tetraethoxysilane was hydrolyzed between the layers. Burning off the organic parts resulted in silica pillared microporous solids with a surface area as large as 500-800 m 2 /g. The porous structure was stable up to 600 °C. Adsorption-desorption isotherms for various vapors, such as water, methanol, toluene, and mesitylene, were measured, which suggested that the porous structure formed between the layers was very similar to those of zeolites and uniform without mesopores. The pores showed hydrophobic properties. Their size was on the order of that of mesitylene.
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