(370d) Process Intensification of the Synthesis of Poly(vinyl butyral) Using a Micro-Structured Chemical System

In this work, we established a novel micro-structured chemical system to intensify the synthesis process of poly(vinyl butyral) (PVB) based on the mixing enhancement principle of poly(vinyl alcohol) (PVA) – n-butanal aqueous solution with hydrochloric acid. Because of the high mixing performance, higher temperature (30~60°C) with much higher reaction rate was applied. By studying the parameters of flow rate, temperature, feeding ratios of n-butanal and H⁺ to the hydroxyl groups in PVA, the apparent butyral group content in PVB reached to more than 60% with a residence time within 1 min in microreactor, and reached to 75% with one more hour’s aging time, much shorter than the conventional 8 ~ 10 hours in low temperature batch reactors. The size of primary PVB particle was smaller than 10 μm, which might reduce the time and water consumption in the post washing process. This work provides a good example for operating reactions between macromolecules and small molecules in microreactor system.