Metal-Free Hyper-Cross-Linked Polymers from Benzyl Methyl Ethers: A Route to Polymerization Catalyst Recycling
L. A. Prince, Patrick Guggenberger, Elena Santini, Freddy Kleitz, Robert T. Woodward
Abstract
New routes to porous materials can help lower production costs, improve sustainability, and broaden design options. Here, we use a selection of organic acids as catalysts in the synthesis of organic hyper-cross-linked polymers from benzyl methyl ether compounds. This approach provides a new route to metal-free porous organic polymers and addresses one of the largest setbacks of hyper-cross-linked polymers by allowing the simple recovery and recycling of a nonmetallic catalyst. By use of p-toluenesulfonic acid, a solid at room temperature, catalyst recovery rates of >80% were easily achieved. The catalyst was then reused as recovered in the further production of hyper-cross-linked polymers. Three rounds of catalyst recycling are demonstrated on two different aromatic systems, with no apparent detriment to the chemical or textural properties of the resulting networks.