Catalyst separation in atom transfer radical polymerization

Computer‐Aided Optimization of Conditions for Fast and Controlled ICAR ATRP of n‐Butyl Acrylate

“…Moreover, these authors pointed out that the branching level can be increased by increasing the targeted chain length (TCL), i.e., the initial molar ratio of monomer to ATRP initiator. Even though selection of the appropriate ATRP catalyst enables the synthesis of well-defined polyacrylates and purification methods are available for its removal, [37][38][39][40][41] the amount of catalyst in a normal ATRP process is too high to obtain an economic profitable process. [1,42] Therefore, in the last years, ATRP modified techniques [5,[43][44][45][46][47][48][49][50][51][52][53][54] have been developed in which a low catalyst concentration (ppm level with respect to monomer) is employed.…”

Free-Radical Graft Polymerization onto Starch as a Tool to Tune Properties in Relation to Potential Applications. A Review

“…Catalysts need to be removed from the polymers through various adsorption and extraction techniques [34]. They need to be removed since catalyst-ligand residue is not wanted in the final product, as it induces aging, colors and may add toxic aspects [39], especially when heavy metals, typically Cu(I), would remain in the product. These removals have been demonstrated on a laboratory scale, yet would be technically difficult on an industrial level resulting in expensive products.…”

“…This makes the method more suitable for niche markets, where there are high sales prices [34]. It is also to be considered that ATRP is not compatible with monomers containing certain functional groups, such as carboxylic acids, amines, ketones and certain ionic groups [39], that could deactivate the catalyst. This problem can sometimes be avoided using protection chemistry, but constitutes of course another severe limitation of the method.…”

Surface‐initiated living radical polymerization of self‐assembling L‐phenylalanine‐derived monomer from silica for RP‐HPLC application

“…The flask was then placed in an oil bath with a preset temperature of 90 8C and rotation with slow velocity was maintained for 24 h. The reaction mixture was let to cool at room temperature, filtered and washed with hot toluene, hot chloroform, and methanol repeatedly. For the separation of the remaining catalyst, 30 particles were placed to a round-bottomed flask, suspended in the mixture of methanol and aqueous solution of K 2 EDTA (0.25 M), and then the flask was rotated at 40 8C for 6 h. After filtration, silica particles were washed with water, methanol, and diethyl ether and dried under vacuum, and then were ready for packing in stainless steel column (250 mm  4.6 mm i.d. ).…”