Synthesis of ionic block polymers for desalination membranes

Abstract

Copolymer containing 2‐vinylpyridine–trimethylsilyl methacrylate, styrene–2‐vinylpyridine, and styrene–trimethylsilyl methacrylate blocks as well as terpolymers containing the styrene2–vinylpyridine–trimethylsilyl methacrylate blocks were synthesized by initiation of the appropriate monomers sequentially both with butyllithium and sodium. These polymers were subjected to hydrolysis by which the acrylate ester segment is converted to the free acid and to the reaction with methyl iodide, which quaternizes the pyridine segment; finally the hydrolyzed and quaternized polymers were subjected to dehydrohalogenation with external base. The properties of these block polymers and blends of the styrene‐containing block copolymers were examined, especially in regard to their suitability as reverse osmosis desalination membranes.

Double-Hydrophilic Block Copolymers: Synthesis and Application as Novel Surfactants and Crystal Growth Modifiers

“…The first living anionic synthesis of a DHBC was reported for block copolymers obtained from polymerizing trimethylsilyl methacrylate [4,11] or various alkyl methacrylates and acrylates (methyl, isopropyl and tert-butyl), [4,12] respectively, onto living poly (2-vinylpyridine). Polymerization was started with butyllithium in THF at -78 8C or, recently, for 2-vinylpyridine (2VP) and tert-butyl methacrylate (TBMA) under the same conditions with diphenylmethyllithium as the initiator.…”

“…[13] Similar block copolymers but with a P4VP block were also obtained by the anionic polymerization of TBMA and subsequent polymerization of the P4VP block. [14] Esters were hydrolyzed using NaOH (60 8C) or concentrated H 2 SO 4 (30 8C) after quaternizing P2VP in the case of trimethylsilyl methacrylate [11] or hydrolysis with HCl [13,14] yielding a polyampholyte diblock copolymer consisting of a polyacid and a polybase. Whereas the acidic hydrolysis of PMMA was reported in yields a 90%, alkyl methacrylates were quantitatively hydrolyzed using H 2 SO 4 , as well as trimethylsilyl methacrylate using 5% NaOH.…”

Block Copolymer Membranes for Aqueous Solution Applications

“…Charge mosaic is a different kind of charged membrane, which is still in a fundamental stage of development It constitutes a challenging opportunity for block copolymers. These membranes have alternating nanosize domains with opposite charges [9][10][11][12] . This gives them the capability of being more permeable for salt than for small neutral molecules 10,13,14 , as shown in Figure 2.…”

Poly(methacrylic acid-ran-2-vinylpyridine) Statistical Copolymer and Derived Dual pH-Temperature Responsive Block Copolymers by Nitroxide-Mediated Polymerization

“…Later, the uncoupling of the charges was desired to make block copolymers, which led to dramatically different properties in solution. Traditionally, living polymerizations such as ionic [6][7][8][9][10][11] and later group transfer polymerization [12][13][14][15][16] were used to make polymers with active chain ends that would permit the formation of poly(ampholytes) or schizophrenic block copolymers with a controlled sequence length and narrow molecular weight distributions. In the case of charged species, however, this required protecting group chemistry during the synthesis [6,10].…”