Swelling and mechanical properties of thermoresponsive/hydrophilic conetworks with crosslinked domain structures prepared from various triblock precursors

Abstract

Thermoresponsive conetworks with crosslinked domain structures were designed by the crosslinking of triblock polymers for responsive gel functioning without external water.

Nanoconfined Crosslinked Poly(ionic liquid)s with Unprecedented Selective Swelling Properties Obtained by Alkylation in Nanophase-Separated Poly(1-vinylimidazole)-l-poly(tetrahydrofuran) Conetworks

“…Nanoconfined material structures, including polymers as well, due to the wide range of unique structural features, properties, and effects arising under nanocompartmentalized conditions, have created significant worldwide interest over the last couple of years (see e.g., references [ 1 , 2 , 3 , 4 , 5 , 6 ] and references therein). The recently emerged polymer conetworks, especially amphiphilic conetworks (APCNs), composed of covalently or supramolecularly bonded, otherwise immiscible, hydrophilic and hydrophobic polymer chains, belong to such nanophase-separated materials with mutually nanoconfined macromolecular components [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. Considering that polymers containing imidazole rings, which also play a pivotal role in the major biopolymers and compounds of living organisms, such as DNA, RNA, proteins, enzymes, hormones, vitamins, etc., provide various advantageous properties, like water solubility, strong metal ion coordinating ability, protonation, and alkylation possibilities, we have recently explored the synthesis, nanophasic structure, and properties of poly(1-vinylimidazole)- l -poly(tetrahydrofuran) (PVIm- l -PTHF) and poly(1-vinylimidazole)- l -poly(propylene...…”

Mechanical response and equilibrium swelling of thermoresponsive copolymer hydrogels

“…Applications of TR hydrogels in the biomedical field 6 for DNA and protein electrophoretic separation 7 and the manufacture of temperature‐triggered actuators 8 require modulation of the volume phase transition temperature T c in a rather wide interval. The preparation of TR gels with tunable volume phase transition temperatures has been analysed in a number of studies 9–13 . It is found that (i) T c is practically unaffected by molar fractions of monomers and crosslinkers and preparation conditions (the temperature at which crosslinking polymerization is performed and the solvent for synthesis), (ii) it changes weakly with addition of polymer chains into a pre‐gel solution to form semi‐interpenetrating polymer networks, and (iii) T c changes pronouncedly when TR monomers are mixed with relatively small amounts of monomers whose hydrophilicity differs from that of the basic monomers.…”

Crosslinker-Based Regulation of Swelling Behavior of Poly(N-isopropylacrylamide) Gels in a Post-Polymerization Crosslinking System

“…For example, simple mixing two kinds of poly(acrylamide derivative) prepolymers with different solubility afforded an amphiphilic co-network structure showing unique thermoresponsive swelling behavior [24]. In addition, a designed amphiphilic structure with crosslinked domains can be obtained by using the triblock prepolymer having reactive sites in the outer blocks, and these gels turned out to exhibit large and sharp volume changes and unique mechanical properties [25,26]. Scheme 1.…”

“…This strong solvent effect on the reaction leads to the difficulty in the understanding the effect of a crosslinkers on gel properties even at simply changing the alkyl chain length of a crosslinker, because the solubility of a crosslinker also affects the reaction particularly in the case of a hydrogel prepared in water. As a result, the influence of the crosslinking agent on the gel has been difficult to be investigated so far in spite of the importance in gel properties [21].We are focusing on a gel synthesis by post-polymerization crosslinking (PPC) system in which prepolymers having activated ester moieties are reacted with a diamine compound as a crosslinker (Scheme 1a) [22][23][24][25][26]. This method is performed by simply mixing a prepolymer with a crosslinker, and it is possible to diversely change the gel structure by an appropriate design of the prepolymer.…”

“…We are focusing on a gel synthesis by post-polymerization crosslinking (PPC) system in which prepolymers having activated ester moieties are reacted with a diamine compound as a crosslinker (Scheme 1a) [22][23][24][25][26]. This method is performed by simply mixing a prepolymer with a crosslinker, and it is possible to diversely change the gel structure by an appropriate design of the prepolymer.…”