Structural effect of a series of block copolymers consisting of poly(N-isopropylacrylamide) and poly(N-hydroxyethylacrylamide) on thermoresponsive behavior

Thermo-responsive block copolymers with multiple phase transition temperatures in aqueous solutions

“…For example, the cloud point-increasing effect of the more hydrophilic PEG on the block and graft copolymers of PiPA has been well demonstrated[114][115][116][117][118][119], although the demixing temperature and kinetics have been reported to strongly depend on the polymer architecture and concentration, as T dem decreases significantly at high concentrations[120]. The effect of the relative block lengths on the LCSTs has also been demonstrated for other thermo-responsive block copolymers with a single LCST[121][122][123].Laschewsky and coworkers showed a shift in the CPs of dually thermo-responsive PnPA-b-PEA diblock copolymers according to the relative block lengths[124].When the relative length of the more hydrophilic PEA block increased upon changing the nPA:EA ratio from 2:1 to 1:1 and further to 1:3, the CP of the more hydrophobic PnPA block increased from 17 to 23 and then to 27 °C, respectively.The less pronounced CPs of the PEA block were in the range of 60−70 °C. The hydrophobic end group from CTA participated the aggregation process and its immobilization upon aggregation depended on whether it was attached to PnPA or PEA block.…”

Thermosensitive copolymer with cobalt phthalocyanine and catalytic behavior based on adjustable LCST

“…Poly(N-isopropylacrylamide) (PNIPA) is one of the most popular thermosensitive polymers, and undergoes a sharp conformational transition from a water-soluble random coil into water-insoluble globule forms at 32-34°C in aqueous solution [19][20][21][22]. To obtain MtPc catalysts that have a low aggregation tendency and can be recycled, our group has explored a general approach to the synthesis of polymeric MtPc catalysts by introducing a polymerizable N-acrylic carbonyl group into the side chains of cobalt tetraaminophthalocyanine (Co-APc) and then copolymerizing with N-isopropylacrylamide (NIPA) [23].…”

NMR of liquid crystals and micellar solutions

“…123 The structural basis of the thermoresponsive property of a series of block copolymers consisting of PNIPAM and poly(N-hydroxyethylacrylamide) (PHEAA) was elucidated by 1 H NMR measurements. 124 Thermosensitive and pegylated polyion complex micelles were formed by co-assembly of the oppositely and permanently charged block copolymers poly(sodium 2-acrylamido-2-methylpropanesulfonate)-bpoly(N-isopropylacrylamide), PAMPS-b-PNIPAM, and poly((3-acrylamidopropyl)-trimethylammonium chloride) (PAMPTMA)-b-PEO. These micelles were characterized by 1 H NMR, SLS, DLS, and TEM.…”