Tailoring of Stimuli-Responsive Water Soluble Acrylamide and Methacrylamide Polymers

Water‐soluble polymers with tunable temperature sensitivity: Solution behavior

“…1(b)]. This suggests that the collapsed coils do not form micelles, as is the case with branched or random/block copolymers, 6 and in contrast to the poly(dimethylsiloxy-co-ethyleneoxide) behavior they are less susceptible to hydrolysis. 12 The overall solubility phase diagram is similar to the calculated neat PEO phase diagram but at considerably lower temperatures, as expected by the addition of the hydrophobic ethylene part in the monomer.…”

“…6 -8 These branched polymers exhibit cloud points (CPs) that do not correlate with the hydrophobic/hydrophilic balance of the polymer. 6 This behavior originates from the branched molecular architecture of these materials that results in a coil to micelle "phase transition" rather than a polymer solution (LCST) phase transition. Bokias et al 7 showed that increasing the length of the hydrophobic side chains can shift the LCST of PNI-PAM, but now the phase transition broadens and occurs over a wide temperature range.…”

“…Virtanen et al, 8 who investigated PNIPAM modified with poly(ethylene oxide) (PEO) grafts, also found the same broadening of phase transition that they attributed to the collapsed aggregate formation-a micelle that consists of a PNI-PAM/PEO core with a PEO shell. Such coil-to-micelle transitions make it difficult to predict the behavior of branched-modified thermosensitive polymers on the basis of the balance of hydrophilic and hydrophobic molecular segments, 6 thus limiting dramatically the ability to design polymers with tailored temperature response in aqueous solutions.…”

Temperature-Responsive Polymers for Biological Applications

“…Taylor and Cerankowski [14] predicted that LCST of a water soluble polymer can be varied by controlling balance of hydrophilic and hydrophobic segments in the polymer chain. However, to date most polymers studied are based on a single homopolymer (PNIPAM), that exhibits LCST at 32 0 C [15], and efforts to change its LCST mostly involved modifications through addition of hydrophobic branches [15,16,17]. These branched polymers exhibit cloud points (CP) that do not correlate with the hydrophobic/hydrophilic balance of the polymer [15].…”

“…However, to date most polymers studied are based on a single homopolymer (PNIPAM), that exhibits LCST at 32 0 C [15], and efforts to change its LCST mostly involved modifications through addition of hydrophobic branches [15,16,17]. These branched polymers exhibit cloud points (CP) that do not correlate with the hydrophobic/hydrophilic balance of the polymer [15]. This behavior originates from the branched molecular architecture of these materials, which results in a coil to micelle "phase transition", rather than a polymer solution (LCST) phase transition.…”