Lower critical solution temperature Methacrylate

Lower critical solution temperature Methacrylic acid Methyl methacrylate... 

Maderek, E. Schulz, V. Wolf, B. A., "Lower Critical Solution Temperatures of Poly(decyl methacrylate) in Hydrocarbons," Eur. Polym. J., 19, 963 (1983). 

These polymers were selected owing to their ability to promptly transit from hydrated coil to dehydrated globule conformation when temperature increases above their lower critical solution temperature (LCST). Homopolymers of NIPAM have a LCST in aqueous media around 32°C, which is not compatible with physiological conditions. Thus, to be exploitable for in vivo drug delivery, this temperature must be increased by copolymerization with other hydrophilic monomers. When these monomers have ioniz-able moieties such as methacrylic acid (MAA, pKa=5.4), the increase in LCST is dependent on ionization, and therefore the polymers acquire pH-dependent physiological solubility (2). 

The PPE blends with polyphenyl methacrylate, poly(p-methoxy phenyl methacrylate), poly(benzyl methacrylate), or poly(3-phenyl propyl methacrylate) were reported to have the lower critical solution temperature, LOST = 105-150°C [Eischer and Siol, 1993, 1995],... 

WEB Weber,C., Becer, C.R., Hoogenboom, R., and Schubert, U.S., Lower critical solution temperature behavior of comb and graft shaped poly[ohgo(2-ethyl-2-oxazoline) methacrylate]s,M7crorwo/ecM/e5, 42, 2965, 2009. 

Thermoresponsive Polymers. Poly[(ethylene glycol) methacrylate] (PEGMA) and poly(iV-isopropylacrylamide) (PNIPAam) are well-studied polymers for imparting thermoresponsive properties to cationic vectors. These polymers undergo a phase transition (from random coil to globular form) at a lower critical solution temperature (LCST) near the... 

By radical copolymerization of poly(A/-isopropylacrylamide-co-N,iV-dime-thylaminoethyl methacrylate) [poly(NIPAM-co-DMAEMA)] macromonomer with the monomers NIPAM and DMAEMA, comb-type cationic hydrogels with poly(NIPAM-co-DMAEMA) backbone networks and grafted poly(NIPAM-co-DMAEMA) side chains can be successfully prepared. Within the comb-type hydrogels the grafted chains have freely mobile ends, which are distinct from typical network structures of normal-type crosslinked hydrogels, as shown in Figure 5.7. The obtained hydrogels show both temperature and pH sensitivity. They all deswell with an increase of temperature and/or pH, and exhibit a lower critical solution temperature (LCST) at about 34 °C and a p a value at about pH 7.3. 

Miscibility of PPE with PS has been known since 1960. Later, two other PPE blends were announced miscible. PPE blends with polytransoctanylene (PTO) can be processed at 260 °C and have HDT > 194 °C. The patents suggested that PTO is miscible with PPE (Jadamus et al. 1986, 1987). The PPE blends with polyphenyl methacrylate, poly(p-methoxy phenyl methacrylate), poly(benzyl methacrylate), or poly(3-phenyl propyl methacrylate) were reported to have the lower critical solution temperature, LCST = 105-150 °C (Fischer and Siol 1993, 1995). 

Goh, Paul, and Barlow [10] found that an alpha-methylstyrene-acrylonitrile (AMS-AN) copolymer at 50 mole fraction AN formed miscible polymer blends with poly(methyl methacrylate) (PMMA) and with poly(ethyl methacrylate) (PEMA). AMS-AN copolymer did not form miscible blends with polyacrylates or polyvinyl acetate. The miscible blends were found to exhibit lower critical solution temperature (LCST) behavior. 

Works on the co-micellization of PEO-( -poly(methacrylate) (PEO- -PMA) with charged surfactants were also published [110]. The PEO-fe-PMA copolymers belong to the group of so-called double hydrophilic BCPs. A special case in this group are double hydrophilic BCPs, which have one block that can become hydrophobic upon heating or due to changes in other external parameters. An example of this kind of systems is PEO-fc-poly(lV-isopropylacrylamide) (PEO- -PNIPAM), which was studied recently [111]. PNIPAM has a 6 temperature of ca. 33°C in water and wants to phase-separate beyond this so-called lower critical solution temperature (LCST). In the following subsections all the mentioned works will be summarized. 

---