I just want to use a temperature sensitive polymer or hydroge with a LCST about 55 degree for encapsulating some nanomatetials.Please give me some professional advices and references.Thank you very munch!
I've read that co-polymerization of OEGMA and DEGMA can be used as a way to create polymers with different LCST. Here is a paper with some more information:
http://pubs.rsc.org/en/Content/ArticleLanding/2011/PY/c0py00417k#!divAbstract
1) Some cellulose derivatives (methyl and hydroxypropyl methylcellulose) at low concentrations (1–10 wt%) are liquid at low temperature, but jellify upon heating, however their gelation temperature is far above body temperature.
2) The incorporation of hydrophilic monomers in pNIPAM increases the LCST, whereas more hydrophobic units decreases it.
3) The gelation behavior of poly(d,l-lactide-co-glycolide)–poly(ethylenglycol)–
poly(d,l-lactide-co-glycolide) (PLGA-PEG-PLGA) is influenced by the hydrophobicity
of end caps (hydroxy, acetyl, propionyl, and butanoyl groups); decrease in the
hydrophobicity of the copolymer increase in the transition temperature.
4) Pluronics
5) poly(hydroxylpropyl methacrylamide lactate)
6) Multiblock poly(ester amino urethane)s that are pH and temperature sensitive is synthesized by coupling poly(amino urethane) (PAU) through a condensation reaction to PCL-PEG-PCL triblock copolymers to yield multiblock copolymers (PCL-PEG-PCL-PAU)n. The incorporation of the ionizable PAU segments in the macromolecule induces pH sensitivity due to the tertiary amine moieties. Thus, below pH 6.9 the polymer is in a sol state in aqueous solution up to 60 °C due to the electrostatic repulsion of the piperazine groups. At physiological pH (pH 7.4) the solution displays a sol–gel transition upon increasing temperature to 37 °C. The formation of the free-standing gel depends on the formation of interconnected micelles. The formation of a gel is assessed in vivo and injectable poly(amidoamine)-poly(ethylene glycol)-poly(amidoamine) triblock copolymer hydrogels exhibiting pH and temperature sensitivity is designed for bioadhesive applications. The dual responsiveness depends upon the poly(amidoamine) outer blocks which turns from a hydrophilic into hydrophobic state upon increasing pH and/or temperature. At low pH a sol is observed up to 60 °C, while above pH 7.0 the micelles bridged, leading to the formation of a gel.
7) The block copolymers OSM (sulfamethazine oligomers)−PCLA−PEG−PCLA does not form a gel at pH 8.0 in the tested temperature range (from 4 to 60 °C) because the hydrophobic interaction between PCLA−OSM blocks is perturbed by the ionized sulfonamide group of the OSM block.
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