813460-60-5Relevant articles and documents
Synthesis and characterization of environmentally benign, semifluorinated polymers and their applications in drug delivery
Fleetwood, Michelle C.,McCoy, Aaron M.,Mecozzi, Sandro
, p. 75 - 80 (2016/09/16)
We describe the synthesis, physicochemical studies and pharmaceutical assessment of a class of pegylated semifluorinated amphiphilic block-copolymers based on short pendant fluorinated side chains attached to moderately hydrophobic units. These polymers allowed us to investigate how the balance between hydrophobicity and fluorophilicity in the polymer can be tuned to match that of small molecules to be used in drug delivery. Remarkably, we found that using short perfluoroethyl groups in the polymer allows the preferential stabilization of nanoemulsions based on isoflurane, a fluorinated anesthetic made partly hydrophobic by the presence of a chlorine atom. In comparison, nanoemulsions of sevoflurane, a purely fluorophilic anesthetic, were not as stable. The lipophilicity of the polymers was also investigated in regards to solvation of hydrophobic molecules. Surface properties such as critical micelle concentration (CMC) and surface tension demonstrated the uniqueness of these fluorinated amphiphiles. Finally, the use of short perfluoroethyl chains makes these polymers environmentally benign in terms of bioaccumulation and toxicity.
A ruthenium-catalyzed hydrosilane-induced polymerization of 3-alkyl-3-hydroxymethyloxetane derivatives: Facile access to functionalized polyoxetanes by virtue of organosilyl groups
Harada, Nari-Aki,Yasuhara, Jushiro,Motoyama, Yukihiro,Fujimura, Osamu,Tsuji, Tetsuro,Takahashi, Takeshi,Takahashi, Yoshiaki,Nagashima, Hideo
supporting information; experimental part, p. 26 - 39 (2011/03/22)
Ring-opening polymerization of 3-alkyl-3-alkoxymethyl- or 3-alkyl-3-siloxymethyloxetanes is catalyzed by a triruthenium cluster, [Ru 3{μ3-(η2,η3, η5-C12H8)}(CO)7], in the presence of trialkylsilanes, providing a novel accessible method for functionalized polyoxetanes of Mn = 103-105. Oxetanes having alkoxy-, fluoroalkoxy-, triethyleneglycoloxy-, and trialkylsiloxy functions undergo polymerization and copolymerization. Consumption rates of two monomers in the copolymerization of 3-benzyloxymethyl- and 3-trimethylsiloxymethyl-3-alkyloxetanes are almost the same, indicating formation of random copolymers. The organosilyl group in the polymer and copolymers with siloxymethyl side chains is converted to CH3OH or CH2OCOR groups by hydrolysis or silyl/acyl exchange. These protocols give the way to access polymers or copolymers bearing OH and OCOR side chains. A ruthenium-catalyzed reaction of 3-ethyl-3- hydroxymethyloxetane with trialkylsilanes results in dehydrogenative silylation to give 3-ethyl-3-siloxymethyloxetane, which is followed by ring-opening polymerization. Combination of tandem dehydrogenative silylation/ring-opening polymerization/the silyl/acyl exchange realizes one-pot synthesis of polymers with CH2OCOR side chains from 3-ethyl- 3-hydroxymethyloxetane. DSC analyses of the formed polymers provided Tg and Tm data, which are a good example showing that the polymer properties are controlled by appropriate selection of functional groups at the side chain.
