Synthesis of functional telechelic polydimethylsiloxanes by ion-exchangers catalysis

Summary: Monosaccharide functionalized polysiloxanes bearing either terminal or pendant mannose moieties have been obtained starting from the allyloxyethyl glycoside and appropriate H‐containing siloxane compounds, via hydrosilylation reactions. The starting modified monosaccharide was reacted as trimethylsilyl protected derivative and a convenient method for deprotection of the hydroxyl groups was found in order to avoid the degradation of the polysiloxane chains. The reaction products were characterized by IR and NMR spectroscopy. The water solubility of these functionalized polysiloxanes was investigated and critical micelle concentration values were found to be in the range 10−4–10−5 M. Some of the water soluble compounds were used as non ionic surfactants for the elaboration of poly(ε‐caprolactone) nanoparticles by nanoprecipitation, and particle sizes of less than 200 nm were observed.

Section: Syntheses Of Precursorsmentioning

confidence: 99%

Synthesis and Characterization of Water Soluble Saccharide Functionalized Polysiloxanes and Their Use as Polymer Surfactants for the Stabilization of Polycaprolactone Nanoparticles

Racleş¹,

Hamaide

2005

“…[20] The general procedure for obtaining carboxypropyl terminated siloxane oligomers of different molecular weights has been reported previously by our group. [21] The polydispersity of the obtained oligomers was about 1.5. 1,3-Bis(sebacomethyl)tetramethyldisiloxane was synthesized from 1,3-bis-(chloromethyl)tetramethyldisiloxane, according to a previously known method.…”

Section: Experimental Partmentioning

confidence: 93%

New Siloxane‐Organic Polyesters with Azobenzene Side Chains. Synthesis, Thermotropic Behavior and Surface Properties

Racleş¹,

Filip²,

Cazacu³

et al. 2006

Summary: New siloxane‐organic polyesters, bearing azo‐type units in the side chain, were synthesized by direct solution polycondensation at room temperature, starting from 2,2′‐[4‐[(4‐nitrophenyl)azo]phenyl]iminobisethanol (Disperse Red 19) and different siloxane diacids, using dicyclohexylcarbodiimide as an activator and 4‐(N,N‐dimethylamino)pyridinium‐p‐toluenesulfonate as the catalyst. The structure of the obtained polyesters was confirmed by 1H and 13C NMR as well as IR spectroscopy. The molecular weight and polydispersity were estimated by GPC. The thermotropic behavior was investigated by POM, DSC and TOA. The surface composition was determined by ESCA (XPS) analysis and proved enrichment in silicon for all samples. All compounds show good solubility in common organic solvents.An example of a nitroazobenzene‐containing side‐chain polyester with various siloxane‐organic backbones.imageAn example of a nitroazobenzene‐containing side‐chain polyester with various siloxane‐organic backbones.

“…The hydrosilation reaction has been used in industry [18,19] to synthesize functionally terminated siloxane oligomers and various linear segmented copolymers. [20] Silicones can be end-capped with various reactive groups such as epoxides, [21,22] amines, [23,24] vinyl, [25] and sulfides. [26,27] To expand and improve properties of silicones, it has been proposed to replace the phenyl or methyl substituent with cycloaliphatic group.…”

Section: Full Papermentioning

confidence: 99%

Synthesis of Amine and Epoxide Telechelic Siloxanes

Chakraborty

Soucek

2008

A synthetic route was developed to prepare thermosetting methyl, cyclopentyl, and cyclohexyl substituted polysiloxanes with epoxide or amino end groups. Cycloalkene (cyclopentene or cyclohexene) and dichlorosilane gas were reacted at 180 °C, and at high pressure (2 MPa) to produce dicycloaliphatic dichlorosilane. Hydrolytic condensations of the dichlorosilanes were performed affording low molecular weight cyclic siloxane oligomers. Base catalyzed ring opening polymerization of the cyclic oligomers afforded the hydride‐terminated polysiloxanes. The hydride‐terminated polysiloxanes were then functionalized with glycidyl epoxide or aliphatic amine groups via hydrosilation reactions. The oligomers and polymers were characterized by 1H NMR, 13C NMR, 29Si NMR, FTIR, and GPC. The molecular weight of polydimethylsiloxane, polydicyclopentylsiloxane, and polydicyclohexylsiloxane oligomers were $\overline M _{\rm n}$ = 1 000, 1 200, and 1 500, respectively. The polydispersity index of all the cyclic oligomers was ≈1.15. Differential scanning calorimetry (DSC) was used to evaluate the crosslinking reaction and the glass transition temperature of the thermally cured systems. Crosslinking occurred at 120 °C and the Tg of the methyl, cyclopentyl, and cyclohexyl functionalized siloxanes were found to be at −104, −93, and −82 °C, respectively.magnified image