Synthesis, characterization and properties of chitosan modified with poly(ethylene glycol)–polydimethylsiloxane amphiphilic block copolymers

Rutnakornpituk, Metha; Ngamdee, Paradorn; Phinyocheep, Pranee

doi:10.1016/j.polymer.2005.08.051

Cited by 58 publications

(30 citation statements)

References 29 publications

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“…The signal at δ =0.1 (a) and δ =3.6 (b) ppm is attributed to the protons of Si-CH 3 bond and O-CH 2 -CH 2 bond, respectively. The signals at δ =3.3 (c), δ =1.1 (d) and δ =3.5 (e) ppm are ascribed to the protons of O-CH(CH 3 )-CH 2 bond orderly [32][33][34]. The silicone/polyether ratio of each silicone surfactant can be obtained by estimating area of each signal which indicates the number of protons exists.…”

mentioning

confidence: 99%

Effects of silicone surfactant on the cell size and thermal conductivity of rigid polyurethane foams by environmentally friendly blowing agents

Han¹,

Choi²,

Kim³

et al. 2009

Macromol. Res.

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Rigid polyurethane foams (PUF)s were synthesized with environmentally friendly blowing agents such as a cyclopentane/distilled water (10.0/1.0, pphp) mixture and distilled water only for four different silicone surfactants having different silicone/polyether ratios. An attempt was made to reduce the thermal conductivities of the PUF samples by varying the concentration and the silicone/polyether ratio of the various silicone surfactants. The scanning electron microscopy (SEM) results indicated an optimum concentration of the silicone surfactant of about 1.5 to 2.5 phpp for various surfactants to reduce the cell size and lower the thermal conductivity. The silicone surfactant having a higher silicone/polymer ratio showed a smaller cell size and, therefore, demonstrated the lower thermal conductivity of the PUF samples. From the relation between the thermal conductivity and the cell size of the PUF samples, the smaller cell size improved the thermal insulation property of the rigid PUF for both the PUF samples blown by the cyclopentane/distilled water (10.0/1.0, pphp) mixture and distilled water only. If the blowing agent is fixed, then the cell size is an important factor to decrease the thermal conductivity of the PUF samples. These results indicated that rigid PUF samples having lower thermal conductivity can be obtained by choosing a silicone surfactant containing a higher silicone/polyether ratio, as well as an optimum content of the surfactant.

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mentioning

confidence: 99%

Effects of silicone surfactant on the cell size and thermal conductivity of rigid polyurethane foams by environmentally friendly blowing agents

Han¹,

Choi²,

Kim³

et al. 2009

Macromol. Res.

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“…During the reaction, samples were withdrawn at various times for kinetics study by GPC. When the molecular weight values remained constant, the reaction mixture was filtered in order to remove the catalyst and distilled at 160 The reaction between PDMSgPEO-OH and succinic anhydride (OH/succinic anhydride=1/1.1 molar ratio) was performed by bulk condensation in the presence of dibutyltin oxide [16,17]. The reaction mixture was maintained at 180 o C under nitrogen, for 24 h when the unreacted succinic anhydride sublimed on the wall of the flask.…”

Section: Synthesis -Synthesis Of Polydimethylsiloxane With Hydride (Hmentioning

confidence: 99%

Synthesis and micellization of polydimethylsiloxane– carboxy-terminated poly(ethylene oxide) graft copolymer in aqueous and organic media and its application for the synthesis of core-shell magnetite particles

Pricop¹,

Durdureanu-Angheluta

Spulber³

et al. 2010

E-Polymers

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An amphiphilic graft copolymer having an average of 7-8 carboxyesterterminated poly(ethylene oxide) grafted sequences on each polydimethylsiloxane main chain was obtained by a multistep procedure. Through fluorescence, surface tension and laser diffractometry methods the graft copolymer was proved to undergo micellization in aqueous media. In water, the critical micellization concentrations (CMC) are dependent on pH. Two CMC values were established for pH = 4, i.e. CMC 1 = 1.01 g/L and CMC 2 = 1.73 g/L corresponding to the transition from single chain to multiple chain micelles and to intermicellar aggregation, respectively. Between CMC 1 and CMC 2 , the dimensions of micelles increased from 18 nm to 46 nm. The graft copolymer was proved to efficiently act as surfactant in the preparation of magnetite particles with a hydrophobic siloxane shell.

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“…18,19 Several approaches have been reported to combine PEG and PDMS; mainly through covalently linking linear PEG with linear PDMS to form a diblock copolymer, [20][21][22] end-capping linear PEG with linear PDMS to form a triblock copolymer, 23,24 and end-capping linear PDMS with linear PEG to form a triblock copolymer. 10,25,26 Other examples include a random-grafted PEG/PDMS copolymer 27 and a commercially available grafted PEG along a PDMS backbone. To the best of the authors' knowledge, no studies have reported the synthesis of a welldefined PEG/PDMS-grafted BCPs.…”

Section: Introductionmentioning

confidence: 99%

Soft nanoparticles assembled from linear poly(ethylene glycol) and linear brush polydimethylsiloxane diblock copolymers

Halim

Reid

Ren

et al. 2014

J. Polym. Sci. Part A: Polym. Chem.

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A series of novel amphiphilic diblock copolymers composed of hydrophilic linear poly(ethylene glycol) (PEG) and linear brush hydrophobic polydimethylsiloxane (PDMS) were synthesized. Three different molecular weights of monomethyl ether PEG were initially functionalized with 2-bromoisobutyryl bromide to afford macroinitiators suitable for atom-transfer radical polymerization. The macroinitiators were characterized by gel permeation chromatography, 1 H and 13 C nuclear magnetic resonance spectroscopic analysis and matrix-assisted laser desorption ionization time-of-flight mass spectroscopy. The three different molecular weight macroinitiators were then chain extended with monomethacryloxypropyl-terminated PDMS and photoactive 2-(methylacyloyloxy)ethyl anthracene-9-carboxylate in different molar ratios to afford a series of photoresponsive amphiphilic diblock copolymers with high conversions. Self-assembly of these linear-linear brush diblock copolymers in N,N-dimethylformamide afforded nanoparticles with hydrodynamic diameters (d H ) ranging from 41 to 268 nm, as determined by dynamic light scattering analysis. Crosslinking and stabilization of the nanoparticles was achieved via [414] photodimerization of the anthracene moieties upon exposure to UV radiation at 365 nm with the reverse reaction studied at a wavelength of 254 nm. Transmission electron microscopy revealed that the self-assembled nanoparticles and their crosslinked derivatives had spherical morphologies.

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Synthesis, characterization and properties of chitosan modified with poly(ethylene glycol)–polydimethylsiloxane amphiphilic block copolymers

Cited by 58 publications

References 29 publications

Effects of silicone surfactant on the cell size and thermal conductivity of rigid polyurethane foams by environmentally friendly blowing agents

Effects of silicone surfactant on the cell size and thermal conductivity of rigid polyurethane foams by environmentally friendly blowing agents

Synthesis and micellization of polydimethylsiloxane– carboxy-terminated poly(ethylene oxide) graft copolymer in aqueous and organic media and its application for the synthesis of core-shell magnetite particles

Soft nanoparticles assembled from linear poly(ethylene glycol) and linear brush polydimethylsiloxane diblock copolymers

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