Synthesis and characterization of organosiloxane modified segmented polyether polyurethanes

Wang, L.F.; Ji, Qing; Glass, T. E.; Ward, T. C.; McGrath, James E.; Muggli, Mark; Burns, Gary T.; Sorathia, Usman

doi:10.1016/s0032-3861(99)00570-4

Cited by 155 publications

(121 citation statements)

References 10 publications

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“…Those findings seem to make the evidence for the formation of complex silicon-based structures in the pyrolysis process. The structures are formed on the surface and probably create the insulating layer which slows down further decomposition of the polymer, as it was observed for polyurethane-siloxane copolymers [30].…”

Section: Thermal Decomposition In Airmentioning

confidence: 81%

Effect of different polyethers on surface and thermal properties of poly(urethane-siloxane) copolymers modified with side-chain siloxane

Byczyński

2013

J Therm Anal Calorim

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Poly(urethane-dimethylsiloxane) (PU-PDMS) copolymers with 4,4 0 -methylenebis(cyclohexyl isocyanate), different polyethers i.e., poly(oxytetramethylene)diol, poly (ethylene glycol), poly(propylene glycol), and a,x-dihydroxy terminated polydimethylsiloxane extended with 1,4-butanediol in two-step solution polymerization were obtained. The PU-PDMS were modified using 1.25 mol% of polydimethylsiloxane which was incorporated into main polyurethane backbone as a side chain. The structure of the synthesized PU-PDMS was confirmed by FTIR as well as 1 H and 13 C-NMR spectroscopy. The effect of different soft segments on free surface energy (FSE) components and thermal stability of poly(urethane-siloxane) copolymers was investigated. The activation energy of the thermal degradation of PU-PDMS using isoconversional methods (OzawaFlynn-Wall and Friedman) was calculated. It was concluded that molecular mass, thermal stability, and FSE of PU-PDMS copolymers depend on polyol used. The apparent activation energy at first step of degradation in nitrogen generally increases with the extent of conversion which may result from complex mechanism related to formation of decomposition products. Hydrophobic character of side-chain siloxane on surface properties of the PU-PDMS coatings was confirmed. The obtained coatings are generally soft with the relative hardness in the range of 0.120-0.027.

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Section: Thermal Decomposition In Airmentioning

confidence: 81%

Effect of different polyethers on surface and thermal properties of poly(urethane-siloxane) copolymers modified with side-chain siloxane

Byczyński

2013

J Therm Anal Calorim

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“…PSiU and silicone-urea segmented copolymers were investigated by numerous research groups to understand the relationship between their structure and thermal or mechanical behaviour [5][6][7][8][9][10]. It was found that the polysiloxane chains are phase separated from the hard segments (HS), consisting of mostly 4,4!-methylene diphenylene diisocyanate (MDI) and 1,4-butanediol (BDO), and also from the polyether soft segments (SS).…”

Section: Introductionmentioning

confidence: 99%

The effect of some disiloxane chain extenders on the thermal and mechanical properties of cross-linked poly(siloxane-urethane)s

Pusztai¹,

Kenyo²,

Nagy³

et al. 2013

Express Polym. Lett.

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Abstract. Poly(siloxane-urethane) (PSiU) networks based on a bis(hydroxyorgano) disiloxane chain extender, a trifunctional polyether polyol as a cross-linker, methylene-diphenyl diisocyanate and #,$-hydroxyethoxyethyl polydimethylsiloxane were synthesized in butyl acetate solution. The effect of the chain extenders and the cross-link density was investigated by using thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMTA), swelling, hardness and tensile strength measurements. Isotherm thermogravimetric analyses were carried out for selected polymer compositions at 120 and 170°C and also the changes in tensile strength were followed. The different chain extenders have a strong effect on the hard segment structure, thus on the thermal and mechanical behaviour. The phase separation of the soft and hard segments was indicated by the two or three well distinguished tan% peaks, the maxima of which range within wide intervals depending on the polymer composition. The polymers of high cross-link density showed a very good thermal stability, high tensile strength (up to 68.7 MPa) and hardness (80-95 Shore A) even of high 13-36% dimethyl siloxane content. Changing the siloxane soft segment ratio and the cross-link density the physical properties can be adjusted.

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“…The band at 2935 cm −1 is assigned to the C-H stretching [27]. The peaks at 1605, 1416, 1250, and 1022 cm −1 represent COOasymmetric stretching [28], COO-symmetric stretching [29,30], CH3 symmetric bending [31], and C-O-C anti-symmetric stretching [32,33], respectively. For C. crispus biomass, the main bands relate to -OH overlapping (3283 cm −1 ) [26], C-H stretching (2924 cm −1 ) [27], C=C stretching (1644 cm −1 ) [34], N-H bending and C-N stretching (1531 cm −1 ) [35], COO− symmetric stretching (1416 cm −1 ) [29,30], S-O stretching (1152 and 1221 cm −1 ) [36,37], C−O−C antisym.…”

Section: Characterizationmentioning

confidence: 99%

A Comparison of Palladium Sorption Using Polyethylenimine Impregnated Alginate-Based and Carrageenan-Based Algal Beads

2018

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Two kinds of algal beads were prepared using a carrageenan-based alga (Chrondrus crispus) and an alginate-based alga (Laminara digitata) ionotropically gelled with K(I) and Ca(II), respectively: the process consists of biopolymer partial extraction followed by hydrogel formation. The beads were modified with branched polyethylenimine (bPEI) and glutaraldehyde (GA) using the impregnation method to improve their sorption capacity for Pd(II) in acid solution. SEM-EDX and FTIR techniques were used for characterizing the beads. The impacts of pH and presence of anions, cations, and Pt(IV) were studied in batch experiments. The beads were also applied for Pd(II) recovery from synthesized leaching liquors of a spent catalyst and a car catalytic converter via the sorption-desorption process. Results show that Pd is concentrated in the outer layer of L. digitata-bPEI-GA composite (LD/PEI) beads, while in the case of the C. crispus-bPEI-GA composite (CC/PEI), it is homogenously distributed in the whole mass of the sorbents. The difference is attributed to the repulsive force of the outer Ca(II)-alginate barrier of LD/PEI beads that makes it difficult for the branched polymer PEI to penetrate through the layer and be immobilized in the inner compartment. As a result, LD/PEI beads possess a lower maximum sorption capacity, but a slightly faster uptake at pH 1 than CC/PEI beads. In addition, CC/PEI beads present a better recovery performance compared to LD/PEI beads when applied for the treatment of synthesized leaching liquors.

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Synthesis and characterization of organosiloxane modified segmented polyether polyurethanes

Cited by 155 publications

References 10 publications

Effect of different polyethers on surface and thermal properties of poly(urethane-siloxane) copolymers modified with side-chain siloxane

Effect of different polyethers on surface and thermal properties of poly(urethane-siloxane) copolymers modified with side-chain siloxane

The effect of some disiloxane chain extenders on the thermal and mechanical properties of cross-linked poly(siloxane-urethane)s

A Comparison of Palladium Sorption Using Polyethylenimine Impregnated Alginate-Based and Carrageenan-Based Algal Beads

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