Tetramethylammonium 3‐aminopropyl dimethylsilanolate—aminopropyl dimethylsilanolate—a new catalyst for the synthesis of high purity, high molecular weight α,ω‐bis(aminopropyl) polydimethylsiloxanes

Hoffman, Jerome J.; Leir, Charles M.

doi:10.1002/pi.4990240302

Cited by 22 publications

(16 citation statements)

References 8 publications

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“…Bis(3-aminopropyldimethyl) polydimethylsiloxanes (silicone diamines) were synthesized according to the procedure described by Leir et al, 1 which provides highly difunctional silicone diamines. Number-average molecular weights of the silicone diamines were determined by acid titration with 0.1 N HCl, using bromophenol blue as an indicator.…”

Section: Amine-functional Siloxane Iintermediatesmentioning

confidence: 99%

Novel materials based on silicone-acrylate copolymer networks

Mazurek¹,

Kinning²,

Kinoshita³

2001

J. Appl. Polym. Sci.

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This article presents a broad class of materials made by copolymerization of a family of telechelic free radically polymerizable siloxanes with various acrylate monomers that polymerize to form high Tg polymers. Films with properties ranging from strong elastomers to plastics have been obtained by UV‐initiated bulk copolymerization of functional siloxanes dissolved in acrylate monomers (in the presence of a photoinitiator). The molecular weight of the functional siloxanes, the nature of functional endgroups, the choice of (meth)acrylate comonomer, and the siloxane/acrylate ratio all have a rather dramatic effect on the morphology, and thus, on the properties of the copolymeric networks. Physical properties of the materials, such as optical appearance and mechanical and transport properties are correlated with the unique morphologies observed by TEM studies. Unusual properties such as reversible whitening of some of the materials and low Poisson ratios have been attributed to the microcavitation observed when high Tg acrylate domains interfere with the network deformation. Networks composed of high Tg acrylates (major fraction) coreacted with elastomeric siloxanes can provide heat‐shrinkable materials when they are elongated at temperatures higher than the Tg of the corresponding polyacrylates and quenched. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 159–180, 2001

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Section: Amine-functional Siloxane Iintermediatesmentioning

confidence: 99%

Novel materials based on silicone-acrylate copolymer networks

Mazurek¹,

Kinning²,

Kinoshita³

2001

J. Appl. Polym. Sci.

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“…These polymeric precursors with molecular weights in the range 5,000-55,000 g/mole, having good functionality (high degree of end-labeling), were prepared by the modified method of the base-catalyzed equilibration of D 4 with 3,3 0 -bis-aminopropyl tetramethyldisiloxane, as described by Hoffman and Leir. 13 The number average molecular weights of polymers having normal distribution were determined by an acid titration of the amine end groups. In some experiments, different lots of materials with somewhat different molecular weights were used.…”

Section: Difunctional Siloxanesmentioning

confidence: 99%

“…[8][9][10][11][12] Telechelic siloxanes based on high purity silicone diamines have been extensively studied in this laboratory as new methods of synthesis of silicone precursors were developed. 13 Some very early results of studies of free-radically polymerizable telechelic siloxanes have been presented. 14 These initial results revealed the applicability of those materials in the study of fundamental issues of network theory and rubber elasticity, and selected materials from this group have been used in model studies elsewhere.…”

Section: Introductionmentioning

confidence: 99%

Telechelic siloxanes with hydrogen‐bonded polymerizable end groups. I. Liquid rubbers and elastomers

Leir

Galkiewicz

Kantner

et al. 2010

J of Applied Polymer Sci

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Functional siloxanes are widely used in the synthesis of model networks used in rubber elasticity studies, and various functional siloxanes are also used in the synthesis of silicone rubbers. We present here the results of studies of two classes of telechelic, free-radically polymerizable siloxanes carrying either amide or urea groups attached at both ends of siloxane chain. The presence of polar, hydrogen-bonding end-groups favors the formation of aggregates which is reflected in the drastically increased viscosity of the resulting ''liquid rubbers.'' In addition, such aggregation accounts for high local concentrations of reactive groups thus making it possible to have high molecular weight precursors undergo facile room temperature polymerization. In this article, we study the effect of the nature of these functional groups on the viscosity of polymerizable ''liquid rubbers,'' finding that the different endgroups lead to dramatically different viscosities. We also study the silicone rubber films obtained by a UV-initiated free-radical polymerization of the liquid rubbers, using dynamic mechanical analysis and large-strain uniaxial deformation. We find here that important properties such as plateau modulus and Young's modulus are highly dependent on both endgroup type and precursor molecular weight. The crosslinking of telechelic siloxanes in dilution was also studied to further explore the effect of crosslink density of the mechanical properties of the model networks. Finally, we evaluated the role of dangling ends within the networks through the incorporation of monofunctional macromers.

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“…[32] Amino functionalized siloxanes have been extensively studied as a component of a large number of segmented materials. [33][34][35][36][37] Amine-terminated siloxanes are used to synthesis polyureas with superior mechanical strength properties due to segregated morphologies. [38] A typical synthetic approach which has been reported recently by Dworak and Soucek involves the reaction of cyclic polysiloxane oligomers with 1,3-bis(3-aminopropyl)-tetramethyldisiloxane and employing tetramethylammonium hydroxide as the catalyst.…”

Section: Full Papermentioning

confidence: 99%

Synthesis of Amine and Epoxide Telechelic Siloxanes

Chakraborty

Soucek

2008

Macro Chemistry & Physics

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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

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Tetramethylammonium 3‐aminopropyl dimethylsilanolate—aminopropyl dimethylsilanolate—a new catalyst for the synthesis of high purity, high molecular weight α,ω‐bis(aminopropyl) polydimethylsiloxanes

Cited by 22 publications

References 8 publications

Novel materials based on silicone-acrylate copolymer networks

Novel materials based on silicone-acrylate copolymer networks

Telechelic siloxanes with hydrogen‐bonded polymerizable end groups. I. Liquid rubbers and elastomers

Synthesis of Amine and Epoxide Telechelic Siloxanes

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