Domain structure and time‐dependent properties of a crosslinked urethane elastomer

Lagasse, R. R.

doi:10.1002/app.1977.070210917

Cited by 63 publications

(18 citation statements)

References 4 publications

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“…Its average functionality is 2.38 and its chemical structure consists of 60. 8 Low molecular weight aliphatic diols included the following homologous series: ethylene glycol (EC), 1,3-propandiol (PrD), 1,4-butandiol (BUD), 1,5-pentandiol (PeD), 1,6-hexandiol (HeD), and 1,lO-decadiol (DeD).…”

Section: Experimental Materialsmentioning

confidence: 99%

Polyurethane elastomers containing polybutadiene and aliphatic diols: Polymerization and structure

Cohen

Siegmann

Narkis

1987

Polymer Engineering & Sci

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The effect of aliphatic diols on the polymerization and network formation of polyurethane elastomers containing hydroxyl terminated polybutadiene and three different diisocyanates was studied. The polymerization/curing progress was followed by viscosity measurements, IR spectroscopy, swelling, extraction, and hardness measurements. The resulting networks were characterized by swelling experiments. The type of diisocyanate and the diol chain length were found to have significant effects on the reacting mixtures throughout the polymerization course. The effects observed included the phase structure of the reacting mixtures, the reaction rate, the crosslink density, and the physical interactions.

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Section: Experimental Materialsmentioning

confidence: 99%

Polyurethane elastomers containing polybutadiene and aliphatic diols: Polymerization and structure

Cohen

Siegmann

Narkis

1987

Polymer Engineering & Sci

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“…The hard segments aggregate to form glassy or crystalline hard-segment domains in the soft matrix. 1 The main factors influencing the phase separation include the type and segment length, crystallizability, tendency for soft segment-hard segment hydrogen bonding, sample composition, and history of the sample preparation. [2][3][4] Hard-segment domains act as physical junction points, greatly improving mechanical properties of PUR networks.…”

Section: Introductionmentioning

confidence: 99%

Polybutadiene-based polyurethanes with controlled properties: preparation and characterization

Špírková

Matějka

Hlavatá

et al. 2000

J. Appl. Polym. Sci.

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A series of segmented polyurethanes was prepared from the new commercial product KRASOL LBH (linear liquid polybutadiene terminated with secondary hydroxy groups), aromatic diisocyanates, and an aliphatic low-molecular-weight diol. Three types of networks were prepared, with the nature of the crosslinks varied from purely chemical to physical, with a continuous transition to "combined" networks containing both crosslink types. Potassium 2-ethyl hexanoate was used as a catalyst of the in situ formation of trifunctional isocyanurate groups (by cyclotrimerization of isocyanate groups). It was confirmed that mechanical, thermal, and swelling properties are considerably influenced by the ratio of chemical to physical crosslink concentration. The best balance of stressstrain properties was obtained for "combined" networks at a NCO-OH molar ratio of 1.10 when only a few chemical crosslinks are present in predominantly physically crosslinked networks. The presence of thermally stable isocyanurate groups mainly influences the storage shear modulus at elevated temperatures. Small-angle X-ray scattering confirmed the two-phase structure of polyurethanes with a periodicity of 6 -8 nm.

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“…[7][8][9][10][11][12][13][14][15][16][17][18][19] erty performances of HTPB show surprising utilBut the HTPB-based PUs generally exhibit infeity in many fields. [1][2][3] HTPB-based PUs have been rior mechanical properties compared to the conused for gas separation research because of their ventional PUs.…”

Section: Introductionmentioning

confidence: 99%

Tensile property of modified hydroxyl-terminated polybutadiene-based polyurethanes

Huang

Lai

1997

J. Appl. Polym. Sci.

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Modified hydroxyl-terminated polybutadiene (HTPB)-based polyurethanes (PUs) were prepared by three different processes: crosslinkage of the soft segment, complexation of the hard segment, and the interpenetrating network (IPN). Crosslinked PU films were prepared by the addition of a crosslinking agent of divinylbenzene (DVB) to the 4,4 -dicyclohexylmethane diisocyanate (H 12 MDI) and 1,4-butanediol (1,4-BD)-based PUs. The ionic polymer was prepared by adding N-methyldiethanolamine (MDEA), which possesses tertiary amine used as chain extender, to the HTPB-H 12 MDI-based PUs and then complexed by cupric chloride with MDEA. An IPN was formed by the introduction of 4-vinylpyridine (4-VP) to the benzoyl peroxide (BPO)-crosslinked HTPB-H 12 MDI-1,4BD-based PUs. FTIR was utilized to identify the segregation between hard and soft segments and structure change, which affects the tensile properties. The change of the glass transition temperature was detected by DSC, which can be used to manifest the modified PUs. Thermal decomposition behaviors conducted by TGA were used to investigate the formation of an IPN. The hydrogen-bonding index (HBI), frequency difference, and shift as a measure of the phase segregation and the average strength of the interpolymer hydrogen bonds were utilized to study the intermolecular interaction and tensile property of the prepared PUs. The effect of the hard-segment content, DVB content, amount of cupric ion, and 4-VP content on the tensile property were investigated. The stress was largely increased by the modification of PUs, while the strain still remains an appreciable value compared with that of unmodified PUs.

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Domain structure and time‐dependent properties of a crosslinked urethane elastomer

Cited by 63 publications

References 4 publications

Polyurethane elastomers containing polybutadiene and aliphatic diols: Polymerization and structure

Polyurethane elastomers containing polybutadiene and aliphatic diols: Polymerization and structure

Polybutadiene-based polyurethanes with controlled properties: preparation and characterization

Tensile property of modified hydroxyl-terminated polybutadiene-based polyurethanes

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