Properties of polyisobutylene polyurethane block copolymers: 3. Hard segments based on 4,4′-dicyclohexylmethane diisocyanate (H12MDI) and butane diol

Speckhard, T. A.; Hwang, Kirk K. S.; Cooper, Stuart L.; Chang, Victor S. C.; Kennedy, Joseph P.

doi:10.1016/0032-3861(85)90058-8

Cited by 55 publications

(18 citation statements)

References 30 publications

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“…In the MDI-based samples this residual modulus is higher than in the samples based on the hydrogenated analogue again probably due to stiffer phenyl groups as compared with cyclohexyl groups. In the literature most of the reported comparisons between both the diisocyanates are related to linear polyurethanes and show contradictory results, the rubber modulus observed with H 12 MDI being either higher [19] or lower [20,21] than with MDI for otherwise similar samples. However, in these works the discrepancy can be probably related to a varying degree of microphase separation between soft and hard domains in both the types of samples; microphase separation was sometimes shown to be higher with H 12 MDI than with MDI [17].…”

Section: Discussionmentioning

confidence: 96%

Molecular dynamics in polyester- or polyether-urethane networks based on different diisocyanates

Okrasa

Czech

Boiteux

et al. 2008

Polymer

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Section: Discussionmentioning

confidence: 96%

Molecular dynamics in polyester- or polyether-urethane networks based on different diisocyanates

Okrasa

Czech

Boiteux

et al. 2008

Polymer

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“…2154 segments, that is, hard segment domains are more dispersed in soft segment and smaller amount of segregated hard segment domains are present compared to HDI based PU. [29][30][31] Additionally, the segregated portions of hard segment domains in PCL-HMDI-DTH are spherically oriented. Equally important is the dimension of the domains, specifically hard segment domains, which are in the nanoscale range.…”

Section: Phase Morphology Of Pusmentioning

confidence: 99%

Cell–material interactions on biphasic polyurethane matrix

Dicesare

Fox

Hill

et al. 2012

J Biomedical Materials Res

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Cell–matrix interaction is a key regulator for controlling stem cell fate in regenerative tissue engineering. These interactions are induced and controlled by the nanoscale features of extracellular matrix and are mimicked on synthetic matrices to control cell structure and functions. Recent studies have shown that nanostructured matrices can modulate stem cell behavior and exert specific role in tissue regeneration. In this study, we have demonstrated that nanostructured phase morphology of synthetic matrix can control adhesion, proliferation, organization and migration of human mesenchymal stem cells (MSCs). Nanostructured biodegradable polyurethanes (PU) with segmental composition exhibit biphasic morphology at nanoscale dimensions and can control cellular features of MSCs. Biodegradable PU with polyester soft segment and hard segment composed of aliphatic diisocyanates and dipeptide chain extender were designed to examine the effect polyurethane phase morphology. By altering the polyurethane composition, morphological architecture of PU was modulated and its effect was examined on MSC. Results show that MSCs can sense the nanoscale morphology of biphasic polyurethane matrix to exhibit distinct cellular features and, thus, signifies the relevance of matrix phase morphology. The role of nanostructured phases of a synthetic matrix in controlling cell–matrix interaction provides important insights for regulation of cell behavior on synthetic matrix and, therefore, is an important tool for engineering tissue regeneration.

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“…[9] The materials synthesized with the novel soft segment precursors provided by the Tudos group show a superior combination of high stiffness and high elongation relative to other materials prepared in this study and by others. [5,9,11] The barrier properties of these segmented, olefinic polyurethanes are also quite impressive. These elastomers were insoluble in all pure solvents tested, including aprotic solvents such as DMF and tetrahydrofuran (THF).…”

Section: Generalmentioning

confidence: 99%

“…[2,[5][6][7][8][9][10][11][12] More emphasis was placed on the latter, because of the commercial availability of butadiene polyols and problematic synthesis leading to inferior performance of the isobutylene-based systems. [10] The physical properties of the hydrogenated polybutadiene (PBD) urethanes, including mechanical performance, thermal transition temperatures, degree of phase separation, and transparency have been found to depend on a number of factors, including degree of hydrogenation [5], soft segment molecular weight [13], and synthesis conditions.…”

Section: Introductionmentioning

confidence: 99%

Transparent Barrier Urethanes Based on Polyethylene Soft Segments

Tan¹,

Napadensky²,

Sloan³

et al. 2000

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A series of polyurethane elastomers has been synthesized through copolymerization of polyethylene soft segments and methylene bis(4-phenylisocyanate) (MDI) and hydrogenated MDI (H12MDI). Polyethylene soft segments were prepared by the hydrogenation of polybutadiene polyols, either before or after copolymer synthesis. Polyols from three different suppliers were used as precursors and ranged in branch content from 15% to -90%. Flexible, transparent materials were produced. The mechanical and barrier properties of these urethanes were evaluated for comparison with the performance of traditional flexible barrier materials (e.g., butyl rubber). Solvent uptake and swelling measurements were used to evaluate barrier performance. Branch content in the soft segment was found to affect both mechanical properties and solvent resistance, with low branch content leading to superior performance. Solvent diffusion coefficients for the materials were in the 10" -cm /s range, comparable to those exhibited by flexible high barrier materials.

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Properties of polyisobutylene polyurethane block copolymers: 3. Hard segments based on 4,4′-dicyclohexylmethane diisocyanate (H12MDI) and butane diol

Cited by 55 publications

References 30 publications

Molecular dynamics in polyester- or polyether-urethane networks based on different diisocyanates

Molecular dynamics in polyester- or polyether-urethane networks based on different diisocyanates

Cell–material interactions on biphasic polyurethane matrix

Transparent Barrier Urethanes Based on Polyethylene Soft Segments

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