Thermal and viscoelastic structure-property relationships of model comb-like poly(n-butyl methacrylate)

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dc.contributor.authorVosloo, J.J.
dc.contributor.authorvan Zyl, A.J.P.
dc.contributor.authorNicholson, T.M.
dc.contributor.authorSanderson, R.D.
dc.contributor.authorGilbert, R.G.
dc.contributor.authorVosloo, J.J.
dc.contributor.authorvan Zyl, A.J.P.
dc.contributor.authorNicholson, T.M.
dc.contributor.authorSanderson, R.D.
dc.contributor.authorGilbert, R.G.
dc.date.accessioned2011-05-15T16:02:16Z
dc.date.accessioned2011-05-15T16:02:16Z
dc.date.available2011-05-15T16:02:16Z
dc.date.available2011-05-15T16:02:16Z
dc.date.issued2007
dc.date.issued2007
dc.descriptionA range of comb polymers of poly(n-butyl methacrylate), where the degree of polymerization (DP) of both the backbone and branches was controlled using RAFT-mediated free-radical polymerization, was synthesized using the method of Vosloo et al. [Macromolecules 2004;37: 2371]. Individual architectural parameters (branch length, branch number and DP of the comb backbone) of these relatively monodisperse samples were systematically varied in order to study the impact of each structural parameter on the thermal and rheological properties of the resulting comb polymers. Differential scanning calorimetry showed lower glass transition temperatures for the comb polymers compared to the original linear backbones. There were negligible differences in glass transition temperatures between comb polymers containing branches of different lengths, and between comb polymers containing backbones of narrow and of broad molecular weight distributions. These observations suggest that because the comb polymers are very tightly spaced, the branches act in the same way as long chain polyBMA. Viscoelastic properties of the comb polymers were investigated using dynamic mechanical analysis, using time-temperature superposition to extend the rheological data over a wide frequency range. Major differences in the viscoelastic responses of the original linear backbones and the comb polymers were observed, which were explained in terms of arm retraction/relaxation leading to tube dilation. All comb polymers showed viscoelastic responses that are characteristic of combs, but differences in responses due to changes in branch length and branch number were difficult to detect. This was mainly due to the relatively high number of branches, whose retractions occurred over a broad frequency range, and thus dominated the observed changes in moduli, thereby possibly masking subtle differences in responses. © 2006 Elsevier Ltd. All rights reserved.
dc.description.abstractA range of comb polymers of poly(n-butyl methacrylate), where the degree of polymerization (DP) of both the backbone and branches was controlled using RAFT-mediated free-radical polymerization, was synthesized using the method of Vosloo et al. [Macromolecules 2004;37: 2371]. Individual architectural parameters (branch length, branch number and DP of the comb backbone) of these relatively monodisperse samples were systematically varied in order to study the impact of each structural parameter on the thermal and rheological properties of the resulting comb polymers. Differential scanning calorimetry showed lower glass transition temperatures for the comb polymers compared to the original linear backbones. There were negligible differences in glass transition temperatures between comb polymers containing branches of different lengths, and between comb polymers containing backbones of narrow and of broad molecular weight distributions. These observations suggest that because the comb polymers are very tightly spaced, the branches act in the same way as long chain polyBMA. Viscoelastic properties of the comb polymers were investigated using dynamic mechanical analysis, using time-temperature superposition to extend the rheological data over a wide frequency range. Major differences in the viscoelastic responses of the original linear backbones and the comb polymers were observed, which were explained in terms of arm retraction/relaxation leading to tube dilation. All comb polymers showed viscoelastic responses that are characteristic of combs, but differences in responses due to changes in branch length and branch number were difficult to detect. This was mainly due to the relatively high number of branches, whose retractions occurred over a broad frequency range, and thus dominated the observed changes in moduli, thereby possibly masking subtle differences in responses. © 2006 Elsevier Ltd. All rights reserved.
dc.description.abstractA range of comb polymers of poly(n-butyl methacrylate), where the degree of polymerization (DP) of both the backbone and branches was controlled using RAFT-mediated free-radical polymerization, was synthesized using the method of Vosloo et al. [Macromolecules 2004;37: 2371]. Individual architectural parameters (branch length, branch number and DP of the comb backbone) of these relatively monodisperse samples were systematically varied in order to study the impact of each structural parameter on the thermal and rheological properties of the resulting comb polymers. Differential scanning calorimetry showed lower glass transition temperatures for the comb polymers compared to the original linear backbones. There were negligible differences in glass transition temperatures between comb polymers containing branches of different lengths, and between comb polymers containing backbones of narrow and of broad molecular weight distributions. These observations suggest that because the comb polymers are very tightly spaced, the branches act in the same way as long chain polyBMA. Viscoelastic properties of the comb polymers were investigated using dynamic mechanical analysis, using time-temperature superposition to extend the rheological data over a wide frequency range. Major differences in the viscoelastic responses of the original linear backbones and the comb polymers were observed, which were explained in terms of arm retraction/relaxation leading to tube dilation. All comb polymers showed viscoelastic responses that are characteristic of combs, but differences in responses due to changes in branch length and branch number were difficult to detect. This was mainly due to the relatively high number of branches, whose retractions occurred over a broad frequency range, and thus dominated the observed changes in moduli, thereby possibly masking subtle differences in responses. © 2006 Elsevier Ltd. All rights reserved.
dc.description.versionArticle
dc.description.versionArticle
dc.identifier.citationPolymer
dc.identifier.citation48
dc.identifier.citation1
dc.identifier.citationPolymer
dc.identifier.citation48
dc.identifier.citation1
dc.identifier.issn323861
dc.identifier.issn323861
dc.identifier.other10.1016/j.polymer.2006.11.024
dc.identifier.other10.1016/j.polymer.2006.11.024
dc.identifier.urihttp://hdl.handle.net/10019.1/12396
dc.identifier.urihttp://hdl.handle.net/10019.1/12396
dc.subjectConformations; Differential scanning calorimetry; Free radical polymerization; Glass transition; Thermodynamic stability; Viscoelasticity; Degree of polymerization (DP); Rheological properties; Structural parameters; Viscoelastic properties; Organic polymers; glass transition temperature; molecular weight; polyacrylate; polymerization; rheology; structural property; synthesis; thermal property; viscoelasticity
dc.subjectConformations
dc.subjectDifferential scanning calorimetry
dc.subjectFree radical polymerization
dc.subjectGlass transition
dc.subjectThermodynamic stability
dc.subjectViscoelasticity
dc.subjectDegree of polymerization (DP)
dc.subjectRheological properties
dc.subjectStructural parameters
dc.subjectViscoelastic properties
dc.subjectOrganic polymers
dc.subjectglass transition temperature
dc.subjectmolecular weight
dc.subjectpolyacrylate
dc.subjectpolymerization
dc.subjectrheology
dc.subjectstructural property
dc.subjectsynthesis
dc.subjectthermal property
dc.subjectviscoelasticity
dc.titleThermal and viscoelastic structure-property relationships of model comb-like poly(n-butyl methacrylate)
dc.titleThermal and viscoelastic structure-property relationships of model comb-like poly(n-butyl methacrylate)
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