Bulk and shear rheology of a symmetric three‐arm star polystyrene

Guo, Jie; Grassia, Luigi; Simon, Sindee L.

doi:10.1002/polb.23113

Cited by 32 publications

(31 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To the best of our knowledge, there is no research on measuring the sound velocity and longitudinal loss tangent of XHDPE and XLDPE. However, study on the bulk rheology of linear and branched PS [14] and crosslinked polycyanurate of different crosslinked density [15] shows that there is insignificant dependence of bulk rheological properties on chain architecture of polymer, i.e. linear, branched chain and crosslinked network.…”

Section: Resultsmentioning

confidence: 99%

Comparison between decrosslinking of crosslinked high and low density polyethylenes via ultrasonically aided extrusion

Isayev¹,

Huang²

2016

AIP Conference Proceedings

View full text Add to dashboard Cite

Stress growth and relaxation of dendritically branched macromolecules in shear and uniaxial extension Journal of Rheology 61, 35 (2017) Abstract. Among various crosslinked plastics, recycling of crosslinked polyethylenes is of a great importance due to the presence of a three-dimensional network. To solve this problem, novel environmentally friendly technologies for decrosslinking of the crosslinked polymers are developed based on ultrasonically assisted single (SSE) and twin screw (TSE) extruders. In particular, decrosslinking of peroxide crosslinked high-density polyethylene (XHDPE) and low-density polyethylene (XLDPE) by means of an ultrasonic SSE and TSE is investigated. Barrel pressure, die pressure and ultrasonic power consumption during extrusion are recorded. Swelling, rheological, thermal analysis and tensile tests are used to elucidate the structure-property relationships of decrosslinked XHDPE and XLDPE. The frequency dependencies of the storage and loss moduli, complex viscosity and tangent loss of XHDPE, XLDPE and their decrosslinked networks are described by the post critical gel model with its parameters correlated with gel fraction and crosslink density. The dynamic, thermal and tensile properties of the decrosslinked XHDPE and XLDPE are greatly affected by the type of preferential bond breakage. It was found that the decrosslinking of XLDPE is more difficult than that of XHDPE. An analysis based on the Horikx function reveals a highly preferential breakage of crosslinks during decrosslinking of XHDPE. In contrast to decrosslinking of XHDPE, the presence of long-chain branching in XLDPE is found to lead to the breakage of its main chains during decrosslinking. An improvement and a reduction in mechanical properties of decrosslinked XHDPE and XLDPE are, respectively, observed in comparison with those of virgin XHDPE and XLDPE.

show abstract

Section: Resultsmentioning

confidence: 99%

Comparison between decrosslinking of crosslinked high and low density polyethylenes via ultrasonically aided extrusion

Isayev¹,

Huang²

2016

AIP Conference Proceedings

View full text Add to dashboard Cite

show abstract

“…To the best of our knowledge, there is no research on measuring the sound velocity and longitudinal loss tangent of XHDPE and XLDPE. However, study on the bulk rheology of linear and branched PS [23] and crosslinked polycyanurate of different crosslinked density [24] shows that there is insignificant dependence of bulk rheological…”

Section: Resultsmentioning

confidence: 99%

Comparison between decrosslinking of crosslinked high and low density polyethylenes via ultrasonically aided extrusion

Huang

Isayev

2015

Polymer

View full text Add to dashboard Cite

Please cite this article as: Huang K, Isayev AI, Comparison between decrosslinking of crosslinked high and low density polyethylenes via ultrasonically aided extrusion, Polymer (2015), AbstractAmong various polymer wastes, management of crosslinked plastics is a major environmental problem requiring a solution. Among various crosslinked plastics, recycling of crosslinked polyethylenes is of a great importance due to the presence of a three-dimensional network. To solve this problem, novel environmentally friendly technologies for decrosslinking of the crosslinked polymers are developed based on ultrasonically assisted single (SSE) and twin screw (TSE) extruders. In particular, decrosslinking of peroxide crosslinked high-density polyethylene (XHDPE) and low-density polyethylene (XLDPE) by means of an ultrasonic SSE and TSE is investigated. Barrel pressure, die pressure and ultrasonic power consumption during extrusion are recorded. Swelling, rheological, thermal analysis and tensile tests are used to elucidate the structure-property relationships of decrosslinked XHDPE and XLDPE. The frequency dependencies of the storage and loss moduli, complex viscosity and tangent loss of XHDPE, XLDPE and their decrosslinked networks are described by the post critical gel model with its parameters correlated with gel fraction and crosslink density. The dynamic, thermal and tensile properties of the decrosslinked XHDPE and XLDPE are greatly affected by the type of preferential bond breakage. It was found that the decrosslinking of XLDPE is more difficult than that of XHDPE. An analysis based on the Horikx function reveals a highly preferential breakage of crosslinks during decrosslinking of XHDPE. In contrast to decrosslinking of XHDPE, the presence of long-chain branching in XLDPE is found to lead to the breakage of its main chains during decrosslinking. An improvement and a reduction in mechanical properties of decrosslinked XHDPE and XLDPE are, respectively, observed in comparison with those of virgin XHDPE and XLDPE. Such differences in behavior are due to the occurrence of a highly preferential breakage of crosslinks in XHDPE and the breakage of main chains in XLDPE during ultrasonic decrosslinking. Graphic AbstractStress-strain curves of HDPE, LDPE, XHDPE and XLDPE (a) and decrosslinked XHDPE (b) and XLDPE (c) by SSE and TSE with and without ultrasonic treatment.

show abstract

“…References [111] [113] [114] [115] are recent examples of experimental viscoelastic PR characterizations. These references, as well as [1] and [87] [88] [90], include extensive bibliographies that are not repeated here.…”

Section: ) Contributions Of the Loading Phase In Determining Materiamentioning

confidence: 99%

Elastic and Viscoelastic Poisson’s Ratios: The Theoretical Mechanics Perspective

Hilton¹

2017

MSA

View full text Add to dashboard Cite

A recent review publication presented an extensive and comprehensive assessment of the phenomenological relations of Poisson's ratios (PRs) to the behavior and responses of contemporary materials under specific loading conditions. The present review and analysis paper is intended as a theoretical mechanics complement covering mathematical and physical modeling of a single original elastic and of six time and process (i.e. path and stress) dependent viscoelastic PR definitions as well as a seventh special path independent one. The implications and consequences of such models on material characterization are analyzed and summarized. Indeed, PRs based on experimentally obtained 2-D strains under distinct creep and/or relaxation processes exhibit radically different time responses for identical material specimen. These results confirm the PR's implicit path dependence in addition to their separate intrinsic time reliance. Such non-uniqueness of viscoelastic PRs renders them unsuitable as universal material descriptors. Analytical formulations and experimental measurements also examine the physical impossibility of instantaneously achieving time independent loads or strains or their rates thus making certain PR definitions based on constant state variables, while mathematically valid, physically unrealistic and unachievable. A newly developed theoretical/experimental protocol for the determination of the time when loading patterns reach stead-state conditions based on strain accelerations demonstrates the capability to measure this time from experimental data. Due to the process dependent PRs, i.e. stress and stress history paths, the non-existence of a unique viscoelastic PR and of a universal elastic-viscoelastic correspondence principle or analogy (EVCP) in terms of PRs is demonstrated. Additionally and independently, the required double convolution integral construction of linear viscoelastic constitutive relations with the inclusion of PRs is cumbersome analytically and computationally needlessly highly CPU intensive. Furthermore, there is no theoretical fundamental hint as to what loading path is required to produce a unique universal viscoelastic PR definition necessary for formulating a PR based constitutive relation or an EVCP protocol. The analysis associated with an additional Class VII viscoelastic PR establishes it as a universal representation which is loading path and strain independent while still remaining time dependent. This Class PR can be the one used if it is desired to express constitutive relations in terms of PRs, subject to the caveat applying to all PR Classes regarding the CPU intensiveness in the time space due to triple product and double convolution integral constitutive relations. However, the use PRs is unnecessary since any set of material behavior can be uniquely and completely defined in terms of only moduli and/or compliances. The mathematical model of instantaneous initial loading paths, based on Heaviside functions, is examined in detail and shown to lead to infinite vel...

show abstract

Bulk and shear rheology of a symmetric three‐arm star polystyrene

Cited by 32 publications

References 52 publications

Comparison between decrosslinking of crosslinked high and low density polyethylenes via ultrasonically aided extrusion

Comparison between decrosslinking of crosslinked high and low density polyethylenes via ultrasonically aided extrusion

Comparison between decrosslinking of crosslinked high and low density polyethylenes via ultrasonically aided extrusion

Elastic and Viscoelastic Poisson’s Ratios: The Theoretical Mechanics Perspective

Contact Info

Product

Resources

About