Linear Rheological Properties of Poly(Propylene Carbonate) with Different Molecular Weights

Yang, Lixin; Uneyama, Takashi; Masubuchi, Yuichi; Doi, Yuya

doi:10.1678/rheology.49.267

Cited by 6 publications

(14 citation statements)

References 27 publications

(59 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Due to practical limitations, we had four components for each case, and the molecular weight and the chain number fraction of each component were determined assuming a log-normal distribution. For the resultant set of molecules, the weight average number of entanglements, Z w = M w /M 0 , and the polydispersity index, Z w /Z n , are consistent with the target experiment [31,32]. For comparison, we also performed simulations for a monodisperse system.…”

Section: Model and Simulationssupporting

confidence: 65%

“…This carbonate polymer does not have bulky side groups, and it does not exhibit crystallization under the usual experimental conditions. Since no data for monodisperse PPC are available, we employed the dataset for polydisperse PPC melts [31,32], for which linear and nonlinear rheological properties have been reported. Although the polydispersity index is 1.3, which is not too large, we took account of its effects by using the multi-chain slip-link model.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of Elongational Viscosity of Entangled Poly (Propylene Carbonate) Melts by Primitive Chain Network Simulations

et al. 2022

Self Cite

View full text Add to dashboard Cite

It has been established that the elongational rheology of polymers depends on their chemistry. However, the analysis of experimental data has been reported for only a few polymers. In this study, we analyzed the elongational viscosity of poly (propylene carbonate) (PPC) melts in terms of monomeric friction via primitive chain network simulations. By incorporating a small polydispersity of materials, the linear viscoelastic response was semi-quantitatively reproduced. Owing to this agreement, we determined units of time and modulus to carry out elongational simulations. The simulation with constant monomeric friction overestimated elongational viscosity, whereas it nicely captured the experimental data if friction decreased with increasing segment orientation. To see the effect of chemistry, we also conducted the simulation for a polystyrene (PS) melt, which has a similar entanglement number per chain and a polydispersity index. The results imply that PPC and PS behave similarly in terms of the reduction of friction under fast deformations.

show abstract

Section: Model and Simulationssupporting

confidence: 65%

Section: Introductionmentioning

confidence: 99%

Analysis of Elongational Viscosity of Entangled Poly (Propylene Carbonate) Melts by Primitive Chain Network Simulations

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…Previously, LVE was reported for commercial PPC products 4,5) , but because of the uncertainty of the samples, i.e.,broadmolecularweightdistributionandunpurifiedlow molecular weight compounds, the basic LVE properties were not consistently reported. Recently, we prepared a series of PPC samples with relatively narrow molecular weight distributions, and reported that G N of PPC is 670 kPa 6) , which is considerably higher than that reported previously 5) .…”

Section: Rheologyisagoodmethodtounderstandtheflowandmentioning

confidence: 64%

“…Five PPC samples having different molecular weights with relatively narrow molecular weight distribution were used. All of them were prepared by precipitation fractionation of a commercial PPC as reported previously 6) . We have determined the absolute molecular weight by multi-angle light scattering (MALS), and the resultant value is different from that reported in the previous paper according to GPC with PS standards.…”

Section: Methodsmentioning

confidence: 99%

“…Figure 1 shows a direct comparison of the LVE data of PPC158k * andPS545k.Here,G′ and G″ in vertical axis are normalized by the plateau modulus G N (i.e., 670 kPa for PPC158k * and220kPaforPS545k),whileω in the horizontal axis is scaled by multiplying τ e , which represents the reciprocal of ω at the crosspoint of G′ and G″ at high frequency (i.e., τ e = 3.6 × 10 −5 sforPPC158k * at 100 °C, and 0.12 s for PS545kat130°C).TheentanglementnumberZ = M w /M e of PPC158k * is calculated as 27 using the entanglement molecular weight M e =5.9kg/mol 6) , whereas ZofPS545kiscalculated as 30 using M e = 18.0 kg/mol for PS 18) . In Fig.…”

Section: Linear Viscoelasticitymentioning

confidence: 99%

See 1 more Smart Citation

Nonlinear Shear and Elongational Rheology of Poly(propylene carbonate)

Yang

Uneyama

Masubuchi

et al. 2022

J. Soc. Rheol., Jpn

Self Cite

View full text Add to dashboard Cite

Nonlinear shear and elongational rheology of entangled poly(propylene carbonate) (PPC) melts having different molecular weights with relatively narrow molecular weight distribution are examined. In shear measurements, the PPCs exhibit a typical shear thinning behavior with stress overshoot at high shear rates. In the shear rate dependence of the steadystate viscosity, the PPCs do not violate the empirical Cox-Merz rule, which is known to be valid for many other entangled polymer melts. In uniaxial elongational measurements, the viscosity growth functions of the PPCs show a weak deviation from the linear viscoelastic (LVE) envelope to the higher side at the high Weissenberg number Wi d (= ͘ ετ d , where ͘ ε is the elongation rate and τ d is the characteristic disengagement time). The steady-state viscosity of the PPCs shows an elongational thinning as a function of ͘ ε −0.5 within an error. These results are similar to some other polymer melts such as polystyrene (PS). In addition, the normalized elongational viscosity growth functions of PPC and PS with a similar entanglement number Z, are compared. The PPC exhibits a similar viscosity growth curve to the PS at the same Wi d . This result suggests that the degree of the monomeric friction reduction originated from the stretch/orientation of PPC under fast elongational flowmightoccuratthesamelevelasPS.

show abstract

Elongational viscosity of poly(propylene carbonate) melts: tube-based modelling and primitive chain network simulations

2022

View full text Add to dashboard Cite

In fast elongational flows, linear polymer melts exhibit a monotonic decrease of the viscosity with increasing strain rate, even beyond the contraction rate of the polymer defined by the Rouse time. We consider two possible explanations of this phenomenon: (a) the reduction of monomeric friction and (b) the reduction of the tube diameter with increasing deformation leading to an Enhanced Relaxation of Stretch (ERS) on smaller length scales. (Masubuchi et al. (2022) reported Primitive Chain Network (PCN) simulations using an empirical friction reduction model depending on segmental orientation and could reproduce the elongational viscosity data of three poly(propylene carbonate) melts and a polystyrene melt. Here, we show that the mesoscopic tube-based ESR model (Wagner and Narimissa 2021) provides quantitative agreement with the same data set based exclusively on the linear-viscoelastic characterization and the Rouse time. From the ERS model, a parameter-free universal relation of monomeric friction reduction as a function of segmental stretch can be derived. PCN simulations using this friction reduction relation are shown to reproduce quantitatively the experimental data even without any fitting parameter. The comparison with results of the earlier PCN simulation results with friction depending on segmental orientation demonstrates that the two friction relations examined work equally well which implies that the physical mechanisms of friction reduction are still open for discussion.

show abstract

Linear Rheological Properties of Poly(Propylene Carbonate) with Different Molecular Weights

Cited by 6 publications

References 27 publications

Analysis of Elongational Viscosity of Entangled Poly (Propylene Carbonate) Melts by Primitive Chain Network Simulations

Analysis of Elongational Viscosity of Entangled Poly (Propylene Carbonate) Melts by Primitive Chain Network Simulations

Nonlinear Shear and Elongational Rheology of Poly(propylene carbonate)

Elongational viscosity of poly(propylene carbonate) melts: tube-based modelling and primitive chain network simulations

Contact Info

Product

Resources

About