Effect of Chain‐Length Dependence of Interaction Parameter on Spinodals for Polydisperse Polymer Blends

Du, Xiyan; Sun, Zhaoyan; An, Lijia

doi:10.1002/mats.200600002

Cited by 2 publications

(3 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One can see that if χ eff is assumed to be molecular weight independent, the UCSTs of PEP*-423/PEO-222(PEO-217) and PEP*-423/PEO-280 mixtures are overestimated by about 60 and 30 K, respectively, for both simulation and experimental data sets. Therefore, one can conclude that χ of the PEP/PEO mixtures exhibits a non-negligible molecular weight dependence and that this dependence stands in contrast to the general trend in earlier literature (decreasing χ with increasing molecular weight ,,, ).…”

Section: Resultscontrasting

confidence: 60%

Understanding the Molecular Weight Dependence of χ and the Effect of Dispersity on Polymer Blend Phase Diagrams

et al. 2018

View full text Add to dashboard Cite

Gibbs ensemble Monte Carlo simulations and cloud point measurements were performed to understand the molecular weight dependence of χ and the effect of dispersity on the phase behavior of polymer mixtures. Oligomeric blends consisting of poly(ethylene-alt-propylene) (PEP) and poly(ethylene oxide) dimethyl ether (PEO) were used as the model systems. First, the molecular weight dependence of χ for PEP/PEO mixtures was studied using simulations and experiments for PEP/PEO mixtures with various molecular weights. An empirical model with a single adjustable parameter k ij is used to quantify this molecular weight dependence, and it allows for the accurate prediction of χ of PEP/PEO mixtures with arbitrary molecular weights. Second, the effects of molecular weight distribution (MWD) and dispersity (Đ) of PEO on the PEP/PEO phase diagram were investigated via both simulations and experiments. When PEO is relatively monodisperse (Đ < 1.2), the phase diagram is found to be insensitive to either MWD or Đ, despite differentiation in molecular partitioning observed from simulations. However, the coexistence curve for mixtures containing PEO with a bimodal distribution and a large dispersity (Đ = 1.76) differs dramatically from that for mixtures containing low-dispersity PEO, which suggests that the former mixture can no longer be treated as a binary system. Furthermore, structural analysis was performed from simulation trajectories to probe microscopic heterogeneity and aggregation behavior in the liquid phases. The results in this work permit the accurate prediction of χ and the phase diagram of disperse binary polymeric mixtures.

show abstract

Section: Resultscontrasting

confidence: 60%

Understanding the Molecular Weight Dependence of χ and the Effect of Dispersity on Polymer Blend Phase Diagrams

et al. 2018

View full text Add to dashboard Cite

show abstract

“…With respect to the polydisperse polymer blends, the effect of polydispersity on the spinodal in a polymer blend was studied by Du et al [26] In addition, the effect of polydispersity on the cloud curve in partially miscible polymer blends of polyethylene (PE)/isotactic poly-(propylene) (iPP) with the UCST phenomenon was computed by Lo et al [27] They concluded that the system with lower polydispersity had a narrower spinodal curve, indicating higher miscibility. Polydispersity effects in the thermodynamics and dynamics at the early stages of the phase separation in incompatible monodisperse A-monodisperse B and polydisperse A-monodisperse B polymer blends were studied by Huang and de la Cruz.…”

Section: Introductionmentioning

confidence: 98%

“…[19] Also, the relaxation time of the shortest chains increases with the concentration of long chains. [21] Available research about the effect of polydispersity on the phase behavior of polymer systems is mainly focused on polymer solutions, [15,17,[22][23][24][25] polymer blends, [26][27][28][29] and block copolymers. [30][31][32] Because a clear understanding of the effect of polydispersity on the phase behavior of polymer solutions is essential to investigate the effect of polydispersity on the phase behavior of polymer blends, the polydisperse polymer solution systems have been researched abundantly.…”

Section: Introductionmentioning

confidence: 99%

Effect of Polydispersity on the Phase Behavior of Polystyrene (PS)/Poly (Vinyl Methyl Ether) (PVME)

Huang

Yang

2011

Journal of Macromolecular Science, Part B

View full text Add to dashboard Cite

The thermodynamics and kinetics of phase separation in partially miscible blends of poly (vinyl methyl ether) (PVME) and two kinds of polystyrene (PS) with the same weight average molecular weight but different polydispersity were studied. The miscibility of PS/PVME with the monodisperse PS was better than that of PS/PVME with the polydisperse PS. Different morphology was observed for the two kinds of PS/PVME (10/90) blends during the nonisothermal phase separation process. The blend with monodisperse PS presented a co-continuous structure while the blend with polydisperse PS presented a viscoelastic phase separated network structure at a quench depth of 29 • C. With increase of the heating rate, the increase of cloud point of PS/PVME (30/70) with polydisperse PS was smaller than that of PS/PVME (30/70) with monodisperse PS. During the isothermal phase separation of the critical composition (20/80) of PS/PVME with a quench depth of 30 • C, it was found that the phase morphology of the two kinds of blends was nearly the same at the early stage of phase separation. However, as the dispersed phase, an approximately spherical droplet structure was observed in the blend with monodisperse PS at the late stage of phase separation, which did not appear in the blend with polydisperse PS.

show abstract

Effect of Chain‐Length Dependence of Interaction Parameter on Spinodals for Polydisperse Polymer Blends

Cited by 2 publications

References 21 publications

Understanding the Molecular Weight Dependence of χ and the Effect of Dispersity on Polymer Blend Phase Diagrams

Understanding the Molecular Weight Dependence of χ and the Effect of Dispersity on Polymer Blend Phase Diagrams

Effect of Polydispersity on the Phase Behavior of Polystyrene (PS)/Poly (Vinyl Methyl Ether) (PVME)

Contact Info

Product

Resources

About