Uniform patchy and hollow rectangular platelet micelles from crystallizable polymer blends

We apply molecular dynamics (MD) simulations to investigate crystal nucleation in incompatible polymer blends under deep supercooling conditions. Simulations of isothermal nucleation are performed for phase-separated blends with different degrees of incompatibility. In weakly segregated blends, slow and incompatible chains in crystallizable polymer domains can significantly hinder the crystal nucleation and growth. When a crystallizable polymer is blended with a more mobile species in interfacial regions, enhanced molecular mobility leads to the fast growth of crystalline order. However, the incubation time remains the same as that in pure samples. By inducing anisotropic alignment near the interfaces of strongly segregated blends, phase separation also promotes crystalline order to grow near interfaces between different polymer domains.

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Morphology Development Associated With Polymer Blends

MRS Proceedings ◽

10.1557/proc-856-bb11.3 ◽

2004 ◽

Vol 856 ◽

Author(s):

Tomoko Hashida ◽

Ying Hua ◽

Shaw Ling Hsu ◽

Charles W. Paul

Keyword(s):

Polymer Blends ◽

Degree Of Crystallinity ◽

Similar Chemical ◽

Crystallizable Polymer ◽

Morphology Development ◽

Morphological Differences ◽

Chemical Distribution ◽

Poly Propylene ◽

First Time

ABSTRACTMorphology development of crystallizable polymer blends has been investigated using optical microscopy, thermal analysis, and vibrational spectroscopy. The blends studied involve crystallizable polyesters of poly(hexamethylene adipate) (PHMA) and poly(hexamethylene sebacate) (PHMS) and non-crystallizable poly(propylene glycol) (PPG). Although these polyesters possess similar chemical structure, they exhibit different phase behavior. Ternary blends including a high glass transition temperature (Tg) component were also studied. Crystallization kinetics in these blends was obtained utilizing Fourier transform infrared spectroscopy. Micro-Raman spectroscopy capable of achieving high spatial resolution (1 μm2) revealed detailed morphological differences in the phase-separated structures. This technique made possible for the first time characterization of the chemical composition of the blends and distribution of crystallites. The role of the third relative immobile component significantly changed both chemical distribution and the degree of crystallinity.

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Pressure-volume-temperature and excess molar volume prediction of amorphous and crystallizable polymer blends by equation of state

Chinese Journal of Chemical Engineering ◽

10.1016/j.cjche.2013.12.002 ◽

2015 ◽

Vol 23 (3) ◽

pp. 541-551 ◽

Cited By ~ 1

Author(s):

Fakhri Yousefi ◽

Hajir Karimi ◽

Maryam Gomar

Keyword(s):

Equation Of State ◽

Polymer Blends ◽

Molar Volume ◽

Excess Molar Volume ◽

Crystallizable Polymer

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Uniform “Patchy” Platelets by Seeded Heteroepitaxial Growth of Crystallizable Polymer Blends in Two Dimensions

Journal of the American Chemical Society ◽

10.1021/jacs.6b12503 ◽

2017 ◽

Vol 139 (12) ◽

pp. 4409-4417 ◽

Cited By ~ 39

Author(s):

Ali Nazemi ◽

Xiaoming He ◽

Liam R. MacFarlane ◽

Robert L. Harniman ◽

Ming-Siao Hsiao ◽

...

Keyword(s):

Polymer Blends ◽

Two Dimensions ◽

Heteroepitaxial Growth ◽

Crystallizable Polymer

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Polymer Morphology Revealed by Staining Techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098204 ◽

1981 ◽

Vol 39 ◽

pp. 340-341

Author(s):

A. C. Reimschuessel ◽

V. Kramer

Keyword(s):

Polymer Melt ◽

Nylon 6 ◽

Morphological Features ◽

Negative Staining ◽

Polymer Morphology ◽

Crystallizable Polymer ◽

Staining Techniques ◽

Long Chain

Staining techniques can be used for either the identification of different polymers or for the differentiation of specific morphological domains within a given polymer. To reveal morphological features in nylon 6, we choose a technique based upon diffusion of the staining agent into accessible regions of the polymer.When a crystallizable polymer - such as nylon 6 - is cooled from the melt, lamellae form by chainfolding of the crystallizing long chain macromolecules. The regions between adjacent lamellae represent the less ordered amorphous domains into which stain can diffuse. In this process the lamellae will be “outlined” by the dense stain, giving rise to contrast comparable to that obtained by “negative” staining techniques.If the cooling of the polymer melt proceeds relatively slowly - as in molding operations - the lamellae are usually arranged in a radial manner. This morphology is referred to as spherulitic.

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Integration of Core-Edge Spectroscopy Methods for the Study of Polymers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016323x ◽

1996 ◽

Vol 54 ◽

pp. 154-155

Author(s):

E. G. Rightor

Keyword(s):

Excited State ◽

Polymer Blends ◽

Gas Phase ◽

Spatial Resolution ◽

High Spatial Resolution ◽

Electronic States ◽

Core Electron ◽

Bulk Solids ◽

Development Application

Core edge spectroscopy methods are versatile tools for investigating a wide variety of materials. They can be used to probe the electronic states of materials in bulk solids, on surfaces, or in the gas phase. This family of methods involves promoting an inner shell (core) electron to an excited state and recording either the primary excitation or secondary decay of the excited state. The techniques are complimentary and have different strengths and limitations for studying challenging aspects of materials. The need to identify components in polymers or polymer blends at high spatial resolution has driven development, application, and integration of results from several of these methods.

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A quantitative image analysis method for the determination of cocontinuity in polymer blends

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100150307 ◽

1993 ◽

Vol 51 ◽

pp. 894-895

Author(s):

William A. Heeschen

Keyword(s):

Image Analysis ◽

Polymer Blends ◽

Quantitative Measurement ◽

Morphological Evolution ◽

Phase Ratio ◽

Irregular Shapes ◽

Quantitative Image ◽

Discrete Domains ◽

A Domains

Two new morphological measurements based on digital image analysis, CoContinuity and CoContinuity Balance, have been developed and implemented for quantitative measurement of morphology in polymer blends. The morphology of polymer blends varies with phase ratio, composition and processing. A typical morphological evolution for increasing phase ratio of polymer A to polymer B starts with discrete domains of A in a matrix of B (A/B < 1), moves through a cocontinuous distribution of A and B (A/B ≈ 1) and finishes with discrete domains of B in a matrix of A (A/B > 1). For low phase ratios, A is often seen as solid convex particles embedded in the continuous B phase. As the ratio increases, A domains begin to evolve into irregular shapes, though still recognizable as separate domains. Further increase in the phase ratio leads to A domains which extend into and surround the B phase while the B phase simultaneously extends into and surrounds the A phase.

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