Phase Evolution Theory for Polymer Blends with Extreme Chemical Dispersity: Parameterization of DDFT Simulations and Application to Poly(propylene) Impact Copolymers

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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Simulation of dispersed phase evolution for immiscible polymer blends in injection molding

Engineering Computations ◽

10.1108/ec-03-2017-0093 ◽

2017 ◽

Vol 34 (7) ◽

pp. 2311-2329 ◽

Cited By ~ 2

Author(s):

Dan Chen ◽

Fen Liu ◽

Yi Zhang ◽

Yun Zhang ◽

Huamin Zhou

Keyword(s):

Injection Molding ◽

Flow Field ◽

Polymer Blends ◽

Phase Evolution ◽

Dispersed Phase ◽

Deformation Model ◽

Immiscible Polymer Blends ◽

Content Type ◽

Immiscible Polymer ◽

Numerical Strategy

Purpose The numerical simulation of dispersed-phase evolution in injection molding process of polymer blends is of great significance in both adjusting material microstructure and improving performances of the final products. This paper aims to present a numerical strategy for the simulation of dispersed-phase evolution for immiscible polymer blends in injection molding. Design/methodology/approach First, the dispersed-phase modeling is discussed in detail. Then the Maffettone–Minale model, affine deformation model, breakup model and coalescence statistical model are chosen for the dispersed-phase evolution. A general coupled model of microscopic morphological evolution and macroscopic flow field is constructed. Besides, a stable finite element simulation strategy based on pressure-stabilizing/Petrov–Galerkin/streamline-upwind/Petrov–Galerkin method is adopted for both scales. Findings Finally, the simulation results are compared and evaluated with the experimental data, suggesting the reliability of the presented numerical strategy. Originality/value The coupled modeling of dispersed-phase and complex flow field during injection molding and the tracing and simulation of droplet evolution during the whole process can be achieved.

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Risperidone Controlled Release Microspheres Based on Poly(Lactic Acid)-Poly(Propylene Adipate) Novel Polymer Blends Appropriate for Long Acting Injectable Formulations

Pharmaceutics ◽

10.3390/pharmaceutics10030130 ◽

2018 ◽

Vol 10 (3) ◽

pp. 130 ◽

Cited By ~ 5

Author(s):

Stavroula Nanaki ◽

Panagiotis Barmpalexis ◽

Alexandros Iatrou ◽

Evi Christodoulou ◽

Margaritis Kostoglou ◽

...

Keyword(s):

Lactic Acid ◽

Controlled Release ◽

Drug Release ◽

Polymer Blends ◽

Solvent Evaporation ◽

Poly Lactic Acid ◽

Solvent Evaporation Method ◽

Evaporation Method ◽

Long Acting ◽

Poly Propylene

The present study evaluates the preparation of risperidone controlled release microspheres as appropriate long-acting injectable formulations based on a series of novel biodegradable and biocompatible poly(lactic acid)–poly(propylene adipate) (PLA/PPAd) polymer blends. Initially, PPAd was synthesized using a two-stage melt polycondensation method (esterification and polycondensation) and characterized by 1H-NMR, differential scanning calorimetry (DSC), and powder X-ray diffraction (XRD) analyses. DSC and XRD results for PLA/PPAd blends (prepared by the solvent evaporation method) showed that these are immiscible, while enzymatic hydrolysis studies performed at 37 °C showed increased mass loss for PPAd compared to PLA. Risperidone-polyester microparticles prepared by the oil–water emulsification/solvent evaporation method showed smooth spherical surface with particle sizes from 1 to 15 μm. DSC, XRD, and Fourier-transformed infrared (FTIR) analyses showed that the active pharmaceutical ingredient (API) was dispersed in the amorphous phase within the polymer matrices, whereas in vitro drug release studies showed risperidone controlled release rates in all PLA/PPAd blend formulations. Finally, statistical moment analysis showed that polyester hydrolysis had a major impact on API release kinetics, while in PLA/PPAd blends with high PLA content, drug release was mainly controlled by diffusion.

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Surface Tension in Polymer Blends of Isotactic Poly(propylene) and Atactic Polystyrene

Macromolecular Materials and Engineering ◽

10.1002/1439-2054(20011201)286:12<744::aid-mame744>3.0.co;2-a ◽

2001 ◽

Vol 286 (12) ◽

pp. 744 ◽

Cited By ~ 11

Author(s):

Zofia Funke ◽

Christian Schwinger ◽

Rameshwar Adhikari ◽

Jörg Kressler

Keyword(s):

Surface Tension ◽

Polymer Blends ◽

Atactic Polystyrene ◽

Poly Propylene

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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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