Coalescence during annealing of quiescent immiscible polymer blends

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Bojan Dimzoski ◽  
Ivan Fortelný ◽  
Miroslav Šlouf ◽  
Martina Nevoralová ◽  
Danuše Michálková ◽  
...  
Keyword(s):  
Polymer Blends ◽  
Complex Viscosity ◽  
Dispersed Phase ◽  
Approximate Theory ◽  
Immiscible Polymer Blends ◽  
Low Frequencies ◽  
Droplet Shape ◽  
Immiscible Polymer ◽  
The Matrix ◽  
Spherical Droplets

AbstractCoalescence during annealing of quiescent immiscible polymer blends, containing polypropylene (PP) matrix and different amount of ethylene-propylene copolymer (EPR) as dispersed phase, was studied. Comparison of experimental results with available coalescence theories revealed that changes in the phase structure after 20 min annealing can be precisely estimated using the approximate theory of coalescence induced by van der Waals forces and considering drainage of the matrix film between spherical droplets. All results evidenced growth of the EPR droplet size with the annealing time and temperature; increase in the content of dispersed phase contributed to higher growth rate of the dispersed phase, more pronounced at the coalescence origin. Anisometry of the EPR droplets and droplet shape relaxation were perceived, both interfering the course of coalescence. Enhanced elasticity of examined blends at low frequencies and positive deviation of the complex viscosity from the linear mixing rules was observed.

Fiber Reinforced Multiphase Polymer Composites by In situ Fiber Alignment

2007 ◽  
Vol 1054 ◽  
Author(s):  
Wantinee Viratyaporn ◽  
Nancy Twu ◽  
Richard Lehman
Keyword(s):  
Polymer Blends ◽  
Glass Fibers ◽  
Model System ◽  
Immiscible Polymer Blends ◽  
Immiscible Polymer ◽  
Novel Approach ◽  
Micron Size ◽  
The Matrix ◽  
Alignment Mechanism

ABSTRACTA novel approach has been explored for the efficient dispersion and uniaxial alignment of fibers in dual phase polymer matrices based on the streaming flow that occurs when two immiscible polymer blends are melt processed under high shear conditions. Such conditions improve the alignment and distribution of fibers in the matrix, a feature of particular importance when fine nanofibers are used. This self-alignment mechanism seeks to produce optimum properties from relatively small volume fractions of fiber. Recent efforts have focused on a model system containing micron-size glass fibers in immiscible polymer blends. This paper presents selected mechanical properties measured for the model system and the flow/orientation paradigm that produces the observed morphologies.

Morphology evolution during cooling of quiescent immiscible polymer blends: matrix crystallization effect on the dispersed phase coalescence

2012 ◽  
Vol 70 (1) ◽  
pp. 263-275 ◽  
Author(s):  
Bojan Dimzoski ◽  
Ivan Fortelný ◽  
Miroslav Šlouf ◽  
Antonín Sikora ◽  
Danuše Michálková
Keyword(s):  
Polymer Blends ◽  
Dispersed Phase ◽  
Morphology Evolution ◽  
Immiscible Polymer Blends ◽  
Immiscible Polymer ◽  
Crystallization Effect

Dispersed Phase Deformation Modeling of Immiscible Polymer Blends in Injection Molding

2015 ◽  
Vol 34 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Yi Zhang ◽  
Fen Liu ◽  
Zhigao Huang ◽  
Xiaolin Xie ◽  
Bin Shan ◽  
...  
Keyword(s):  
Injection Molding ◽  
Polymer Blends ◽  
Dispersed Phase ◽  
Immiscible Polymer Blends ◽  
Phase Deformation ◽  
Immiscible Polymer

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

2017 ◽  
Vol 34 (7) ◽  
pp. 2311-2329 ◽  
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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