Secondary crystallization of isotactic polystyrene
نویسندگان
چکیده
منابع مشابه
Extensional-flow-induced crystallization of isotactic polypropylene
A filament stretching extensional rheometer with a custom-built oven was used to investigate the effect of uniaxial flow on the crystallization of polypropylene. Prior to stretching, samples were heated to a temperature well above the melt temperature to erase their thermal and mechanical histories and the Janeschitz-Kriegl protocol was applied. The samples were stretched at extension rates in ...
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Dispersions of isotactic polypropylene (PP) particles in polystyrene (PS) were produced by interfacially driven breakup of nanolayers in multilayered systems that were fabricated by means of layer-multiplying coextrusion. The droplet size was controlled by the individual PP layer thickness ranging from 12 to 200 nm. In addition, PP was melt blended with PS to produce PP droplets larger than tho...
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The crystal growth of isotactic polystyrene (it-PS) is investigated in very thin, 11 nm thick films. The it-PS crystals grown in the thin films show quite different morphology from that in the bulk. With decreasing crystallization temperature, the branching morphology in a diffusion field appears: dendrite and compact seaweed. The branching morphology is formed through a morphological instabili...
متن کاملPhase-field modeling on morphological landscape of isotactic polystyrene single crystals.
Spatio-temporal growth of isotactic polystyrene single crystals during isothermal crystallization has been investigated theoretically based on the phase field model by solving temporal evolution of a nonconserved phase order parameter coupled with a heat conduction equation. In the description of the total free energy, an asymmetric double-well local free energy density has been adopted to repr...
متن کاملOne-pot synthesis of isotactic-capped syndiotactic polystyrene with a bimetallic homogeneous catalytic system
INTRODUCTION Polystyrene can be obtained in atactic (aPS), isotactic (iPS) or syndiotactic (sPS) form by a variety of catalytic systems1,2 and initiators. For instance, it is known that (pentamethylcyclopentadienyl)titanium derivatives activated by methylaluminoxane (MAO) afford a highly sPS, with %m (defined as meso diads content, calculated by 13C-nuclear magnetic resonance (NMR)) below the i...
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ژورنال
عنوان ژورنال: Journal of Polymer Science: Polymer Physics Edition
سال: 1974
ISSN: 0098-1273,1542-9385
DOI: 10.1002/pol.1974.180120805