Phase separation induced by crystallization in blends of polycaprolactone and polystyrene: an investigation by etching and electron microscopy

Shabana, H.M.; Olley, R. H.; Bassett, D. C.; Jungnickel, B.‐J.

doi:10.1016/s0032-3861(99)00713-2

Cited by 55 publications

(46 citation statements)

References 37 publications

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“…This phase separation will lead to a rapid crystallisation of the DBS phase; a similar process has been observed in blends of crystallisable polymers. [10] To explore the effects of dispersing small quantities of DBS in PCL in more detail, we have obtained X-ray scattering data on samples of PCL/DBS and PCL without the additive subjected to the same thermal profile and in some cases the same flow profile. Preformed discs were heated into the melt at 80 8C within the shear cell and held for 5 min.…”

Section: Resultsmentioning

confidence: 99%

Directed Crystallisation of Poly(ε‐caprolactone) using a Low‐Molar‐Mass Self‐Assembled Template

Wangsoub

Olley

Mitchell

2005

Macro Chemistry & Physics

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Summary: We show that small quantities of dibenzylidene sorbitol dispersed in poly(ε‐caprolactone) coupled with shear flow provide a self‐assembling nanoscale framework to yield high levels of crystal orientation. During modest shear flow of the melt, the additive forms highly extended nanofibrils which adopt a preferred alignment with respect to the flow field, and on cooling polymer crystallisation is directed by these fibrils. We use in situ time‐resolving SAXS and WAXS techniques to explore how this behaviour can be modified by the composition, the shear rate and strain as well as the temperature at which the shear flow is imposed. SAXS studies show that the 3% DBS completely dissolves in the PCL melt at temperatures ≥120 °C and that any shear flow imposed at temperatures above such values is ineffective in directing crystallisation.

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Section: Resultsmentioning

confidence: 99%

Directed Crystallisation of Poly(ε‐caprolactone) using a Low‐Molar‐Mass Self‐Assembled Template

Wangsoub

Olley

Mitchell

2005

Macro Chemistry & Physics

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“…The kinetics of that phase separation and of crystallization may compete. In particular -crystallization induced phase separation can be observed which starts at the locations of high NCC content; 60,63,69,83 -phase separation induced crystallization may arise; 73 -immediate competition between crystallization and binodal or spinodal phase separation can occur. 61,72,73 Crystalline/Crystalline Polymer Blends First reports on the crystallization kinetics and the morphology of crystalline/crystalline polymer blends with homogeneous melt stem from the late 1970s and early 1980s [Stein et The structural features found so far are summarized in Figure 1.…”

Section: Htc/ncc Systems: Crystallization Induced Composition Changesmentioning

confidence: 99%

Crystallization kinetical and morphological peculiarities in binary crystalline/crystalline polymer blends

Liu

Jungnickel

2007

J Polym Sci B Polym Phys

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A survey is presented on the crystallization kinetics and the morphology of miscible crystalline/crystalline polymer blends. There are only few corresponding systems. In them, however, a number of strange kinetic and structural phenomena can be observed: (i) spherulitic crystallization of the components side‐by‐side, (ii) “interpenetrating crystallization,” (iii) “interlocking spherulitic crystallization,” and (iv) “interfilling crystallization.” Cocrystallization is forbidden for crystallographic reasons. The blend partners grow instead in their own lamellar stacks, and mixed lamellar stacks are a seldom and questionable exception. They crystallize also usually stepwise and not simultaneously. Upon step crystallization, the crystallization of the second component is determined by its redistribution with crystallization of the former. Those composition inhomogeneities are an independent issue that arises also with the development of the morphology in crystalline/amorphous blends, and a corresponding survey is yielded, too. The blend poly (vinylidene fluoride)/poly‐β‐hydroxybutyrate is a convenient model system as it can show all of these morphological and kinetic features after suitable thermal treatment. Some of them are demonstrated in the present publication. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1917–1931, 2007

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“…[4,5] Blends between polystyrene and polycaprolactone have been investigated mainly as a tool for fundamental blend studies, and especially competition between liquid-liquid phase separation (demixing) and liquid-solid phase separation (crystallisation). [6][7][8][9][10][11] A wide variety of morphologies was obtained according to the phase separation and crystallisation conditions. Most of the reported studies are restricted to polystyrene oligomers, leading to blends showing a critical upper solution temperature.…”

Section: Introductionmentioning

confidence: 99%

Nanoscale Blends between Immiscible Polymers via Simultaneous Non‐Interfering Polymerisation

Zinck¹,

Brachais²,

Finot³

et al. 2005

Macro Chemistry & Physics

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Summary: An important topic in polymer science seeks to improve the performances of polymer blends using nanoscale phase segregation. Here, blends between polystyrene and polycaprolactone are realised by a chemical route. The non‐interfering character of the radical polymerisation of styrene and the lanthanide halide initiated ring‐opening polymerisation of caprolactone is assessed. The molecular weights range from 2 000 to 3 500 for polycaprolactone and up to 140 000 for polystyrene, with reasonable polydispersity indexes. From calorimetry measurements, it is shown that polystyrene and low molecular weight polycaprolactone are immiscible. The morphology of the blends between the two immiscible polymers studied by atomic force microscopy is consistent with nanometer‐scale phase segregation.AFM surface image of a nanoscale blend.magnified imageAFM surface image of a nanoscale blend.

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Phase separation induced by crystallization in blends of polycaprolactone and polystyrene: an investigation by etching and electron microscopy

Cited by 55 publications

References 37 publications

Directed Crystallisation of Poly(ε‐caprolactone) using a Low‐Molar‐Mass Self‐Assembled Template

Directed Crystallisation of Poly(ε‐caprolactone) using a Low‐Molar‐Mass Self‐Assembled Template

Crystallization kinetical and morphological peculiarities in binary crystalline/crystalline polymer blends

Nanoscale Blends between Immiscible Polymers via Simultaneous Non‐Interfering Polymerisation

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