Small-angle scattering investigations of poly(.epsilon.-caprolactone)/polycarbonate blends. 1. Small-angle neutron and x-ray scattering study of crystalline blend morphology

Cheung, Y. W.; Stein, Richard S.; Wígnall, G. D.; Yang, Hong-Mei

doi:10.1021/ma00072a012

Cited by 59 publications

(39 citation statements)

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“…From the peak position (Q M ), using Bragg's equation, a repeat distance d of about 28 Å was determined. These results are in fairly good agreement with literature data where a cluster size of 30 Å, composed of crystalline PC in a PCL-PC blend, was detected [23]. These clusters are correlated over a length of about 8 Å.…”

Section: Resultssupporting

confidence: 93%

“…It follows that it has to be ascribed to some structure induced in the polymer by the presence of the zirconia. The peak shape is similar to that observed by SAXS on crystalline PC [23], and which was ascribed to a lamellar structure. This finding suggests that the zirconia induced a local crystallization in the polymer.…”

Section: Resultssupporting

confidence: 80%

“…3B. Since the lowangle region of the pattern is dominated by a single peak, the presence of a cubic arrangement was excluded and, in agreement with literature [23], it was considered that the backbones of the polymer could arrange to form lamellae. On this basis, the model proposed by Nallet et al [24] was considered.…”

Section: Resultsmentioning

confidence: 77%

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Influence of the modification, induced by zirconia nanoparticles, on the structure and properties of polycarbonate

Motaung

Saladino

Luyt

et al. 2013

European Polymer Journal

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a b s t r a c tMelt compounding was used to prepare polycarbonate (PC)-zirconia nanocomposites with different amounts of zirconia. The effect of the zirconia loading, in the range of 1-5 wt.%, on the structure, mechanical properties and thermal degradation kinetics was investigated. The zirconia nanoparticle aggregates were well dispersed in the PC matrix and induced the appearance of a local lamellar order in the polycarbonate as inferred by SAXS findings. This order could be a consequence of the intermolecular interactions between zirconia and the polymer, in particular with the quaternary carbon bonded to the methyl groups and the methyl carbon as inferred from the NMR results. The presence of zirconia caused a decrease in the storage and loss moduli below the glass transition temperature. However, the highest amount of zirconia increased the modulus. The presence of zirconia in PC slightly increased the thermal stability, except for the highest zirconia content which showed a decrease. The activation energies of thermal degradation for the nanocomposites were significantly lower than that for pure PC at all degrees of conversion.

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Section: Resultssupporting

confidence: 93%

Section: Resultssupporting

confidence: 80%

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Influence of the modification, induced by zirconia nanoparticles, on the structure and properties of polycarbonate

Motaung

Saladino

Luyt

et al. 2013

European Polymer Journal

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“…Their curves are similar and both display a single endotherm at 60°C, which is clearly related to the melting point of PCL crystals. Because of the agreement of DSC curves of PCL and PCL/SAN blend, the a-and /3-forms can not be found in PCL/SAN blends, as is different from that in ref 8, where the DSC thermograms change when bright and dark spherulites co-exist. The W AXD patterns of PCL and PCL/SAN blends are displayed in Figure 4.…”

Section: Resultscontrasting

confidence: 73%

Novel Morphology in Ring-Banded Spherulites from Single-Phase Mixtures of Poly(ε-caprolactone) with Poly(styrene-co-acrylonitrile)

Wang

Jiang

et al. 1998

Polym J

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ABSTRACT:Novel morphology of ring-banded spherulites in the surface of poly(c-caprolactone)/poly(styrene-coacrylonitrile) (PCL/SAN) blends was discovered and studied by SEM and TEM. The ring-banded spherulites separate into those exhibiting a very dark contrast, of relatively regular bundles of lamellae and others appearing with a much brighter intensity, of a coarse and irregular aggregates of lamellae. The origin of the novel morphology is not due to different crystalline structures as in the case of isotactic polypropylene because only one crystal structure exists in PCL/SAN blends. The formation may reflect whether spherulites in PCL/SAN blends are nucleated at the bottom surface or at the top (free) surface.KEY WORDS Poly(E-caprolactone) / Poly(styrene-co-acrylonitrile) / Ring-Banded Spherulite / Morphology/ Polymers undergoing phase transformation show a wide variety of microstructures. The most common growth is termed "spherulitic." This form consists of radial arrays of lamellar crystals. Poly(s-caprolactone) (PCL) is miscible on a molecular level with poly(styreneca-acrylonitrile) (SAN) when copolymer contains from 8 to 28 wt¾ acrylonitrile. 1 When below the melting temperature (Tm) of PCL, PCL lamellae grow (crystallization), and between them, a homogeneous mixture of amorphous PCL and SAN should remain. The crystallization behavior of PCL is strongly influenced when amorphous SAN is present. This leads to ring-banded spherulites. 2 -5 However, to our knowledge, it is not enough, up to now, to investigate the morphology of ring-banded spherulites formed in PCL/SAN blends or the mixtures of PCL with other polymers by electron microscope. 2 -12 This paper studies novel spherulitic morphology on the surface of ring-banded spherulites generated in PCL/SAN blends. A possible formation mechanism of two types of ring-banded spherulites is discussed. EXPERIMENT ALPCL was purchased from Polysciences Inc. (U.S.A.). M w and Mn determined by gel permeation chromatography (GPC) are 22000 and 11300, respectively. The melting temperature of PCL is about 60°C from differential scanning calorometry (DSC) measurement. SAN with 25 wt¾ acrylonitrile (AN) content was supplied by Polysciences Inc. The Mw and Mn are 197000 and 106000 by GPC, respectively. Tg of SAN is about 105°C measured by DSC. Samples of PCL and PCL/SAN (90/10) blends were prepared by mixing in CH 2 Cl 2 . A dilute solution (5% wt/wt) was stirred continuously for 24 h at 25°C. The thin films were cast on a clean cover glass 1 To whom correspondence should be addressed. 206and held in a vacuum oven at 40°C for three days. The isothermal crystallization of PCL and PCL/SAN blends was performed on two home-made optical microscope hot stages, in which temperature was controlled within ± 0.1 °C. The films with a free surface upwards were first melted on one hot stage at 80°C for 5 h, then rapidly transported to another hot stage controlled at crystallization temperature (Tc) of 35°C and maintained for 24h.After crystallization, the films without surface treatm...

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“…In crystalline/crystalline system, since the constituents are able to crystallize and always possessed multiple structures as well as complicated crystallization process, the blend can form multi-scale and multi-morphology structures in the process from the liquid state (melt or solution) to the solid state providing a possibility to regulate their structure or morphology and to further modify the performances of the materials by adjusting the crystallization conditions. [1][2][3][4][5][6][7][8][9][10] The investigation of crystalline/crystalline blends has attracted much attention due to the great importance in both scientific and industrial fields.…”

Section: Introductionmentioning

confidence: 99%

Effect of blend composition on crystallization behavior of polyoxymethylene/poly(ethylene oxide) crystalline/crystalline blends

et al. 2011

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The influence of blend composition on crystallization behavior of a typical crystalline/crystalline blend, polyoxymethylene (POM)/poly(ethylene oxide) (PEO), during slow non-isothermal crystallization was investigated by polarized light microscope (PLM) connected with a THMS600 hot-stage, scanning electron microscope (SEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The experimental results indicated that with increasing PEO content in the blend, the crystallization temperature of POM of the blends reduced and the multiple crystalline morphologies or structures including two kinds of interfibrillar or interlamellar structures were produced. The melting point of each component decreased with raising the content of the other constituent due to the inclusion and entanglement between POM and PEO molecules. The shoulder melting peak of POM appeared in DSC heating traces of the PEOrich blend because the stronger inclusion and entanglement induced the imperfect crystallization of POM.

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Small-angle scattering investigations of poly(.epsilon.-caprolactone)/polycarbonate blends. 1. Small-angle neutron and x-ray scattering study of crystalline blend morphology

Cited by 59 publications

References 2 publications

Influence of the modification, induced by zirconia nanoparticles, on the structure and properties of polycarbonate

Influence of the modification, induced by zirconia nanoparticles, on the structure and properties of polycarbonate

Novel Morphology in Ring-Banded Spherulites from Single-Phase Mixtures of Poly(ε-caprolactone) with Poly(styrene-co-acrylonitrile)

Effect of blend composition on crystallization behavior of polyoxymethylene/poly(ethylene oxide) crystalline/crystalline blends

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