• Macromolecular Research
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• v.13 no.6
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• pp.506-513
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• 2005

We review the recent SAXS activity on the 1.5-GeV electron storage ring at the National Synchrotron Radiation Research Center (NSRRC). Typical measurements featuring in grazing incident SAXS for soft materials are illustrated. Complex measurements using simultaneous SAXS/DSC and SAXSIWAXS for the correlations between the crystallization and mesoscale ordering in a polymer blend and a polypeptide-block-polypseudorotaxane diblock copolymer are presented. We also introduce a dedicated SAXS beamline which is planned at NSRRC.

• Macromolecular Research
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• v.14 no.1
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• pp.45-51
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• 2006

We conducted simultaneous, small-angle, X-ray scattering/differential scanning calorimetry (SAXS/DSC) and simultaneous, wide-angle, X-ray scattering (WAXS)/DSC measurements for a polymer blend of poly($\varepsilon$-caprolactone)/poly(ethylene glycol)(PCL/PEG). The time-dependent SAXS/DSC and WAXS/DSC results, measured while the system was quenched below the melting temperature of PCL from a melting state, revealed the competitive behavior between liquid-liquid phase separation and crystallization in the polymer blend. The time-dependent structural evolution extracted from the SAXS/WAXS/DSC results can be characterized by the following four stages in the PCL crystallization process: the induction (I), nucleation (II), growth (III), and late (IV) stages. The influence of the liquid-liquid phase separation on the crystallization of PCL was also observed by phase-contrast microscope and polarized microscope with 1/4$\lambda$ compensator.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.823-824
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• 2010

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.507-508
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• 2009

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.417-419
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• 2001

폴리(트리메틸렌 테레프탈레이트)(PTT)와 폴리(트리메틸렌 나프탈레이트)(PTN)는 모두 방향족 폴리에스테르계 고분자들이지만 같은 계열의 다른 고분자에 비해 연구가 많이 진행되어 있지 않다 특히 PTT가 포함된 블렌드계의 경우 최근에 들어서야 방향족 다른 폴리에스테르계 고분자와의 블렌딩에 관한 몇가지 보고가 있을 뿐이다[1-3]. (중략)

• Journal of Powder Materials
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• v.17 no.3
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• pp.209-215
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• 2010

Mesoporous alumina particles were prepared by spray pyrolysis using cetyltrimethyl-ammonium bromide (CTAB) as a structure directing agent and the effect of Al precursor types on the texture properties was studied using $N_2$ adsorption isotherms, small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The surface area and the microstructure of alumina particles were significantly influenced by the Al precursor type. The largest BET surface area was obtained when Al chloride was used, whereas alumina particles prepared from Al acetate had the largest pore volume. According to small-angle X-ray scattering (SAXS) analysis, the alumina powders prepared using nitrate and acetate precursors had a clear single SAXS peak around $2{\theta}=1.0{\sim}1.5^{\circ}$, indicating that regular mesopores with sponge-like structure were produced. On the basis of TEM, SAXS, and $N_2$ isotherm results, the chloride precursor was most profitable to obtain the largest surface area ($265\;m^2/g$), whereas, the nitrate precursor is useful for the preparation of non-hollow mesoporous alumina with regular pore size, maintaining high surface area (${\sim}233\;m^2/g$).

• Bulletin of the Korean Chemical Society
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• v.24 no.10
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• pp.1485-1489
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• 2003

The gelation for di-(2-ethylhexyl) phthalate (DEHP)-plasticized poly(vinyl chloride) was studied by measuring time-resolved small-angle X-ray scattering (SAXS) and a flow of the solutions in test tube. It was found that for the gelation there were three regimes. At Regime I, the solution rapidly changed to a gel, and the SAXS intensity showed a peak and the peak intensity increased, keeping the peak angle constant. Applying the SAXS intensity to the kinetic analysis of the liquid-liquid phase separation, it was revealed that the spinodal decomposition proceeded to develop a periodic length of 29.9 nanometer in size, a hydrogen-bonding-type association in polymer rich phase followed, and then it induced fast gelation rate. At Regime II, the gelation slowly occurred and the SAXS intensity was not observed, suggesting that a homogeneous gel network was formed by a hydrogen-bonding. At regime III, the solution was a homogeneous sol.

• Macromolecular Research
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• v.10 no.6
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• pp.304-310
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• 2002

In a recent study by the same authors using a DMTA (Dynamic Mechanical Thermal Analyzer), it was found that the 4-aminobenzoic arid (ABA) molecules acted as either a neutralizing agent, or a plasticizer, or a filler, depending on the order of mixing of poly(styrene-co-styrenesulfonic acid) (PSSA), ABA, and NaOH. Subsequent to that study, we here pursued the same topic, i.e., the effect of the addition of CsOH (instead of NaOH) and ABA on the morphology of PSSA, but this time, by using a small-angle X-ray scattering (SAXS) technique. In line with the previous results, the present study with the SAXS technique verified that the order of mixing has a significant effect on the morphology of ionomers. In addition, with the SAXS data and the density values of the ionomers, we attempted to calculate both the number of sulfonate ionic groups per multiplet and the size of the multiplet of the ionomer.

• Polymer(Korea)
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• v.27 no.6
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• pp.521-527
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• 2003

It was found that polypropylene shows rearrangement of crystal structure during the melting process. For the analysis of recrystallization behavior, the change of dynamic mechanical property, crystallinity, and crystal structure were studied by DSC, FT-IR, SAXS, and DMA. Melt-recrystallization-remelting behavior of iPP was clearly observed when iPP was cooled down kom the melt more rapidly. Elastic modulus of iPP increased during the recrystallization process but crystallinity of iPP shows constant value. Furthermore, the full width of half mean of SAXS pattern decreased about 30%, and intra-lamella ordering of iPP increased during the melt process but is was not found for sPP.

• Macromolecular Research
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• v.11 no.3
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• pp.152-156
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• 2003

We investigated epitaxial relations of phase transitions between the lamellar (L), hexagonally perforated layers (HPL), and gyroid (G) morphologies in styrene-isoprene diblock copolymer (PSI) and polyisoprene (PI)/PSI blend using rheology and small angle X-ray scattering (SAXS) techniques. In HPLlongrightarrowG transitions, six spot patterns of G phase were observed in two-dimensitional SAXS pattern. On the other hand, in direct L-longrightarrowG transition without appearance of HPL phase, the polydomain patterns of G phase were observed. From present study, it was understood that direct LlongrightarrowG transition of blend may be suppressed by high-energy barrier of transition and mismatches in domain orientation between epitaxially related lattice planes.