Preparation and Characterization of Block Copolymers of Ordinary and Deuterated Styrenes

Matsushita, Yushu; Furuhashi, Hiroshi; Choshi, Haruhisa; Noda, Ichiro; Nagasawa, Mitsuru; Fujimoto, Teruo; Han, Charles C.

doi:10.1295/polymj.14.489

Cited by 19 publications

(6 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Polystyrene-d 8 (PSD) used for the blend was synthesized in the laboratory using standard techniques of anionic polymerization of styrene-d 8 in benzene with sec-butyllithium as an initiator. 48 Gel permeation chromatography (GPC) performed using THF as solvent was used to determine the weight-average molecular weights (M w ) of the PSD and PVME and their polydispersities (M w /M n ), where M n is the number-average molecular weight. The weight-average molecular weights and the molecular weight distributions thus found were 38300 and 1.03 for PSD and 23700 and 4.26 for PVME (see Table 1).…”

Section: Methodsmentioning

confidence: 99%

“…Samples of PVME in water (50 wt % of solute) obtained from Aldrich Chemical Co. were vacuum-dried at room temperature for 48 h before being used for the preparation of deuterated polystyrene/poly(vinyl methyl ether) (PSD/PVME) blends. Polystyrene- d 8 (PSD) used for the blend was synthesized in the laboratory using standard techniques of anionic polymerization of styrene- d 8 in benzene with sec -butyllithium as an initiator . Gel permeation chromatography (GPC) performed using THF as solvent was used to determine the weight-average molecular weights ( M w ) of the PSD and PVME and their polydispersities ( M w / M n ), where M n is the number-average molecular weight.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Miscibility Determination of a Lower Critical Solution Temperature Polymer Blend by Rheology

Sharma

Clarke

2004

J. Phys. Chem. B

View full text Add to dashboard Cite

Rheology on a miscible blend of deuterated polystyrene (PSD) and poly(vinyl methyl ether) (PVME) is reported in the temperature range of T g (glass-transition temperature) + 45 K to T g + 155 K, extending from homogeneous to the two-phase region of the blend's phase behavior. Data obtained from rheology, performed in different modes of applied shear, has been used to determine the miscibility range of this particular blend system. Phase separation temperature and the region of miscibility are determined from the dynamic temperature sweep experiment carried out in the parallel plate geometry. While the binodal temperature is marked by the first change in the slope of the storage modulus and the peak, in the tan δ curve, miscible and phase-separated regions are identified as the off-peak zones. Shift factors obtained from the time-temperature superposition (tTS) exhibit Williams-Landel-Ferry (WLF) behavior in the homogeneous region. Thermorheological complexity observed through the failure of tTS and deviation from temperature independence of Han plots in the terminal region near the phase boundary suggests the onset of phase separation in the rheologically identified metastable region. In addition to the qualitative analysis of the temperature-dependent viscosity data (in the linear viscoelastic regime) where the observed departure in viscosity-temperature relationship is interpreted as signature of spinodal decomposition, quantitative analysis of the shear rheological data based on mean-field theory has been used to determine the spinodal temperature of the PSD/PVME blend system. The estimated correlation length, near the critical region, exhibits divergence caused by enhanced concentration fluctuations. However, Onuki's prediction of viscosity enhancement at high shear rates near the critical region, a characteristic associated with phase separation in two-component systems, could not be observed for the PSD/PVME blend.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Miscibility Determination of a Lower Critical Solution Temperature Polymer Blend by Rheology

Sharma

Clarke

2004

J. Phys. Chem. B

View full text Add to dashboard Cite

show abstract

“…This monomer contained deuterated monobromobenzene and some other substances as impurities which could not be removed completely by the ordinary purification process used for the synthesis of protonated block polymers. 33 These impurities react slowly with polystyryl anion to terminate further propagation, resulting in a broad distribution of molecular weight and composition. Therefore we employed the thorough purification technique proposed by Matsushita et al33 The deuterated styrene monomer was further purified by a mixture of (triphenylmethyl)lithium and lithium bromide just before the polymerization.34 Thus the impurities were essentially completely removed from the monomer.…”

Section: Introductionmentioning

confidence: 99%

SANS and SAXS studies on molecular conformation of a block polymer in microdomain space

Hasegawa¹,

Hashimoto²,

Kawai³

et al. 1985

Macromolecules

View full text Add to dashboard Cite

% Protonated Figure 10. Plot of the relative intensity of the 1015-1020-cm'1 Raman band of 2% solutions of PVI in 0.88 M aqueous NaCl vs. extent of protonation. and 915 cm'1 shift to 1511,1096, and 945 cm'1, respectively, upon metal incorporation.B. The proton-bridged complex causing viscosity minima and double breaks in the potentiometric titration curves for PVI was characterized by FTIR and Raman spectra.1. FTIR of dried films shows marker bands in the regions 2400-2600 and 900-950 cm'1 which appear to be associated with H bonding upon partial protonation. The band shifts in the 900-950-cm'1 region for protonated and Ni-complexed PVI suggest similar intrachain bridging or cross-linking in the two systems. 2. A conformational change of the backbone upon protonation is supported by the Raman spectra and is attributed to the formation of the H-bridged complexes.Acknowledgment. We are grateful to Professor J. Koenig for discussion of some of the spectral assignments and to C. S. Baker and W. Brattlie for technical assistance.Registry No. PVI (homopolymer), 25232-42-2. References and Notes(1) Tan,

show abstract

“…[6][7][8][9] In the present work, we determined the radii of gyration of deuterated sections of polystyrenes by small-angle neutron scattering, using block copolymers of ordinary and deuterated polystyrenes having narrow molecular weight distributions both in each block and in the whole molecule. 10 The samples were prepared carefully, as previously described, in view of the fact that scattering from block copolymers is very sensitive to heterogeneities in both molecular weight and composition.…”

Section: Introductionmentioning

confidence: 99%

Expansion factor of a part of a polymer chain in a good solvent measured by small-angle neutron scattering

Matsushita¹,

Noda²,

Nagasawa³

et al. 1984

Macromolecules

Self Cite

View full text Add to dashboard Cite

show abstract

Preparation and Characterization of Block Copolymers of Ordinary and Deuterated Styrenes

Cited by 19 publications

References 8 publications

Miscibility Determination of a Lower Critical Solution Temperature Polymer Blend by Rheology

Miscibility Determination of a Lower Critical Solution Temperature Polymer Blend by Rheology

SANS and SAXS studies on molecular conformation of a block polymer in microdomain space

Expansion factor of a part of a polymer chain in a good solvent measured by small-angle neutron scattering

Contact Info

Product

Resources

About