Photon Factory Activity Report 2004 #22 Part B (2005)
Materials Science

10C/2003G281

Nano-scale sstructure of amphiphilic block copolymer / homopolymer blends
Sunyoung JUNG, Takeshi YAMADA, Hirohisa YOSHIDA*1
Department of Applied Chemistry, Graduate School of Engineering, Tokyo Metropolitan University,
Hachiouji, Tokyo 192-0397, Japan, 1 CREST (JST)Introduction
For di-block copolymers with fine controlled blocksequences,lamellar,hexagonal-packed
cylinder,bicontinuous cubic gyroid and body-centered cubicstructures are confirmed as equilibrium structures. Thesenano-scale ordered structures are formed mainly by theresults of repulsive interaction between copolymer
components. We have reported the nano-scale orderedstructure and phase transitions of amphiphilic di-block
copolymer consisted with hydrophilic and hydrophobic
sequenceshavingazobenzene
moieties(p(EO)mpMA(Az)n) [1-4]. The di-block copolymers
composed of block sequences including azobenzene
moieties, which acts as a mesogen of side chain typeliquid crystalline polymer, form the hexagonal-packed
cylinder phase as a nano-scale ordered structure, anddemonstrate several phase transitions including liquid
crystalline and isotropic transitions [1, 2].
Fromthepolymerizationdifficultyofp(EO)npMA(AZ)m with high degree of polymerization ofp(EO),
thenano-scaleorderedstructureofp(EO)npMA(AZ)m having higher p(EO) content had notinvestigated yet. In this study, the nano-scale orderedstructure and the mixing state of blends ofp(EO)114pMA(AZ)m and homo p(EO)114 polymer having
same degree of polymerization of p(EO) were discussed.

copolymer p(EO)114pMA(Az)40 and these blend systems
showed the SAXS peaks observed at scattering vector in
the relation of 1 : 3 : 4 : 7 , which indicated thatthe nano-scale order structure was a hexagonal packed
cylinder for p(EO)114pMA(Az)40 and blends with p(EO)40
in the φ p (EO ) range below 35 %. With increasing φ p (EO ) ,the high-order SAXS peaks (4 and 7 ) became

smaller, the SAXS profiles of the blends with φ p (EO )above 40 % has no high-order peaks corresponding
to 4 and 7 . The lattice distance of (100) plan forp(EO)114pMA(Az)40 and blends p(EO)114pMA(Az)40 /p(EO)114pMA(Az)40/p(EO)114,andp(EO)40,p(EO)114pMA(Az)40 / p(EO)454 were shown in Fig.1 as afunction of φ p (EO ) .

ExperimentalTheamphiphilic
di-blockcopolymer,p(EO)114pMA(Az)40 (Scheme 1) and poly(ethylene oxide)
homopolymer, p(EO)n (n = 40, 114 and 454) were usedthrough this study. The blends were prepared by solution
casting method from toluene solution, and were dried
under reduced pressure. The p(EO) content of blends,
φ p (EO ) , were shown as B40-n in wt %. Before SAXS
measurement, all samples containing p(EO)114pMA(Az)24
were annealed at 140 oC for 24 hrs in order to form theequilibrium nano-scale ordered structure.
The SAXS measurements were carried out at thebeam line 10C at Photon Factory, High Energy
Acceleration Organization, Tsukuba, Japan. The
wavelength of monochromatic X-ray was 0.1488 nm. The
distance between sample and detector (PSPC, Rigaku Co.
Ltd, 512 channels) was 860 mm, which covered 1.02 nm< s-1 = q/2π = λ/2sinθ < 60.8 nm.
Results
The nano-scale ordered structure for blend samples
through micro-phase separation was determined by smallangle X-ray scattering (SAXS). The SAXS profiles of128

Users' Report

Fig.1 Effect of blend content on the lattice lengthof (001) plan for p(EO)114pMA(Az)40 and theseblendsReferences[1] Y. Tian, K. Watanabe, X. Kong, J. Abe, and T. Iyoda,
Macromolecules, 35, 3739 (2002)[2] K. Watanabe, Y. Tian, H. Yoshida, S. Asaoka, and T. Iyoda,Trans. Materials Res. Soc. Jpn, 28, 553 (2003)[3] H. Yoshida, K. Watanabe, R. Watanabe, Y. Tian, S. Asaoka,and T. Iyoda, Polym. Prep. Jpn, 51, 2150 (2002)[4] H. Yoshida, K. Watanabe, R. Watanabe and T. Iyoda,, Trans.
Materials Res. Soc. Jpn, 29, 861 (2004)* yoshida-hirohisa@c.metro-u.ac.jp