in Thin Films of Poly(1,6-hexamethylene adipate)/ Poly(vinyl methyl ether) Blend

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Single Crystalline Morphology and Lamellar Assembly in Thin Films of Poly(1,6-hexamethylene adipate)/

Poly(vinyl methyl ether) Blend

HPI-FAPS International Conference on Innovation in Polymer Science and Technology 2013

Ya-Ting Hsieh, Eamor M. Woo*

Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan

O

(CH₂)₆ O

C

(CH₂)₄ C

O O ⁿ

n CH₂

CH₂

O

CH₃

PVME M_w= 96,700 g/mol, T_g= -22.5 ^oC

PHA M_w= 11,000 g/mol, T_g= -65 ^oC, T_m= 55.3 ^oC.

- 2006, GestÍ S. et al.

Orthorhombic unit cell/ zigzag planar conformation (all-trans) (WAXD & ED pattern result)

(a = 1.008 nm, b = 1.464 nm, c = 1.683 nm), 8 chains/cell.

Ref. GestÍ S. et al., Biomacromolecules, 7, 799 (2006); Woo E. M. et al. Polym. J., 42, 398 (2010)

- 2010, Woo E. M. et al.

Miscible phase behavior of water-soluble PVME blends with PHA.

Interaction parameter (c₁₂) = -0.21 (DSC analysis)

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Method

Sample preparation: solvent blending (PHA/PVME = 80/20)>>

spin coating/drop casting on glass slides (well dry) >>

melt-crystallization

Sample observation: polarized optical microscopy (POM) / atomic force microscopy (AFM) / electron diffraction (ED)

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(220) (220) -

a*

(040) b*

ED

(220)

(220) (400)

a* -

(040) b*

ED POM

30 mm

AFM POM

10 mm

AFM

nucleus

Results

In ultrathin film state (~200 nm)

T_c = 38 ^oC T_c = 46 ^oC

flat-on flat-on

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Results

In thin film state (2-3 mm)

POM

2 mm

60 mm 6 mm

Height image Phase image

3 mm

150 mm 25 mm

Height image Phase image

T_c = 38 ^oC

T_c = 46 ^oC

flat-on

edge-on

In lower T_c sample, the AFM phase image shows that both edge-on and flat-on lamellae are the main species in negative-birefringence spherulites with random arrangement. However, in higher T_c sample, only flat-on lamellae exist in its positive- birefringence spherulites.

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Results

In thin film state (2-3 mm)

T_c = 46 ^oC-1 min-38 ^oC-0.2 min cycled

POM

55 mm

radial direction

Phase image

150 mm

900 nm

radial direction

Height image

Main concept of this study:

The alternating ring bands can be packed with mechanisms different from the conventionally thought continuous spiral of a continuous lamella.

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