Observation of a reversible thermotropic order-order transition in a diblock copolymer
- Princeton Univ., NJ (United States). Dept. of Physics
- Princeton Univ., NJ (United States). Dept. of Chemical Engineering
- Exxon Research and Engineering Co., Annandale, NJ (United States). Corporate Research Science Lab.
- Massachusetts Inst. of Technology, Cambridge, MA (United States). Dept. of Materials Science and Engineering
The authors report the observation of a reversible thermotropic transition between the lamellar and cylindrical morphologies in a polystyrene-poly(ethene-co-butene) diblock copolymer. The nature of the intermediate structures which form as the transition progresses has been examined using two-dimensional small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Results show that the transformation from the lamellar to the cylindrical morphology proceeds in two steps. Initially, fluctuations along the interface joining the components of the copolymer grow in amplitude until the lamella transforms into a sheet of eventually spaced cylinders; cylinders which form in adjacent lamellae are usually in poor register with one another. This intermediate structure subsequently anneals into the hexagonal packing of cylinders characteristic of the cylindrical morphology. The reverse transition from cylinders to lamellae proceeds without producing any intermediate signature detectable by SAXS.
- DOE Contract Number:
- FG02-87ER60522
- OSTI ID:
- 5045104
- Journal Information:
- Macromolecules; (United States), Vol. 27:2; ISSN 0024-9297
- Country of Publication:
- United States
- Language:
- English
Similar Records
Nanocomposites Based on Coil-Comb Diblock Copolymers
Morphologies of poly(cyclohexadiene) diblock copolymers
Related Subjects
COPOLYMERS
PHASE TRANSFORMATIONS
EXPERIMENTAL DATA
MORPHOLOGICAL CHANGES
POLYOLEFINS
POLYSTYRENE
DATA
INFORMATION
MATERIALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PLASTICS
POLYMERS
POLYVINYLS
SYNTHETIC MATERIALS
360602* - Other Materials- Structure & Phase Studies