Gradual change of conformational disorder

Conference · Sat Dec 31 00:00:00 EST 1994

OSTI ID:230378

Wunderlich, B

The basic step of crystallization of linear macromolecules is conformational ordering. If the ordering is completed during crystallization, the entropy of fusion is a measure of the gain of conformational disorder on melting. In this lecture the possibility is discussed that in some cases conformational order changes below the glass or disordering transitions (T{sub g} and T{sub d}, respectively). Changes in conformational order below T{sub g} were observed for some flexible macromolecules without side-chains, like polyethylene. Changes below T{sub d} are found among main-chain liquid-crystalline polymers, conformationally disordered (condis) crystals, and related small-molecule model-compounds.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 230378
• Report Number(s): CONF-9410455-1; ON: DE96009624; TRN: 96:003026
• Resource Relation: Conference: International symposium on unsolved problems on polymer crystalization, Tokyo (Japan), 24-25 Oct 1994; Other Information: PBD: 1994
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
POLYETHYLENES
PHASE TRANSFORMATIONS
CRYSTALLIZATION
ENTROPY
GLASS
MELTING
POLYMERS
SPECIFIC HEAT
TRANSITION TEMPERATURE