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Surface thermomechanical and glass transition temperature measurements of polymeric solids
Author(s) -
Kajiyama Tisato,
Tanaka Keiji,
Takahara Atsushi
Publication year - 1997
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.19971180187
Subject(s) - glass transition , polystyrene , materials science , copolymer , polymer , dispersity , natural rubber , polymer chemistry , methyl methacrylate , contact angle , composite material , chemical engineering , engineering
The surface molecular motion of polymeric solids was investigated on the basis of scanning force microscopic and temperature‐dependent X‐ray photoelectron spectroscopic measurements. The surface of the monodisperse polystyrene films was in a glass‐rubber transition state even at 293 K in the case of number‐average molecular weight less than ca. 30k. The surface glass transition temperature, Tgs for the symmetric poly(styrene‐ block ‐methyl methacrylate) diblock copolymer films were much lower than those for the bulk samples. A remarkable depression of Tg at the air‐polymer interface was explained by the surface localization of chain end groups.