TY - JOUR
T1 - Effect of chain end group on surface glass transition temperature of thin polymer film
AU - Jiang, Xiqun
AU - Yang, Chang Zheng
AU - Tanaka, Keiji
AU - Takahara, Atsushi
AU - Kajiyama, Tisato
N1 - Funding Information:
This work was partially supported by a Grant-in-Aid for COE Research from the Ministry of Education, Science, Sports, and Culture, Japan. X.J. is grateful for partial support from NSFC.
PY - 2001/4/2
Y1 - 2001/4/2
N2 - Surface glass transition behaviors of proton end capped poly(2-vinylpyridine) (P2VP-H) and perfluoroalkyl end capped poly(2-vinylpyridine) (P2VP-C2C8F) thin films were investigated based on temperature-dependent lateral force microscopic (TDLFM) measurement. It is found that the species of chain end groups have significant influence on the surface glass transition temperature of the thin polymer film. For both samples, it is revealed that the surface glass transition temperatures decrease significantly in comparison to the bulk ones, and the magnitude order of reduction in surface Tg for P2VP-C2C8F is larger than that for P2VP-H. The apparent activation energy of surface α-relaxation calculated from the Arrhenius plot is ca. 292 ± 40 and 212 ± 40 kJ/mol for P2VP-H and P2VP-C2C8F, respectively, and is much smaller than the bulk one. The depression of the surface Tg for thin polymer films is explained by the excess free volume induced by the enrichment of chain end groups at the surface.
AB - Surface glass transition behaviors of proton end capped poly(2-vinylpyridine) (P2VP-H) and perfluoroalkyl end capped poly(2-vinylpyridine) (P2VP-C2C8F) thin films were investigated based on temperature-dependent lateral force microscopic (TDLFM) measurement. It is found that the species of chain end groups have significant influence on the surface glass transition temperature of the thin polymer film. For both samples, it is revealed that the surface glass transition temperatures decrease significantly in comparison to the bulk ones, and the magnitude order of reduction in surface Tg for P2VP-C2C8F is larger than that for P2VP-H. The apparent activation energy of surface α-relaxation calculated from the Arrhenius plot is ca. 292 ± 40 and 212 ± 40 kJ/mol for P2VP-H and P2VP-C2C8F, respectively, and is much smaller than the bulk one. The depression of the surface Tg for thin polymer films is explained by the excess free volume induced by the enrichment of chain end groups at the surface.
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U2 - 10.1016/S0375-9601(01)00150-5
DO - 10.1016/S0375-9601(01)00150-5
M3 - Article
AN - SCOPUS:0035794882
SN - 0375-9601
VL - 281
SP - 363
EP - 367
JO - Physics Letters, Section A: General, Atomic and Solid State Physics
JF - Physics Letters, Section A: General, Atomic and Solid State Physics
IS - 5-6
ER -