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Dielectric investigation of the molecular dynamics in blends: polymers with similar molecular architecture (TMPC/PC blend)
Author(s) -
Mansour Ashraf A.,
Madbouly Samy A.
Publication year - 1995
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.1995.210360306
Subject(s) - polycarbonate , glass transition , materials science , dielectric , relaxation (psychology) , polymer blend , polymer , atmospheric temperature range , polymer chemistry , composite material , chemical engineering , thermodynamics , copolymer , psychology , social psychology , physics , optoelectronics , engineering
Broad band dielectric spectroscopy was used in the investigation of the molecular dynamics and compatibility of tetramethyl polycarbonate/polycarbonate (TMPC/PC) blends. Frequency scan measurements in the range 10 −2 −10 −5 Hz were carried out in the temperature range 50–220°C for several blends with different compositions, namely, 0, 12.5, 25, 50, 75, 87.5 and 100 wt% of TMPC. The results obtained show that these two polymers are ideally compatible over the entire composition range. The blends reveal only one common glass process. The dielectric relaxation strength and the common glass transition temperature, T g , were found to vary linearly with composition. Moreover, it was found, surprisingly, that blending has no effect on the distribution of relaxation times of the common glass process of the blends. Furthermore, neither the kinetics (relaxation frequency at a certain temperature) nor the distribution of relaxation times of the local process were influenced by blending. It is concluded that the polymeric chains of the different components are not miscible on a segmental level although the blend exhibits only one glass transition temperature.