Broadband dielectric study on binary blends of bisphenol-A and tetramethylbisphenol-A polycarbonate

• Published in: Macromolecules Vol. 26; no. 12; pp. 3075 - 3080
• Main Authors: Katana, G, Kremer, F, Fischer, E. W, Plaetschke, R
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-06-1993
• Subjects: Applied sciences; Electrical, magnetic and optical properties; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Properties and characterization; Bisphenol A; Alpha relaxation; Property composition relationship; Experimental study; Beta relaxation; Polycarbonate; Activation energy; Mixture; Dielectric relaxation
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma00064a013

Broadband dielectric spectroscopy (10 exp --1 -10 exp 7 Hz) and differential scanning calorimetry (DSC) have been used to study the alpha - and beta -relaxations in blends of bisphenol-A polycarbonate (BPA-PC) and tetramethylbisphenol-A polycarbonate (TMBPA-PC) in the temperature range from 93-553K. All blends show one broadened alpha -relaxation as compared with the homopolymers. At temperatures below T sub g the beta -relaxations corresponding to both homopolymers are observed in the blends. The beta -relaxation strength obeys dilution laws with no indication of a critical TMBPA-PC concentration above which the beta -relaxation in BPA-PC is totally suppressed.