In the present research, the relationship between blend miscibility and constituent polymer structure was established. This work examines a series of blends of polyesters (PE's) and polycarbonates (PC's) having systematic variations in aliphatic and aromatic structural group content to establish how miscibility and phase behavior depend on polymer structure. The blends were prepared by solution blending and precipitating, while the polymer blend miscibility and phase behavior were characterized through differential scanning calorimetry (DSC). The glass transition temperatures (Tg) of the individual polymers and blends were measured. The polyesters and polycarbonates explored in this research were 4MC-PC (Tg = 135.2°C), BPA-TMC-PC 9371 (Tg = 213.4°C), Lexan 145 BPA-PC (Tg = 152.7°C), Teijin BPA-PC (Tg = 149.5°C), N-PC (Tg = 235.5°C), TCD-PC (Tg = 267.1°C), T(60)Az-N (Tg = 147.2°C), and T(80)Az-N (Tg = 74.8°C). Generally, it was found that polycarbonate-polycarbonate blends were miscible, while polycarbonate-polyester and polyester-polyester blends were partially miscible at most. Of the 50:50 blends studied, the miscible blends were Lexan 145 BPA-PC and BPA-TMC-PC 9371, N-PC and BPA-TMC-PC 9371, TCD-PC and BPA-TMC-PC 9371, N-PC and Lexan 145 BPA-PC, and TCD-PC and N-PC. The partially miscible blends were T(80)Az-N blended with BPA-TMC-PC 9371, Lexan 145 BPA-PC, Teijin-PC, N-PC, TCD-PC, and T(60)Az-N. Other partially miscible blends included Teijin-PC and TCD-PC, and T(60)Az-N blended with BPA-TMC-PC 9371, N-PC, and TCD-PC. The blend that showed to be immiscible was T(60)Az-N and Lexan 145 BPA-PC. The results showed that blends made up of two polycarbonates with similarities in aromatic and aliphatic group content brought about a miscible blend. For the PC-PE and PE-PE blends, those with more similar structural content were more miscible than those with less similar structural content.
Library of Congress Subject Headings
Polymers--Structure; Solution (Chemistry)
Department, Program, or Center
School of Chemistry and Materials Science (COS)
Hendrick, Theresa, "Structure-miscibility relationships in weakly interacting polymer blends" (2012). Thesis. Rochester Institute of Technology. Accessed from
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