Blends of bisphenol A polycarbonate (PC) and poly(methyl methacrylate) (PMMA) prepared by screw extrusion and solution casting have been investigated by differential scanning calorimetry and scanning electron microscopy. From the measured glass transition temperatures (Tg) and specific heat increments (ACp) at the Tg, the PMMA appears to dissolve more in the PC-rich phase than does the PC in the PMMA-rich phase. The blend appears to be near equilibrium under extrusion as well as solution-casting conditions so that the Flory-Huggins interaction parameter between PC and PMMA was calculated and found to be 0.039 ± 0.004 for extruded blends at 250 °C and 0.043 ± 0.004 for solution-cast blends at 25 °C. Scanning electron microscopy supports the conclusion that the compatibility increases more in the PMMA-rich compositions than in the PC-rich compositions of the PC/PMMA blends.

The effects of compatibilizers and hydrolysis on the tensile and impact strength, interfacial tension and morphology of the PP/PLA (80/20) blends were investigated. For the PP/PLA (80/20) blends before hydrolysis, the tensile strength of the blends reached a maximum when the polypropylene-g-maleic anhydride (PP-g-MAH) copolymer was added at 3 phr. For the PP/PLA (80/20) blends after hydrolysis, the tensile strength did not change appreciably with the PP-g-MAH content. For the blends with the styrene-ethylene-butylene-styrene-g-maleic anhydride (SEBS-g-MAH) before or after hydrolysis, the tensile strength of the blends decreased with increasing SEBSg-MAH content. The interfacial tension of the PP/PLA (80/20) blend was determined from the relaxation time using the Palierne and Choi-Schowalter models, and showed a minimum value at a PP-g-MAH content of 3 phr in each model. For the PP/PLA (80/20) blends with the SEBS-g-MAH before and after hydrolysis, the increase in impact strength was more significant for the blends after hydrolysis. This suggests that PLA becomes less brittle after hydrolysis. The impact strength suggests that the SEBS-g-MAH is an effective impact modifier to improve the impact strength of the PP/PLA (80/20) blends.

SynopsisBlends of bisphenol-A polycarbonate (PC) and polystyrene (PS) prepared by screw extrusion and solution casting have been investigated with weight fractions of PC in the blends varying from 0.95 to 0.05. From the measured glass transition temperatures ( 2 ' ' ) and specific heat increments (AC,) at the Tg, the polystyrene appears to dissolve more in the PC phase than does the PC in the PS phase. The blend appears to be near equilibrium under extrusion conditions so that the polymer-polymer interaction parameter of PC/PS blends was calculated and found to be 0.038 5 0.004 for extruded blends at 250OC. Scanning electron micrascopy supports the conclusion that the compatibility increases more in the regions of PS-rich compositions than in the regions of PC-rich compositions of the PC/PS blends.

SynopsisPhase behavior of blends of bisphenol A polycarbonate ( P C ) with polystyrene ( P S ) , poly (styrene-co-acrylonitrile) (SAN) , poly (acrylonitrile-butadiene-styrene) ( ABS) , poly ( methyl methacrylate) (PMMA), poly (ethylene terephthalate) ( P E T ) , and poly (butylene terephthalate) ( P B T ) has been investigated. Blends were prepared by screw extrusion and solution casting with weight fractions of PC in the blends varying from 0.90 to 0.10. From the phase diagram of the blends, it appears that PS, SAN, ABS, PMMA, PET, and PBT dissolve more in the PC-rich phase than does PC ih the PS-, SAN-, ABS-, PMMA-, PET-, and PBT-rich phases. Also, from the measured glass transition temperature ( T8) of the screw-extruded blends and the solution-cast blends, it appears that compatibility increases more in the PS-, SAN-, ABS-, PMMA, PET-, and PBT-rich compositions than in the PC-rich compositions. Composition-dependent values of the polymer-polymer interaction parameters (g12 ) of various blends were calculated and found to be from 0.034 to 0.053 for equal weights of each of the polymers with PC.( SAN ) , l4

Blends of bisphenol‐A polyarbonate (PC) and poly(ethylene terephthalate) (PET) has been investigated by differential scanning calorimetry and scanning electron microscopy. Blends were prepared by screw extrusion and solution casting with weight fractions of PC in the blends varying from 0.90 to 0.10. From the measured glass transition temperature (Tg) and apparent weight fractions of PC and PET dissolved in each phase, it appears that PET dissolves more in the PC‐rich phase than does the PC in the PET‐rich phase. The composition‐dependent values of the Flory–Huggins polymer–polymer–interaction parameter were determined and found to be from 0.054 to 0.037 for extruded blends at 275°C and from 0.058 to 0.040 for solution casting at 25°C. The interaction parameter decreases with increasing PET concentration. This result is consistent with the values of the Tgs, the microscopy study, and the measured extrudate swell ratios which show that compatibility increases more in the PET‐rich compositions than in the PC‐rich compositions. The PC–PET blends are not microscopically miscible for all the blend compositions.