Solvent-Induced Crystallization and Interaction Parameter of the Blends of Bisphenol A Polycarbonate and Poly(phenyl methacrylate)

Abstract

ABSTRACT:Blends of bisphenol A polycarbonate (PC) and poly(phenyl methacrylate) (PPMA) were crystallized by tetrahydrofuran (THF) solvent to investigate the phenomena of solvent-induced crystallization. The optimum conditions for solvent induced crystallization in PC have been determined. Interaction parameter has been calculated based on the melting point depression method to estimate the extent of miscibility. A negative interaction parameter (z 12 = -0.21) obtained from the melting point depression method suggests that there is some attractive interaction between the blend components.KEY WORDS Blend / Solvent Induced Crystallization / Interaction Parameter / Polycarbonate (PC) has been widely used both as a blend partner and by itself because it has outstanding engineering properties. Furthermore, due to its remarkable transparency, PC has been recognized as a suitable plastic for optical storage disc. 1 -4 The criteria of such optical materials 4 require low birefringence, low hygroscopicity, high transmission, dimensional stability, processability, and good mechanical properties. These stringent requirements can be fulfilled by specially designed polycarbonates. 2 However, PC shows a large positive birefringence, 5 which might cause optical distortion, owing to the presence of aromatic groups in the main chain. This positive birefringence can be eliminated substantially by blending with a polymer which has negative birefringence and can form a single phase with the constituent polymer. Poly(phenyl methacrylate) (PPMA) may be chosen as the blend partner of PC to form a miscible birefringence-free blend. For this reason, the birefringence-free composition of the PC/PPMA blend may be determined. The copolymers of PPMA and their blends often been reported to be used as optical lenses 6 -16 and optical disk recording materials 1 7 because of the high refractive index (1.5706) and high transparency of PPMA. But PPMA is very brittle and has low dimensional and thermal stability. 18 On the other hand, PC shows tough and ductile properties, good processability, thermal stability, and good electrical properties, but its poor scratch resistance and thermal stresscracking with its large birefringence are disadvantages. lt can be expected, therefore, that the drawbacks of each pure component can be overcome by blending the two components. By controlling the compositions of the blends, the improvement of physical properties may be achieved.We have demonstrated that the blends of the PC/ PPMA are completely miscible 19 and the birefringence and tensile properties of the blends were excellent. It is therefore of paramount importance to identify the origin of miscibility and to estimate the extent of miscibility by determining z12 interaction parameter. It has been known that solvent-induced crystallization can occur in PC. In this paper, the phenomena of solvent-induced 970 crystallization and the melting behavior of PC in the blends have been investigated. Subsequently, z12 interaction parameter was calculated based on ...

Prediction of Thermal Behavior of Polycarbonate/Cerium Oxide Composite Films

“…1 compares the calorimetric behaviors during the first heating cycles of dry‐cast films of pure PC and nanocomposites at different ceria concentrations. The glass transition temperature ( T g ) of the pure PC film (132 °C) was significantly lower than that of pristine PC pellets (145 °C), likely due to some solvent traces able to act as a plasticizer even at concentration as low as 0.5 % 27. Ceria caused the T g of the polymer matrix to decrease down to about 80 °C, supposedly also favoring solvent‐induced PC crystallization.…”

“…(T g ) of the pure PC film (132°C) was significantly lower than that of pristine PC pellets (145°C), likely due to some solvent traces able to act as a plasticizer even at concentration as low as 0.5 % [27]. Ceria caused the T g of the polymer matrix to decrease down to about 80°C, supposedly also favoring solvent-induced PC crystallization.…”

Solvent-induced crystallization and phase-transition phenomena in syndiotactic polystyrene and its relatives

“…Solvent-induced crystallization and phase transition behavior of polymers have been attracting much attention in both the academic research and the industrial production. Many polymers have been found to exhibit the solvent-induced crystallization phenomenon, including polyethylene terephthalate (PET) (Desai and Wilkes, 1974;Durning et al, 1986;Ouyang et al, 2002;Ouyang et al, 2004), polybutylene terephthalate (PBT) (Waywood and Durning, 1987), polycarbonate (Sheldon and Blakey, 1962;Park and Hong, 1997), nylon (Liu et al, 1995), poly(ether ether ketone) (PEEK) (Cornélis et al, 1996) and so on. In some cases, the spatial orientations of the…”

Directed Hierarchical Patterning of Polycarbonate Bisphenol A Glass Surface along Predictable Sites

“…Among the promising solvents with suitable PC interactivity is acetone. Acetone-induced crystallization was studied extensively in the recent decade [10][11][12]; however, the fast dynamic of acetone crystallization results in the development of hierarchical spherules with high aspect ratio on the surface which reduce the glass transmittance dramatically and hence reduce their applicability in photovoltaic panels.…”