Phase morphology of polystyrene–polyarylate block copolymer/polycarbonate blends and their application to disk substrates

Abstract

Polystyrene-polyarylate (PS-PAr) block copolymer was applied as a moldability modifier of polycarbonate (PC). From the 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) extraction results, PS-PAr block copolymer was demonstrated to copolymerize with PC via an in situ reaction between the PAr chain and PC. As a result of the chemical bonding between PS and PC chains, the PS dispersed domain in the PS-PAr block copolymer/PC blend could be reduced, on average, to a size smaller than the visible light wavelength. In particular, by adjusting PAr composition to 30 wt % in the fed PS-PAr block copolymer during the melt-mixing process, the PS domain size was completely reduced to be smaller than the visible light wavelength. As a result the blend substrate could satisfy the transparency required for the optical disk substrate with higher memory density: homogeneity under polarizing light, clarity on the reflective plate, and transparency at 400 nm. The melt viscosity could be lowered to the equal viscosity level of PC at about 30°C higher temperature by blending PC 15 wt % with the PS-PAr block copolymer. The lowered melt viscosity could reduce the retardation in the optical disk substrate, which was equivalent to that of the PC substrate processed at 30°C higher. In addition, the PS-PAr block copolymer/PC blend could attain the exact groove transcription at 20°C lower mold temperature than that of PC as a result of the lowered elastic modulus caused by the PS-rich phase. These features of the PS-PAr block copolymer/PC blend indicated a potential to offer an improved process window for the substrate molding. Because of its excellent transparency and a potential for processing flexibility, the PS-PAr block copolymer/PC blend would be a promising material for optical disk substrates with higher memory density.

Mechanistic aspects of ester–carbonate exchange in polycarbonate/cycloaliphatic polyester with model reactions

“…In recent years, considerable interest has arisen in the reactive blending of polymers containing active functional groups in the polymer chains during the melt-mixing processes. [2][3][4][5][6][7][8][9][10][11] The materials produced through reactive blending are more compatible, homogeneous, and less sensi-tive to long-term phase separation. 12 Polyesters and polycarbonates are mostly used for engineering thermoplastics because of their excellent mechanical and thermal properties.…”

Characterization and Processing Behavior of Heated Aluminum-Polycarbonate Composite Build Plates for the FDM Additive Manufacturing Process

“…Also, the rings constrain the rotation of the chains around the carbon-carbon bonds, impacting its rigidity. PC and HIPS appear to form local weak bonds easily without high heat or a long processing time [75]. For these reasons, it can be reasonably predicted that a HIPS and PC plate will adhere, but the bond will be fairly weak.…”

Preparation and characterization of polysiloxane–polyacrylates composite lattices by two seeded emulsion polymerization and their film properties

“…According to the optical principle, when the disperse phase domain size was smaller than one half of wavelength of light, the light could round the disperse phase. 35,36 As listed in Table I, the transparency decreased as the polysiloxane content increased but when the seed latex content was 10 wt % the transparency was still acceptable. It is mainly because that the dispersed polysiloxane phase domain size was expected to be much smaller than the visible light wavelength (400-800 nm).…”