A chain geometry prediction of polystyrene and polyarylate block copolymer by a kinetic simulation model

Ohishi, Hiroshi; Nishi, Toshio

doi:10.1002/(sici)1099-0518(20000115)38:2<299::aid-pola4>3.0.co;2-x

Cited by 11 publications

(13 citation statements)

References 17 publications

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“…A kinetic simulation model for the radical polymerization of HOOC‐PS‐COOH has been also realized by Ohishi and Nishi 53. They used a simplified scheme and simulation of Coner42 where PRT is not considered.…”

Section: Resultsmentioning

confidence: 99%

Kinetic Evaluation of Cooperative [Co(salen)] Catalysts in the Hydrolytic Kinetic Resolution of rac‐Epichlorohydrin

et al. 2010

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A wide variety of [Co(salen)] catalysts with different structures designed to enhance salen–salen cooperative interactions have been reported as catalysts for the hydrolytic kinetic resolution (HKR) of epoxides. However, the myriad catalysts have been evaluated under inconsistent experimental conditions, at different catalyst loadings, at different temperatures, with various epoxides and in several different laboratories, making rigorous comparisons between the catalysts impossible. To this end, 12 representative catalysts from our studies, as well as catalysts originally described by others, are reported in the HKR of epichlorohydrin under rigorously identical conditions. The comparison of the reactivity and selectivity of the different catalysts indicates that the soluble, oligomeric [Co(salen)] catalysts with cyclic frameworks impart the highest activity and enantioselectivity (>99 % ee, krel>99) in this representative reaction, requiring very short reaction times (<30 min), including the most active catalyst reported to date for the target reaction. In general, it is found that soluble polymer or oligomer‐supported catalysts are more active than insoluble supported catalysts under the conditions used. Among the insoluble catalysts, a polymer resin supported [Co(salen)] catalyst with excellent enantioselectivity (>99 % ee, krel>99) and medium reaction time (222 min), is the most active and selective of the class. The lessons demonstrated herein regarding design of active and selective catalysts offer useful insights into refining design strategies for other related cooperative catalytic reactions, suggesting emphases on catalyst flexibility and solubility under reaction conditions.

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Section: Resultsmentioning

confidence: 99%

Kinetic Evaluation of Cooperative [Co(salen)] Catalysts in the Hydrolytic Kinetic Resolution of rac‐Epichlorohydrin

et al. 2010

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“…1). 6–8 We also previously reported its high potential for optical applications6, 7, 9 and for a compatibilizer for an immiscible blend system of high‐impact polystyrene (HIPS) and polycarbonate (PC) 11, 12…”

Section: Introductionmentioning

confidence: 98%

“…We carried out research and development on polystyrene–polyarylate (PS–PAr) block copolymers 6–12. In our earlier publications, we proposed a novel synthetic procedure of PS–PAr block copolymer utilizing a telechelic PS (Fig.…”

Section: Introductionmentioning

confidence: 99%

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

Ohishi¹,

Ikehara²,

Nishi³

2001

J of Applied Polymer Sci

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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.

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“…We carried out research and development on polymer blends based mainly on polystyrene and polyarylate (PS–PAr) block copolymers 24–29. In our earlier publications, we proposed a novel synthetic procedure for a PS–PAr block copolymer (Fig.…”

Section: Introductionmentioning

confidence: 99%

“…In our earlier publications, we proposed a novel synthetic procedure for a PS–PAr block copolymer (Fig. 1)24–26 and reported its high potential for high‐precision optical applications 24, 25, 27…”

Section: Introductionmentioning

confidence: 99%

Phase morphologies and mechanical properties of high‐impact polystyrene (HIPS) and polycarbonate blends compatibilized with polystyrene and polyarylate block copolymer

Ohishi

Ikehara

Nishi

2001

J of Applied Polymer Sci

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Phase morphology and mechanical properties of blends of high-impact polystyrene (HIPS) and polycarbonate (PC) blends compatibilized with a polystyrene (PS) and polyarylate (PAr) (PS-PAr) block copolymer were investigated. Over a broad range of composition from 50/50 through 30/70, HIPS/PC blends formed cocontinuous structures induced by the flow during the extrusion or injection-molding processes. These cocontinuous phases had heterogeneity between the parallel and perpendicular directions to the flow. The micromorphology in the parallel direction to the flow consisted of stringlike phases, which were highly elongated along the flow. Their longitudinal size was long enough to be longer than 180 m, while their lateral size was shorter than 5 m, whereas that in the perpendicular direction to the flow showed a cocontinuous phase with regular spacing due to interconnection or blanching among the stringlike phases. The PS-PAr block copolymer was found to successfully compatibilize the HIPS/PC blends. The lateral size of the stringlike phases could be controlled both by the amount of the PS-PAr block copolymer added and by the shear rate during the extrusion or injection-molding process without changing their longitudinal size. The HIPS/PC blend compatibilized with 3 wt % of the PS-PAr block copolymer under an average shear rate of 675 s Ϫ1 showed a stringlike phase whose lateral size was reduced almost equal to the rubber particle size in HIPS. The tensile modulus and yield stress of the HIPS/PC blends could be explained by the addition rule of each component, while the elongation at break was almost equal to that of PC. These mechanical properties of the HIPS/PC blends can be explained by a parallel connection model independent of the HIPS and PC phases. On the other hand, the toughness factor of the HIPS/PC blends strongly depended on the lateral size of the stringlike phases and the rubber particle size in the HIPS. It was found that the size of the string phases and the rubber particle should be smaller than 1.0 m to attain a reasonable energy absorbency by blending HIPS and PC.

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A chain geometry prediction of polystyrene and polyarylate block copolymer by a kinetic simulation model

Cited by 11 publications

References 17 publications

Kinetic Evaluation of Cooperative [Co(salen)] Catalysts in the Hydrolytic Kinetic Resolution of rac‐Epichlorohydrin

Kinetic Evaluation of Cooperative [Co(salen)] Catalysts in the Hydrolytic Kinetic Resolution of rac‐Epichlorohydrin

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

Phase morphologies and mechanical properties of high‐impact polystyrene (HIPS) and polycarbonate blends compatibilized with polystyrene and polyarylate block copolymer

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