Anomalous viscosity decrease of polycarbonate by addition of polystyrene

Sako, Takumi; Date, Jitsuhiro; Hagi, Misaki; Hiraoka, Tatsuhiro; Matsuoka, Shinji; Yamaguchi, Masayuki

doi:10.1016/j.polymer.2019.03.015

Cited by 22 publications

(21 citation statements)

References 27 publications

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“…This is reasonable because PS is known to be immiscible with PC. [17][18][19][20] In contrast, the blend with PS1k was found to be miscible, owing to the large contribution of the mixing entropy. The molecular weight of PS necessary for it to be miscible with PC can be estimated from the Flory-Huggins interaction parameter χ. Kim and Burns calculated the χ value between PC and PS to be 0.038 ± 0.004 at 250 C. 29 This value of the interaction parameter suggests that PS of molecular weight approximately 10,000 is miscible with PC at this blend ratio (PC/PS = 95/5), which corresponds well with results in the present study (miscible with PS1k and immiscible with PS53k).…”

Section: Resultsmentioning

confidence: 95%

“…Moreover, the spiral flow length at injection molding was greatly enhanced by the addition of only 5% of PS (148 mm for pure PC and 208 mm for PC/PS [95/5]). [17] Although this is a novel result to the best of our knowledge, the mechanism of the viscosity drop was not clarified.…”

Section: Introductionmentioning

confidence: 88%

“…In this study, therefore, we investigated the effect of the molecular weight of PS on the rheological properties and morphology of PC/PS blends. Although conventional PC and PS are known to be immiscible, [17][18][19][20] the PS sample with a low molecular weight used in this study is miscible with PC. Furthermore, it should be noted that PS samples showing phase separation from PC can decrease the shear viscosity greatly, especially at high shear rates.…”

Section: Introductionmentioning

confidence: 99%

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Effect of morphology on shear viscosity for binary blends of polycarbonate and polystyrene

Tanaka

Sako

Hiraoka

et al. 2020

J of Applied Polymer Sci

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The structure and rheological properties of binary blends of polycarbonate (PC) and polystyrene (PS) were investigated using various PS samples with different molecular weights, namely PS1k (Mw = 1,000), PS53k (Mw = 53,000), and PS240k (Mw = 240,000). The blends with PS53k and PS240k show phase‐separated structures, whereas the blend with PS1k is miscible. The shear viscosity decreases greatly on addition of PS53k and PS240k, especially at high shear rates, which would be a great advantage at processing operations. Because the nonlinear response occurs in the small strain region for multilayered films of PC and PS240k, the origin of the significant viscosity drop for the phase‐separated system is interfacial slippage at the phase boundary.

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Section: Resultsmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of morphology on shear viscosity for binary blends of polycarbonate and polystyrene

Tanaka

Sako

Hiraoka

et al. 2020

J of Applied Polymer Sci

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“…Furthermore, adding polystyrene (PS) with a low molecular weight was recently found to greatly decrease the shear stress of bisphenol‐A polycarbonate (PC). [ 33,34 ] For PC blends with PS, the decrease in shear viscosity was significant at high shear rate, that is, at high shear stress. This is different from the system with a plasticizer, and is an attractive method for increasing the flowability when injection molding.…”

Section: Introductionmentioning

confidence: 99%

“…In fact, the spiral flow length was reported to be greatly enhanced by adding a small amount of PS with low viscosity. [ 34 ] The viscosity drop was attributed to interfacial slippage between PC as a continuous phase and dispersed PS droplets. In this system, the PS droplets were highly deformed because of the large viscosity difference.…”

Section: Introductionmentioning

confidence: 99%

Viscosity decrease by interfacial slippage between immiscible polymers

Moonprasith

Nasri

Saari

et al. 2021

Polymer Engineering & Sci

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The rheological behavior under pressure‐driven shear flow was studied using binary blends with a sea‐island structure. The addition of a low‐viscosity dispersion having a high interfacial tension with the continuous phase greatly reduces the shear viscosity, for example, the addition of atactic polystyrene (PS) with a low viscosity to isotactic polypropylene (PP) and the addition of PP with a low viscosity to PS. The interfacial slippage occurs because of the poor adhesive strength with the enlarged interfacial area and is responsible for the viscosity decrease. When the dispersion has a similar viscosity to the continuous phase, the viscosity decrease is barely detected. This is because the deformation of dispersed droplets is restricted, which creates a small interfacial area. The interfacial tension between the continuous and dispersed phases plays a crucial role on the shear viscosity. In the case of PP, the addition of linear low‐density polyethylene with a relatively low interfacial tension to PP has almost no impact on the shear viscosity. This is despite the polyethylene having a low viscosity.

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Preparation of graded materials for miscible polycarbonate/poly(methyl methacrylate) blends by segregation under shear flow

Moonprasith

Tatsumichi

Nakamura

et al. 2022

J of Applied Polymer Sci

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Exposure to shear flow produced by a pressure‐driven capillary rheometer provides a concentration gradient without phase separation in miscible polymer blends of bisphenol‐A polycarbonate containing low‐molecular‐weight poly(methyl methacrylate) (PMMA). The strand surface extruded from the rheometer contains a large amount of PMMA. However, the strand is transparent because there is no light scattering due to phase separation. The segregation behavior, that is, enrichment of the PMMA content at the strand surface, is enhanced when the molecular weight of PMMA is low. Furthermore, the segregation is also enhanced at high temperatures and at high shear rates. By contrast, the die length barely affects the degree of segregation. The segregation phenomenon should be noted because it may facilitate the modification of the surface properties of various products.

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Anomalous viscosity decrease of polycarbonate by addition of polystyrene

Cited by 22 publications

References 27 publications

Effect of morphology on shear viscosity for binary blends of polycarbonate and polystyrene

Effect of morphology on shear viscosity for binary blends of polycarbonate and polystyrene

Viscosity decrease by interfacial slippage between immiscible polymers

Preparation of graded materials for miscible polycarbonate/poly(methyl methacrylate) blends by segregation under shear flow

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