Elongational viscosity for miscible and immiscible polymer blends. I. PMMA and AS with similar elongational viscosity

Abstract

ABSTRACT:The effects of miscibility and blend ratio on uniaxial elongational viscosity of polymer blends were studied by preparing miscible and immiscible samples at the same composition by using poly(methyl methacrylate) (PMMA) and poly(acrylonitrileco-styrene) (AS). Miscible polymer blend samples for the elongational viscosity measurement were prepared by using three steps: solvent blends, cast film, and hot press. A phase diagram of blend samples was made by visual observation of cloudiness. Immiscible blend samples were prepared by maintaining the prepared miscible samples at 200°C, which is higher than cloud points using a LCST (lower critical solution temperature) phase diagram. The phase structure of immiscible blends was observed by an optical microscope. The elongational viscosity of all samples was measured at 145°C, which is lower than the cloud-point temperature at all blend ratios. The elongational viscosity of PMMA and AS was similar to each other. The strain-hardening property of miscible blends in the elongational viscosity was only slightly influenced by the blend ratio, and this was also the case with immiscible blends. The strain-hardening property was only slightly influenced, whether it was miscible or immiscible at each blend ratio. Polydispersity in molecular weight for blend samples was not changed by GPC (gel permeation chromatography) analysis. Almost no change in the polydispersity of the molecular weight for blends and the similarity of elongational viscosity between PMMA and AS resulted in little influence of the blend ratio and miscibility on the strainhardening property.

The Influence of Heat Treatment on Uniaxial Elongational Flow Behavior of PS/SBS Blends

“…This preparation method follows that in a previous work. 6) For PS and PS/SBS blends without annealing, the sample was heated under 10 MPa at 180 °C and cooled gradually below T g . In cases of PS and PS/SBS blends with annealing, the samples were heated under 10 MPa at high temperatures (220, 240, and 260 °C) for 60 min and cooled rapidly.…”

Extension rheology of liquid-crystalline solution/layered silicate hybrids

“…The common explanation of strain-hardening is associated with increase of intermolecular interactions at stretching. It is typical for long-chain branched [56] and polar polymers [57]. It was also established that strain-hardening is enhanced by the presence of a small amount of polymer fractions with ultra-high molecular weight [58].…”

Study on Uniaxial Elongational Viscosity and Vacuum Molding Processability of the PP/PE Blends

“…による測定装置の考案以 来，伸長粘度に関する研究が大きく進展した． これまでの高分子の一軸伸長粘度の研究により，歪み硬化 性を発現させる因子として，長鎖分岐構造 2,3) ，分子量分布 4,5) ， 高分子量成分の存在 4,6) ，微量の超高分子量成分の存在 [7][8][9] が指 摘されている．また，伸長粘度と成形加工性の関係について も多く報告されている． 7,10) しかし，これまでの伸長粘度に関 する研究の多くはPE，PSを扱っていた．また，ブレンド系に 関してもPEを中心とした相溶系が多く扱われてきた．非相溶 系についてはPS，PMMA，AS等の非オレフィン系樹脂に関す る報告 [11][12][13] が多い． PPの伸長粘度に関する研究例 9,14) は少なく，…”