Flow Instability of Poly(vinyl alcohol)/Dimethyl Sulfoxide Solution under Steady Shear

Title
Flow Instability of Poly(vinyl alcohol)/Dimethyl Sulfoxide Solution under Steady Shear
Author(s)
주상우도성열류창열[류창열]노석균이용록심재진김준호Yeong Soon Gal[Yeong Soon Gal]한성수류원석
Keywords
SOL-GEL TRANSITION; MOLECULAR-WEIGHT; RHEOLOGICAL PROPERTIES; VINYL PIVALATE; ALCOHOL); TEMPERATURE; POLYMERIZATION; POINT
Issue Date
201106
Publisher
ISMITHERS
Citation
POLYMERS & POLYMER COMPOSITES, v.19, no.6, pp.451 - 458
Abstract
The effects of solution temperature and molecular weight on the rheological responses of poly(vinyl alcohol) (PVA) semidilute solutions (13 g/dL - 19 g/dL) in dimethyl sulfoxide (DMSO) have been studied using PVA with two different number-average degrees of polymerization (P(n)): 1700 and 4000. For the rheological experiments using dynamic shear, the PVA solution with a P(n) of 1700 showed rather simple Newtonian fluid behaviour, whereas that with P(n) of 4000 exhibited non-Newtonian shear thinning behaviour. Steady shear rheology experiments suggested that the lower P(n) PVA solutions were Newtonian fluids, which is consistent with the dynamic shear rheology results. However, an abrupt decrease of shear viscosity at high shear rates was observed for the higher P(n) PVA solutions at lower temperatures, such as 30 degrees C and 50 degrees C. At higher temperatures of 70 degrees C and 90 degrees C, the higher molecular weight PVA solutions exhibited simple shear thinning behaviour without any further complications of flow instability. The fact that temperature plays a critical role in controlling the observed flow instability of the PVA solutions in DMSO strongly suggests that there exist enhanced inter-chain interactions by hydrogen bonding of PVA chains beyond the chain entanglements, particularly for the higher P(n) PVA semidilute solutions at low temperatures. Therefore, it is important to consider both chain entanglements and hydrogen bonding interactions in order to process PVA solutions without causing undesirable flow instability.
URI
http://hdl.handle.net/YU.REPOSITORY/25133
ISSN
0967-3911
Appears in Collections:
공과대학 > 기계공학부 > Articles
섬유패션학부 > 섬유패션학부 > Articles
총장실 > 총장실 > Articles
공과대학 > 화학공학부 > Articles
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE