![]() ![]() (1989) Small-Angle Neutron Scattering from Star-Branched Polymers in Dilute Solution. īoothroyd, A.T., Squires, G.L., Fetters, L.J., Bennie, A.R., Horton, J.C. (2001) Structure Factors Effects in Small-Angle Scattering from Block Copolymer Micelles and Star Polymers. Journal of Polymer Science B, 42, 3081-3094. (2004) Scattering Functions of Semidilute Solutions of Polymers in a Good Solvent. (1990) Molecular Structures and Solution Viscosities of Ethylene-Propylene Copolymers. (2000) Viscometric Properties of Viscosity Index Improvers in Lubricant Base Oil over a Temperature Range. (1978) Mechanism of Action of Viscosity Index Improvers. (1911) Eine Neue Bestimmung der Moleküldimensionen. Journal American Chemical Society, 64, 1557-1560. (1942) The Effect of Temperature and Solvent Type on the Intrinsic Viscosity of High Polymer Solutions. (1987) Transition of Linear Polymer Dimensions from Theta to Collapsed Regime. Macromolecular Rapid Communications, 29, 160-164. ![]() (2008) Probing the Contraction and Association of Polystyrene Chains in Semidilute Solution by Non-Radiative Energy Transfer. Tao, F., Wang, X., Che, B., Zhou, D., Chen, W., Xue, G., Zou, D. (1976) The Dimensions of Polystyrene near and below the Theta Temperature. (1995) Two-Stage Kinetics of Single-Chain Collapse. (1998) Comparison of Inter- and Intramolecular Correlations of Polystyrene in Poor and Theta Solvents via Small-Angle Neutron Scattering. Melnichenko, Y.B., Wignall, G.D., Hook, W.A.V., Szydlowski, J., Wilczura, H. In: Cebe, P., Ed., Scattering from Polymers, ACS Symposium Series, Washington, 317-327. (1999) SANS Studies of Polymers in Organic Solvents and Supercritical Fluids in the Poor, Theta and Good Solvent Domains. Melnichenko, Y.B., Kiran, E., Heath, K., Salaniwal, S., Cochran, H.D., Stamm, M., Hook, W.A.V. (1974) The Determination of Chain Statistical Parameters by Light Scattering Measurements. Journal of Chemical Physics, 78, 183-189. (1983) Temperature Dependence of Hydrodynamic Dimensions of Polystyrenes in Cyclohexane by Quasielastic Light Scattering. (1958) The Non-Newtonian Characteristics of Lubricating Oils. In: Lubricant Additives, CRC Press, Boca Raton, 315-337. (2009) Polymethacrylate Viscosity Modifiers and Pour Point Depressants. In: Lubricant Additives, CRC Press, Boca Raton, 283-314. (2009) Olefin Copolymer Viscosity Modifiers. The results will show that coil size expansion with temperature is not necessary to achieve significant elevation of viscosity index.ĪSTM, D2270: Standard Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 and 100☌. To address this issue, intrinsic viscosity measurements and Small-Angle Neutron Scattering (SANS) have been used to study the variation of polymer coil size with changing temperature and concentration in a selection of solvents. However, there is very little physical data supporting this generally accepted mechanism. VI improvement by VMs is widely attributed to the polymer coil size expanding with increasing temperature. The VI of both mineral and synthetic base oils can be improved by the addition of polymeric viscosity modifiers (VMs). Viscosity Index (VI) is one approach used widely in the lubricating field to assess the variation of viscosity with temperature. One of the requirements of engine lubricating oil is that it must have a low enough viscosity at low temperatures to assist in cold starting and a high enough viscosity at high temperatures to maintain its load-bearing characteristics.
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