WebFigure 9.2 also shows the differing solubility of poly (methyl methacrylate) in the three solvents at a temperature of 303 K. In a good solvent (toluene), the slope or Aj is large, but … WebThe quality of solvent depends also on temperature. For a flexible polymer, low temperature may correspond to poor quality and high temperature makes the same solvent good. At a particular temperature called theta (θ) temperature, the solvent behaves as if an ideal chain. Excluded volume interaction
Dilute-Solution Properties of Polystyrene Polymacromonomer …
WebEffect of solvent on chain dimensions: Good solvent - chain expansion Poor solvent - chain contraction Theta solvent - chain contraction exactly compensates for excluded volume effect 〈〉= 〈〉 = rro 22 α 1 A 2 = 0 for theta solvent WebFeb 15, 2024 · The solvent for the polymer at the θ temperature is called theta (or θ) solvent. A solvent is called good when the temperature T > θ, thus the steric repulsion prevails over the solvent-mediated attraction (excluded volume), and then the coil swells, being bigger than that in a θ solvent. tshwane university application
Chemistry C3102-2006: Polymers Section Dr. Edie Sevick, …
WebSolution For a good solvent, interactions between polymer segments and solvent molecules are energetically favorable, and will cause polymer coils to expand. For a poor solvent, polymer-polymer self-interactions are preferred, and the polymer coils …. Athermal-solvent Good-solvent 315 (3/5 Theta-solvent R 13/5 Poor-solvent 11/3 Non-solvent ST ... WebUne fibre optique est un fil dont l’âme [1], très fine, en verre ou en plastique, a la propriété de conduire la lumière et sert pour la fibroscopie, l'éclairage ou la transmission de données numériques. Elle offre un débit d'information nettement supérieur à celui des câbles coaxiaux et peut servir de support à un réseau « large bande » par lequel transitent aussi … WebPhase diagrams for polystyrene solutions in poor solvents and theta-solvents have been determined as functions of concentration, molecular weight and polydispersity, pressure, temperature, and H/D isotope substitution on both solvent and polymer, sometimes over broad ranges of these variables. tshwane tvet north college