材料物理实用.pptx

材料物理实用第1页/共33页3 QuestionsWhat is polymer solution?Why to study polymer solution?HOW to study polymer solution?第2页/共33页What is polymer solution?polymer + solventTraditionalpolymer + polymerCover第3页/共33页Why to study polymer solution?Study Best method on investigation of a single polymerApplictionsBondDopeFilaturePlastic enhancedBlend第4页/共33页HOW to study polymer solution?Polymer solution processHow to select a solventSolution state：Interaction solution and separateSolution thermodynamics第5页/共33页Gibbs 方程 G=H-TS1873~1878Josiah Willard Gibbs (1839-1903)? 状态Insluable，Phase Seperate第6页/共33页Key points for polymer dissolvingLinear polymersSwelling to solutionMelting to solutionCrystalline polymersOnly swellingCross-linked polymers第7页/共33页Solvent selectionSimilar dissolve mutually theory Non- PolarityNon- PolarityPolarityPolaritySolubility parameter ? = ?1/2 =第8页/共33页(2) Similar solubility parameterCED –Cohesive energy densityGibbs free energy 自由能Enthalpy 焓Entropy 熵Condition of solutionDuring solution process第9页/共33页Therefore ?HM is the key Polar polymer to polar solvent，?HM 0, Self-solution-process.(b) In general，?HM 0, Solution is depended on the comparison of ?HM and T?SM. ?HM T?SM, Soluble 。?HM need be more little 。第10页/共33页Hildebrand equationHildebrand J., Scott R.L., Solubility of Nonelectrolytes, Reinhold Publishing Corporation, New York, Chapter 7 (1949)?1, ?2 – Volume fraction of Solvent and polymer, respectively .?1, ?2 – Solubility parameter fraction of Solvent and polymer, respectively .VM – Volume after blending Polymer is insolubleIn general,第11页/共33页Hildebrand function is good for non- or weak polar polymerFor polar polymer, Hansen公式:Blend solvent： ? = ?1/2 =第12页/共33页How to get ? ?第13页/共33页(a) Swelling method：Cross-linked polymer is dissolved in different solvents. The ? of the solvent with the largest swelling volume is the ? of polymer.第14页/共33页(b) Viscoelasticity methodPolymer is dissolved in different solvents. The ? of the solvent with the larges