高分子常用的热分析仪器说明.ppt

* * * * * * * * * * * * * This is a fire retardant sample test with TGA-FTIR. Customer want to know that does any toxic compound might be produced after decomposition. After real time testing, we get the maximal absorption peak at 531 second, and it has a CN absorption peak at about 2200 wavelength . * This is the same sample,shows the TGA weight loss v.s. FTIR spectrum . Page * 黏彈機械性質 ex. 模數(Modulus), 黏度(Viscosity), 阻尼相(tan d) … 微小的相變化 ex. b,g- transition, Tg以DSC/TMA測量不易者 … 活化能(Activation Energy)計算 預測材料使用壽命 ex. Creep Recovery, Time-temp. superposition … 模擬製程中材料及環境變化 ex. Curing process, controlled humidity, Solvent Immersion … 什麼時候您需要 DMA … Page * 黏性 彈性 ?o time ?o time ?o time ? = 0? ? = 90? ?o ?o ?o time ?o ? k DMA即為利用Sine Wave震盪方式, 測量回應的分析儀 材料的黏彈性質… Page * Idealized DMA Scan E’/Pa Temperature /K Tm - melting (1) Rubbery Plateau (2) Ta or Tg Tb (6) (5) (4) (3) (2) (1) local bend side gradual large chain motions and groups main scale slippage stretch chain chain Tg (6) Rubbery plateau is related to Me between crosslinks or entanglements. For thermosets, no Tm occurs. Beta transitions are often related to the toughness. Tg is related to Molecular mass up to a limiting value. For purely crystalline materials, no Tg occurs. In semicrystalline polymers, a crystal-crystal slip, Ta* occurs. Tll in some amorphous polymers (5) (4) (3) Page * Frequency effects things too Transitions shift Behavior changes Frequency E’ ? More fluid More elastic Page * So frequency can act like temperature Frequency E’ Temperature E’ Page * DMA 連結... 材料結構特性 製程加工特性 成品特性 Molecular weight MW Distribution Chain Branching Cross linking Entanglements Phases Crystallinity Free Volume Localized motion Relaxation Mechanisms Stress Strain Temperature Heat History Frequency Pressure Heat set Material Behavior Dimensional Stability Impact properties Long term behavior Environmental resistance Temperature performance Adhesion Tack Peel Page * DMA 是如何運作的? Storage Mod