Introduction to polymer science Polymer composites and blends

Introduction to polymer science Polymer composites and blends 高分子复合材料与共混四川大学化学学院

Question • Why are composite materials necessary ? • How/what are composites made of ? • Where are composites usefully applied? Fiberglass Mud and straw homes • Composites are engineered materials made from two or more materials with significantly different physical or chemical properties which remain separate and distinct on morphology within the finished structure.

Polymer composites and blends Polymer Composites

Fiber reinforced composites 玻璃纤维碳纤维 critical length Long fiber: Length > critical length Short fiber: Length < critical length 芳纶纤维

Fiber reinforced composites Continuous fiber Discrete fiber Woven fabric Using for laminated composites

Laminar Composites

Nanocomposites

Polymer nanocomposites

Modification of CNT oxidative acid diol OH COOH Polymer

Application of polymer composites

Polymer composites and blends Polymer Blends

Characterization of polymer blends (AFM) HDPE + 30 wt% Nylon 6 (SEM) EPR + 30 wt% PP (TEM)

Characterization of polymer blends Tg-2 Tg-1 Immiscible Tg-2 Tg-1 Partial miscible Tg miscible • Fox equation: • Gordon-Taylor equation: •

Droplet Coalescence 不相容高分子体系在高于熔点的条件下会出现液滴聚集现象，从而导致明显相分离的粗糙形貌 Scanning Electron Microscope photographs of the structural coarsening of a blend (holes have been produced by “etching” (dissolving) the dispersed phase using a solvent)

Compatibilizer and Etching Solvent for disperse phase LDPE/PS blend without a compatibilizer LDPE/PS blend with a compatibilizer Etching Solvent for the matrix