Kang Maoqing

The Mechanical Properties of polyurethane Elastomer Reinforced and Toughened By CaSO4-Whisker

CaSO4 whisker reinforcing and toughening mechanisms for polyurethane elastomer were studied. The effects of dispersity of CaSO4 whisker and interfacial bonding state on reinforcement and toughness were discussed. The microanalyses showed that CaSO4 whisker reinforcing mechanism for polyurethane elastomer mainly was load transferring and its toughening mechanism involved crack deflection and whisker pullout. The results indicated that composites with 5%–10% CaSO4 whisker exhibited the best mechanical properties. Good bonding interface was formed between whisker and matrix after the surface of CaSO4 whisker was treated by silane coupling agent. The fairly improved strength and toughness are attributed to the better interfacial bonding state.

Mechanical properties and morphology of the clay/waterborne polyurethane nanocomposite

Stable clay/waterborne polyurethane nanocompostie dispersions were synthesized by sulfonated poly (butylene adipate) diol, 4,4-diphenylmethane diisocyanate, dimethyl propionic acid, 1,4-butanediol, triethyl amine and clay-water dispersion through a route named prepolymer acetone mixing progress. The reinforced mechanical properties and thermal resistance of films casting from it were examined by dynamic mechanical analyses (DMA), thermogravimetric analyses (TGA) and tensile tests. Furthermore, the morphology of these nanocompostie films and dispersions were observed by transmission electron microscopy (TEM), scanning electron microscopy (SEM), wide-angle X-ray diffraction analyses (WXRD). The experimental results reveal that the clay could be predominantly dispersed in the pristine polymer forming nanocomposties, and evidently enhanced the tensile properties and modulus of it. Additionally, the best-reinforced effect could occur when the clay content was near 1 wt%.