Preparation And Application Of PU-based Temperature Sensitive Composites

Poly(N- isopropyl acrylamide(PNIPAM) is a kind of typical thermo-responsive polymer materials.Its lower critical solution temperature(LCST) is about 33 ?.But it's application scope was limited by its poor membranous and adhesion, thus we use PNIPAM and PU as basis material to prepare composite material, which can overcome the shortcomings of PNIPAM. In addition, cotton cloth as a natural macromolecular material, has many excellent properties, are widely used in textile industry.In this work, PNIPAM/PU blend composite was prepared by the means of physical blending. The structure and performance of composite material were respectively characterized by FTIR, DSC, and TG and so on. Results shew that the composite material was a kind of thermo-responsive polymer materials, and its LCST can be changed by adjusting the content of PNIPAM. But the compatibility of blend composite was poor.Semi-IPNs were synthesized by PNIPAMPAN and PU with the strategy of in situ polymerization. Its compatibility and thermal stability were better than blend composite.Cotton was respectively processed by blend composite and Semi-IPN. Its surface morphology, thermosensitivity, water resistance, and thermo-responsive hydrophilic/hydrophobic were studied by SEM, DSC, and CA and so on.The membranous of blend composite and Semi- IPN were better than PNIPAM. The processed cotton had thermosensitivity, so that the processed cotton fabric had the characteristics of the functional materials. Its performance at the low temperature(below the LCST) was hydrophilic, and at the high temperature(above the LCST) was the hydrophobic.The water resistance of PU treated cotton fabric is better than of pure PNIPAM treated cotton fabric. In addition, the water resistance of composite materials treated cotton fabric were better than of pure PNIPAM treated cotton fabric.