| Polyurethane foam is widely used because of its excellent propertiessuch as light mass, low density, high specific strength, low thermal conductivity, good electrical properties, good impact resistance. But because of the poor strength, the application of polyurethane foam can be limited in certain areas.In recent years, in order to overcome this shortcoming, many try to use some method to modify the polyurethane foam. Carbon nanotubes has good mechanical properties such as high strength, toughness etc., and it also has special structure characteristics such as small diameter and large ratio of length to diameter, which can be used as a good reinforcing material to polyurethane foam. But some problems also exist in the modification process, for exmample, CNTs can not easily disperse well in polymer matrix because of the inert of its surface, and easy agglomeration, which can not play a very good modification effect.In order to reduce the agglomeration of CNTs and improve the dispersion of CNTs in the polyurethane matrix, this topic use the method of chemical modification to graft the molecules with hydroxyl groups on the surface of CNTs, and through this, the excellent performance of CNTs also can play better. Using the reaction of esterification, glycerol and PHEMA are respectively grafted to CNTs to prepare CNTs hydroxylated on its surface, then use the CNTs to modify polyurethane foam. Through adding different amount of modified CNTs in polyurethane foam, we do a research on the effect law of CNTs content on pore structure,apparent density,mechanical performance of polyurethanefoam.Using the Fu Liye IR, thermogravimetry, Raman spectroscopy,scanning electron microscopy, transmission electron microscopy, differential scanning calorimetry and other methods to characterize the products. We adopt some methods to characterize the products such as the Fu Liye IR, thermogravimetry, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, differential scanning calorimetry. The research results show that, compared to pure polyurethane foam and pure polyurethane foam filled with untreated CNTs, the cell average diameter of polyurethane foam filled with surface hydroxylated CNTs decreases significantly and the compressive strength increases. This shows that surface hydroxylated CNTs has good dispersity in the polyurethane matrix than unmodified CNTs, which has obvious nucleation effect and can offer a better enhance performance. |
