Study On The Preparation And Properties Of HTPB/EP Polyurethane

Polyurethane is a kind of widely used materials. In many types of polyurethane, hydroxyl-terminated polybutadiene polyurethane based polyurethane(HTPB based PU) is widely applicated in various fields due to its superior performance. However, with the development of the society and the progress of science and technology, the requirement for the properties of materials becomes more and more strict. Therefore, the application is limited to a certain extent. Thus it is of great practical significance to study on the modification of HTPB based polyurethane.In the paper, epoxy resin(EP) was used for the modification of HTPB based polyurethane. The influence of different factors on the performance was investigated, such as the addition of epoxy resin and ring-opening modified epoxy resin with acid and silicone, the content of ring-opening modified epoxy resin, as well as the chain length of organic acid used for the ring-opening reaction. Concrete research content is as follows:The HTPB based polyurethane materials were prepared by the method of prepolymer. In the process of preparing polyurethane with HTPB, polyether polyols N403 and TDI as the raw materials, ring-opening modified epoxy resin was added into the system, and combined with each other by chemical bonds, which curing to polyurethane materials. Both the modification of epoxy resin and the synthesis of polyurethane were characterized by fourier transform infrared spectrum. The contact angle analysis and EDS element analysis showed that the polyurethane materials presented different polarity on the base plate and the air surface, and the components was regularly uneven distribution along the thickness direction. TG and DSC thermal analysis showed that the material had a good thermal stability.The mechanical properties of the HTPB based polyurethane materials were studied and the results showed that the addition of ring-opening modified epoxy resin could improve the mechanical properties.In a certain range, with the increase of the ring-opening modified epoxy resin content, the tensile strength and elongation at break gradually enhanced. When the epoxy resin content reached 15%, comprehensive performance was better. The tensile strength reached to 6.34 MPa, and the elongation at break reached to 131.67%. The mechanical properties were also affected by the chain length of organic acid used in the ring-opening of epoxy resin. As chain length increased, the mechanical properties increased.The addition of the ring-opening modified epoxy resin also could improve the adhesive properties. With the increase of the ring-opening modified epoxy resin, the adhesive properties enhanced. After adding epoxy resin, the adhesive rubber had different degree of deformation. When the epoxy resin content reached 30%, the result was destroyed by sticky materials while the adhesive surface is still in good condition, which proved that the adhesive properties were excellent. The adhesive properties were also affected by the chain length of organic acid used in the ring-opening of epoxy resin. As chain length increased, the adhesive properties increased.The solvent resistance was studied and the results showed that the addition of ring-opening modified epoxy resin could improve the solvent resistance in different solvent. With the increase of the ring-opening modified epoxy resin, the solvent resistance enhanced. The solvent resistance was also affected by the chain length of the organic acid used in the ring-opening of epoxy resin. As chain length increased, the solvent resistance increased. In addition, after 20 days of immersion in water, the weight gain rate is still close to 0, which proved that the materials had a good resistance to water.