| With the development of the economy, the road construction has been expanding rapidly in our country. The cement concrete road with its strong bearing, long service life and the low cost advantages of daily maintenance, it has always been dominant in our country. However, the quality of caulking materials is directly related to the lifetime of cement concrete road. Therefore, the research of cheap and high performance caulking materials is hard in the world. Now, the silicone caulking glue is the best cement concrete pavement joints in the world, it has high performance, but the cost is too much; Therefore, the most widely used is polyurethane caulking glue in our country, and the polyurethane modified with polysiloxane.It has high cost performance. Every coin has two sides. The crossing-linking group of polyurethane caulking glue is isocyanate, it will be reaction of water and the carbon dioxide will be appeared, it will affect the quality of caulking materials.In order to solve this problem, the polyurethane caulking glue with silicon hydroxyl-terminated were prepared. The modified polyurethane caulking glue cross-linked by silicon hydroxyl and methoxy group at room temperature. The Cross-linking is easier, faster and more thoroughly. The modified polyurethane joints cross-linked without other products or gases. In the process of the reaction without solvent, not only environmental protection, but also and the cost is lower than the silicone rubber.The research mainly includes the following aspects:(1)The preparation of new polyurethane caulking glue modified by siliconeThe polyurethane prepolymers of NCO-terminated was prepared, afterwards, the polyurethane prepolymers of silicon hydroxyl-terminated was prepared by polysiloxane of hydroxyl-terminated. The plasticizer, cross-linking agent and kinds of packings were mixed to prepare the new polyurethane caulking glue modified with polysiloxane.(2)The research of the new polyurethane caulking glue's properties modified by siliconeDiscussing the properies of different kinds and content of polyether; Discussing the properies of different content of OH-PDMS; Discussing the properies of different content of CaCO3 and SiO2. The result showed that, the ratio of polyether 2000/3050 is 13/11, the ratio of NCO/OH is 2.0,the ratio of Si-OH/NCO is 1.6,When polyurethane is 100%,crosslinking agent is 5-7%,CaCO3 is 20-40%,SiO2 is 6-10%,plasticiser is 0-4%,catalyst is 0.010-0.015%, the performance of polyurethane caulking glue modified with polysiloxane is best. The test result of tensile strength is 0.66 MPa, the percentage of breaking-elongation is 433, the bonding strength is 0.48 MPa.(3)The synthesis and characterization of the hyperbranched polyaminoesterThe different generations of hyperbranched polymer were prepared by trimethylolpropane and AB2-type monomer. IR, hydroxyl value, element analysis and TGA were tested for the hyperbranched polymer. The results showed that the hyperbranched polymerr has a mass of hydroxyl group, excellent mechanical properties and good thermal stability.(4)The modification of hydroxyl-terminated hyperbranched polymerThe hydroxyl-terminated hyperbranched polymer was modified by 3-(trimethoxysilyl)propyl isocyanate. IR,TGA and measurement of hydroxyl value was tested for the hyperbranched polymer. The results show that the modified hyperbranched polymer has a mass of methoxy and a few hydroxyl groups.(5)The research of the polyurethane caulking glue's properties modified by hyperbranched polymerUsing G1,G2,G3 hyperbranched polymer modified by 3-(trimethoxysilyl)propyl isocyanate instead of crosslinking agent. The result showed that, when the adding amount of G2 was 4.5%, the performance of the polyurethane caulking materiaks is best. The test result of tensile strength is 0.98 MPa, the percentage of breaking-elongation is 489, the bonding strength is 0.68 MPa. |
PDF Full Text Request