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以二官能度端氨基聚氧丙烯和4种不同的二元异氰酸酯(HDI、IPDI、TDI、MDI)为原料,合成了异氰酸酯封端的聚脲预聚体,再用硅烷偶联剂KH550对预聚体进行改性,制备了一系列链段刚性不同的硅烷改性聚脲(SPUA)(H1~2、I1~2、T1~2、M1~2)。用FTIR、TGA、动态机械热分析(DMA)、力学性能测试、XRD对材料的结构和性能进行了表征,并讨论了不同刚性链段对材料性能的影响。结果表明,当n(NCO)/n(NH2)为1.1时,随着SPUA链段刚性的增强,材料失重5%的温度(T5%)从H1的319.5℃上升到M1的334.1℃,失重50%的温度(T50%)从H1的390.1℃上升到M1的400.9℃,最大失重速率时的温度(Tmax)从H1的395.0℃上升到M1的405.5℃;材料的拉伸强度逐渐增大,从H1的2.78 MPa提高到M1的4.80 MPa,而韧性则逐渐下降,断裂伸长率从H1的337%减少到M1的224%;玻璃化转变温度(Tg)逐渐上升,从H1的-65.8℃上升到M1的-57.7℃。
An isocyanate-terminated polyurea prepolymer was synthesized from bifunctional amino-terminated polyoxypropylene and four different binary isocyanates (HDI, IPDI, TDI, MDI) and then prepolymerized with prepolymerized A series of silane modified polyureas (H1 ~ 2, I1 ~ 2, T1 ~ 2, M1 ~ 2) with different rigidities were prepared. The structure and properties of the materials were characterized by FTIR, TGA, DMA, mechanical properties and XRD. The effects of different rigid segments on the properties of the materials were also discussed. The results showed that the temperature (T5%) of 5% weight loss increased from 319.5 ℃ of H1 to 334.1 ℃ of M1 with the increase of rigidity of SPUA chain when n (NCO) / n (NH2) was 1.1. (T50%) increased from 390.1 ℃ of H1 to 400.9 ℃ of M1, and the maximum weight loss rate (Tmax) increased from 395.0 ℃ of H1 to 405.5 ℃ of M1. The tensile strength of the material gradually increased from H1 increased from 2.78 MPa to 4.80 MPa for M1, while the toughness decreased gradually. The elongation at break decreased from 337% of H1 to 224% of M1. The glass transition temperature (Tg) increased gradually from -65.8 ℃ of H1 To -57.7 ° C for M1.