水性聚氨酯／纳米二氧化硅杂化材料的制备及性能

Preparation and Properties of Polyurethane/Silica Hybrid Emulsion

以三羟甲基丙烷(TMP)为内交联剂,合成了一种内交联的水性聚氨酯(WPU)预聚体,以KH550为偶联剂,加入亲水型纳米二氧化硅(A200),通过溶胶-凝胶过程合成了一种水性聚氨酯/纳米二氧化硅杂化材料(PUSi)。通过红外光谱(FT-IR)、热重分析(TG)和透射电镜(TEM)等测试对PUSi的结构和性能进行了研究,并研究了纳米SiO_2对PUSi杂化乳液粒径、形貌及PUSi胶膜力学性能、耐热性、耐水、耐介质性的影响。红外分析表明,WPU大分子和A200之间形成了化学键,溶胶-凝胶过程中形成了Si-O-Si结构。TG分析表明,A200的加入提高了材料的耐热性。当w(A200)由0%增至2.5%时,乳液粒径由80.3nm增至152.1 nm,膜的拉伸强度由8.5 MPa增加到23.6MPa,耐水性能得到提高,硬度亦相应提高。

Polyurethane prepolymer was synthesized with trimethylolpropane （TMP） as crosslinker, and hydrophilic nano-sized silica （A200） was added to the prepolymer with KH550 as coupling agent, then waterborne polyurethane/nano-silica hybrids （PUSi） was obtained by a sol-gel process. Solidified films of the waterborne polyurethane were prepared by casting emulsions on Teflon surfaces. The structure and performance of the PUSi films were studied by Fourier transform infrared spectrum（FT-IR） and thermogravimetric analysis （TGA）. The effects of A200 on the particle size and morphology of PUSi hybrid emulsion were studied. FT-IR analysis indicates the formation of chemical bond between waterborne polyurethane （WPU） and A200. TG indicates that A200 can improve thermal stability of PUSi films. As the mass fraction of A200 increases from 0 % to 2.5 %, the particle size of emulsion increases from 80.3 nm to 152.1 nm, the tensile strength of the films increases from 8.5 MPa to 23.6 MPa, water absorption of films decreases, and the hardness is also improved.