全氢聚硅氮烷涂层制备及其性能

以重复单元为-(SiH2NH)-的全氢聚硅氮烷(PHPS)前驱体溶液为原料,采用水汽固化方式制备新型低表面能防护涂层。通过接触角测试、硬度及附着力等力学性能试验研究了PHPS固化过程中温度与时间对涂层性能的影响。使用傅里叶红外光谱仪(FTIR)与扫描电镜(SEM)对PHPS涂层化学结构以及微观形貌进行表征观察,并通过动电位极化曲线研究了最佳工艺制备的涂层的耐蚀性能。研究表明,温度200℃、时间2h为PHPS水汽固化的最佳工艺参数。在温度200℃、时间2h固化制备的PHPS涂层表面平整致密,无明显缺陷且与基体结合良好,PHPS涂层接触角最大为105°,计算得出其表面自由能为18.74mN·m-1,涂层硬度达到9H,附着力等级达到0级。由动电位极化曲线可知,浸泡48h后涂层的电流密度为2.136×10-7A·cm-2,基体的电流密度为1.336×10-4A·cm-2,腐蚀电流密度大大降低,涂层保护效率高达99.84%。

Preparation and Properties of Perhydropolysilazane Coating

A new low-surface energy protective coating was prepared by vapor-solidification using a per. hydropolysilazane(PHPS)precursor solution with a repeating unit of -(SiH2NH)- as a raw material. The effects of temperature and time on the performance of the PHPS coating during the curing process were investigated by contact angle tests,mechanical properties tests such as hardness and adhesion. The chemical structure and morphology of the PHPS coating were characterized by Fourier transform infrared spectroscopy(FTIR)and scanning electron microscopy(SEM). The corrosion resistance of the coating prepared by the best process was studied by the potentiodynamic polarization curve. The results showed that the best process parameters were temperature of 200 ℃ and time of 2 h for PHPS curing. The surface of the PHPS coating prepared by curing at 200 ℃ for 2 h was flat and compact,without obvious defects and well bonded to the substrate. The maximum contact angle of the PHPS coating was 105 °,and the surface free energy was calculated to be 18.74 mN·m-1,the hardness of the coating was 9 H and the ad. hesion grade reached 0. According to the dynamic potential polarization curve,the current density of the coating after immersion for 48 h was 2.136×10-7 A·cm-2 and the current density of the substrate was 1.336×10-4 A·cm-2. The corrosion current density was greatly reduced and PHPS coating protection effi? ciency was up to 99.84 %.