Corrosion monitoring of polymeric materials using optical fiber.

本研究以胺固化型环氧树脂为材料，以BTB和BPB为pH指示剂，研制了检测酸碱溶液渗透到树脂中的传感器，通过对含有树脂的pH指示剂在硫酸和水中的渗透变色的检测结果表明，BTB在硫酸和水的渗透下变色。另一方面，BPB仅通过硫酸的渗透就改变了颜色。通过对含有BTB的样品在硫酸中浸泡的横截面的研究，观察到变色层内部的逐渐变色。推测水对树脂的渗透比对硫酸的渗透更远，S元素能谱图和卡尔费休法水分分析证实了这一预期。成功地实现了前人研究结果的可视化，即水的渗透速度快于溶质的渗透速度。在此基础上，对有机酸根离子…进行了检测此外，还研究了对材料侵彻影响较大的D。制作了含有样品的pH指示剂，并将其浸泡在氯乙酸中。BTB和BPB加入树脂后均发生颜色变化，透过率在450~500 nm范围内降低，透过率增加600 nm。将光纤置于浸渍乙烯基酯树脂的玻璃之间，树脂固化。然后，在光纤中加工狭缝，并在狭缝中填充含有环氧树脂的pH指示剂。该传感器埋入玻璃纤维毡中，玻璃钢的一侧与氯乙酸接触。对光通过光纤的透过率进行了监测，从BTB传感器上只观察到了500 nm处透过率的下降。而BPB传感器的透过率降低了500 nm，透过率增加了600 nm。从这一结果可以看出，使用BPB作为pH指示剂的光纤传感器更可信。较少

In this study, the development of sensor detecting the penetration of acidic or alkaline solution into the resin was objected.Amine cured type epoxy resin was used as material and BTB and BPB was used as pH indicator.From the result of examination of the color change of pH indicator containing resin immersed in sulfuric acid, BTB changed its color by penetration of both sulfuric acid and water. On the other hand, BPB changed its color by only the penetration of sulfuric acid. The gradual color change was observed inside of color changed layer by investigation of the cross section of BTB containing specimen immersed in sulfuric acid. It was expected that the water penetrates into the resin further than the sulfuric acid and the expectation was confirmed by the EDS mapping of S element and water content analysis by Karl Fischer method. The visualization of the result of previous study "the water penetrates faster than the solute" was succeeded.After that, the detection of the organic aci … More d, that has a large influence of penetration into the materials, was investigated. The pH indicator containing specimen was manufactured and immersed in chloroacetic acid. Color change was observed both BTB and BPB containing resin and the decrease of transmittance of 450-500 nm and the increase of 600 nm was observed.Next, the thin optical fiber sensor enable to apply between the layer of FRP was manufactured. The optical fiber was put between glass cross impregnated in vinyl ester resin and the resin was cured. Then, the slit was machined in optical fiber and the slit was filled with pH indicator containing epoxy resin. This sensor was embedded in glass mat type FRP and one side of FRP was contacted to chloroacetic acid. The transmittance of the light passing the optical fiber was monitored.From the BTB sensor, only the decrease of the transmittance of 500 nm was observed. On the other hand, BPB sensor had both the decrease of transmittance of 500 nm and the increase of 600 nm. From this result, it can be said that optical fiber sensor using BPB as pH indicator is more trustful. Less