Corrosion monitoring of polymeric materials using optical fiber.

在本研究中，研究了检测酸性或碱性溶液渗透树脂的传感器的发展。以胺固化型环氧树脂为材料，以BTB和BPB为pH指示剂。从含树脂pH指示剂浸在硫酸中颜色变化的检测结果来看，BTB在硫酸和水的双重作用下发生了颜色变化。另一方面，BPB仅通过硫酸的渗透就能改变其颜色。通过对浸在硫酸中含BTB试样的截面进行观察，发现变色层内部颜色逐渐发生变化。通过S元素能谱图和卡尔费休（Karl Fischer）法的含水量分析证实了这一预测。成功地将前人研究“水比溶质渗透快”的结果可视化。在此基础上，研究了对材料渗透有较大影响的有机酸的检测。制作含标本的pH指示剂，浸入氯乙酸中。BTB和含BPB树脂均有颜色变化，在450 ~ 500 nm处透光率下降，在600 nm处透光率增加。其次，制造了应用于玻璃钢层之间的薄光纤传感器。将光纤置于浸渍乙烯基酯树脂的玻璃十字之间，并对树脂进行固化。然后在光纤中加工狭缝，并用含环氧树脂的pH指示剂填充狭缝。该传感器嵌入玻璃垫型玻璃钢中，玻璃钢的一侧与氯乙酸接触。对通过光纤的光的透射率进行了监测。从BTB传感器来看，仅观察到500 nm处透光率下降。另一方面，BPB传感器的透光率降低了500 nm，增加了600 nm。从这个结果可以看出，使用BPB作为pH指标的光纤传感器是更可靠的。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