聚吡咯-羧化壳聚糖复合物的合成及其对环氧树脂涂层防腐性能的改善

Preparation of polypyrrole-carboxylated chitosan composite and its improving the anti-corrosion property of epoxy resin coating

采用三氯化铁作为氧化剂,在羧化壳聚糖-对甲苯磺酸水溶液中原位生成聚吡咯-羧化壳聚糖(PPyCCS)复合物。傅里叶变换红外(FT-IR)分析表明,羧化壳聚糖(CCS)可与聚吡咯(PPy)发生接枝反应,生成PPyCCS复合物。利用X射线衍射(XRD)、扫描电子显微镜(SEM)考察了PPy-CCS复合物的结构及形貌,发现随着CCS含量的提高,复合物晶面间距不断增大,平均粒径显著减小。将定量PPy-CCS复合物(0.5%,质量分数)分散于环氧树脂中,利用电化学工作站研究了复合物对环氧树脂涂层防腐性能的影响。结果表明,PPy-CCS复合物能够显著降低环氧树脂涂层的腐蚀电流,提高其防腐性能;随着复合物中CCS含量的增加,促进了复合物在环氧树脂中的分散及其在金属表面的吸附成膜,从而进一步提高环氧树脂涂层的防腐性能。

Polypyrrole-carboxylated chitosan composite was prepared in situ in an aqueous solution of carboxyla-ted chitosan and p-toluene sulfonic acid using FeCl3 as the oxidizing agent. Fourier transform infrared spectros-copy（FT-IR） indicated that graft reaction took place between CCS and PPy to afford the PPy-CCS composite.The structure and morphology of the resulting composite were investigated using X-ray diffraction（XRD） andscanning electron microscope（SEM）. It was discovered that the interplanar spacing increased gradually and theparticle size decreased significantly with increasing the CCS content. Quantitative PPy-CCS composites（0.5wt~） were dispersed in epoxy resin. The influence of the composite on the anti-corrosion property of epoxyresin coating was studied by means of electrochemical workstation. The results indicate that PPy-CCS compositecan markedly reduce the corrosion current of epoxy resin coating and improve its anti-corrosion property. MoreCCS content facilitates dispersion of the composite in epoxy resin and film formation on the surface of metal,thus further improving the anti-corrosion property of epoxy resin coating.