缓蚀型天然气减阻剂Mannich碱-苯甲酸盐的合成及其成膜性能

目的合成一种缓蚀型天然气减阻剂,满足新旧天然气管道增大输气量、季节性调峰和安全稳定运行的需求。方法通过亲核加成反应,合成缓蚀型天然气减阻剂——1,4-双(苯基亚甲基-N,N'-二正丁基胺)哌嗪四苯甲酸盐(BPDBPB)。采用傅里叶变换红外光谱(FTIR)、~1H核磁共振波谱(NMR)和元素分析(ELA)对化合物进行结构表征,应用扫描电子显微镜(SEM)、电化学阻抗法和极化法对其成膜性能和稳定性进行测试。结果 FTIR,~1H NMR和ELA测试证实,所得到的产品为设计的目标化合物。减阻剂BPDBPB喷涂在钢片表面后形成了一层致密的保护膜,使钢片表面粗糙程度大大降低。电化学阻抗测试中,BPDBPB在铁电极表面成膜后,自高频区向低频区形成了两个连续的容抗弧,高频区形成的容抗弧较小,低频区形成的容抗弧较大。电化学极化测试中,与空白电极相比,BPDBPB成膜后的阳极极化曲线略变陡,自腐蚀电位值增大了0.092 V,自腐蚀电流减小了0.71×10~(-5)A。结论所合成的减阻剂具有较好的成膜性,可大幅度降低钢片表面的粗糙度,且所形成的膜结构具有较好的稳定性。

Synthesis and Film-forming Property of Drag Reducing Agents with Inhibition Performance for Natural Gas Based on Mannich Base-Benzoate

Objective Drag reducing agent with inhibition performance was synthesized, in order to meet the requirements of increasing the rate of gas transmission, seasonal variety and safe operation. Methods A novel drag reducing agent with inhibition performance, 1,4-bis(phenyl methylene-N,N'-din-butyl amine) piperazine benzoate (BPDBPB) was synthesized by nucleophilic addition reaction. The structure of BPDBPB was characterized with Fourier transform infrared spectroscopy (FTIR), Nuclear magnetic resonance spectroscopy (1H NMR) and elemental analysis (ELA). Film-forming property and stability were assayed by Scanning electron microscope (SEM), electrochemical impedance and polarization method. Results The results of FTIR, 1H NMR and ELA tests confirmed that the product was the target compound. Spraying BPDBPB on the surface of the steel sheet led to formation of a dense protective film, which largely decreased the roughness of the steel. In electrochemical impedance test, the DRA formed two capacitive arcs successively from high frequency region to the low frequency region. The capacitive arc formed in the high frequency region possessed smaller diameter, while that formed in the low frequency region had larger diameter. In the electrochemical polarization test, compared to blank polarization, the anodic polarization curve was slightly steepened, and the self-corrosion potential was increased by 0. 092 V while the value of self-corrosion current was decreased by 0. 71×10 -5 A. Conclusion The DRA synthesized possessed good film-forming property, and largely reduced the roughness of the steel surface. And the film structure formed possessed good stability.