###### Abstract  
A series of novel anti-corrosive coatings were synthesized successfully. Water-borne polyurethane (WPU) was synthesized using polyethylene glycol and modified by grafting benzotiazole (BTA) as a pendant group (WPU-g-BTA) and N-alkylated amines (ethylene diamine (A), diethylene triamine (B), triethylene tetramine (C)) as side-chain extenders. Fourier-transform infrared spectroscopy, thermogravimetry, and dynamic mechanical analyses were used to characterize the structural and thermomechanical properties of the samples. A gas permeability analyzer (GPA) was used to evaluate molecular barrier properties. The corrosion inhibition performance of WPU-g-BTA-A, WPU-g-BTA-B, and WPU-g-BTA-C coatings in 3.5 wt% NaCl solution was determined by electrochemical measurements. WPU-g-BTA-C coating synthesized with a high cross-linking density showed superior anticorrosive performance. The as-prepared coatings exhibited a very low icorr value of 0.02 uA.cm\({}^{-2}\), a high Ecorr value of \(-\)0.02 V, as well as excellent inhibition efficiency (99.972%) and impedance (6.33 \(\Omega\)) after 30 min of exposure. water-borne polyurethane; benzotriazole; N-alkylated chain extenders; anti-corrosion Article Preparation and Characterization of Water-borne Polyurethane Based on BenzotriazoleCorrosion inhibitors generally contain specific characters such as nitrogen, sulphur, oxygen, and so on, or some special unsaturated functional groups, etc. They have the advantages of simple operation, significant corrosion protection effect, and small dosage. Therefore, they have received extensive attention from corrosion protection scientists [22; 23; 24]. For many years, hexavalent chromates were used as traditional inhibitors, but their application was restricted due to their toxic nature. Recently, heterocyclic molecules, such as benzotriazole (BTA), have been widely used as corrosion inhibitors [25; 26]. In 2014, [PERSON] et al. reported the excellent corrosion protection of BTA-loaded raspberry-like hollow microspheres with and without WPU films [26], in which copper electrode coated by WPU film containing BTA-loaded raspberry-like hollow microspheres showed a corrosion inhibition efficiency of 84.4% after 30 h of immersion in alkaline meium (pH = 10). [PERSON] et al. studied polyurethane and acrylic paints doped with halolysis loaded with benzotriazole, 2-mercaptoethanolbenzimidazole, and 2-mercaptoethanolbenzothiazzole as corrosion inhibitors [27]. [PERSON] et al. reported different smart sensing coatings such as PDVB-graft-P(DVB-co-AA)-BTA, Halloysite-BTA, and IPDI@PU/PUF for the evaluation of corrosion inhibition efficiency [28]. Scholars have also developed systems based on silica by using nano-containers, nano-capsules, and microspheres loaded with BTA for corrosion inhibition [29; 30]. Coatings also undergo photo-oxidative degradation upon UV exposure. In this regard, various strategies are used, including the addition of organic UV absorbers (UVA) and hindering amine light stabilizers or functional particles (TiO\({}_{2}\), ZnO) [31; 32; 33; 34]. Common chemical classes of organic UVA are benzophenones, benzotriazoles, triazines, malonates, and oxalanilides [35]. [PERSON] et al. [36] and [PERSON] et al. [37] used nano ZnO and hydroxyphenyl triazine as UV stabilizers in polymer coatings. [PERSON] et al. used ZnO/TiO\({}_{2}\)[38], and [PERSON] reported the use of benzotriazole and triazine [39] as UVA in automotive plastic coating. The introduction of side chain improves the properties and flexibility of the WPU main chain [40]. In particular, methyl group [41], long-branched fatty acids [42], organo-phosphorous groups [43], and siloxane groups [44] have been used as side chains. The effects of chain extenders on the adhesion and mechanical properties of WPU films have also been studied [45]. [PERSON] et al. reported a series of WPU with 3-(2-aminoethylamino)propyldimethoxyylsilane (APTS) as chain extender [46]. [PERSON] et al. reported WPU with cystamine as chain extender [47]. In 2016, [PERSON] et al.