TAILIEUCHUNG - Quality reinforcement of electroplating Zinc coatingselectrodeposited from cyanide free alkaline solution by polyamine 70.000 and polyvinyl alcohol 16.000
The scanning electron microscope (SEM) images showed that the size of zinc grains decreased with the presence of polyamine and polyvinyl alcohol with smoother surface of zinc coating. The polarization measurements also revealed that the coatings with the presence of polyamine or polyvinyl alcohol possessed higher value of polarity degree. This result is in good agreement with the result obtained from SEM images. | Vietnam Journal of Science and Technology 55 (5B) (2017) 18-26 QUALITY REINFORCEMENT OF ELECTROPLATING ZINC COATINGSELECTRODEPOSITED FROM CYANIDE FREE ALKALINE SOLUTION BY POLYAMINE AND POLYVINYL ALCOHOL Truong Thi Nam1, 2, Le Ba Thang1, 2 , Nguyen Thi Cam Ha3, Hoang Thi Huong Thuy4, 5, Hoang Van Hung4, * 1 Institute for Tropical Technology, Vietnam Academy of Science and Technology 18 Hoang Quoc Viet, CauGiay, Ha Noi, Viet Nam 2 Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18, Hoang Quoc Viet, CauGiay, Ha Noi, Viet Nam 3 Faculty of Chemistry, the VNU University of Science - National University Ha Noi, 19 Le Thanh Tong, Hoan Kiem, Ha Noi 4 Faculty of Chemistry, Hanoi National University of Education, 136 Xuan Thuy, Ha Noi 5 Hong Duc University, 565 Quang Trung, Thanh Hoa City, Thanh Hoa Province * Email: hunghv@ Received: 1 August; Accepted for publication: 4 October 2017 ABSTRACT Zinc coatings have been deposited electrochemically from cyanine free alkaline solutions containing zinc ions with the presence of polyamine and polyvinyl alcohol at different contents. The scanning electron microscope (SEM) images showed that the size of zinc grains decreased with the presence of polyamine and polyvinyl alcohol with smoother surface of zinc coating. The polarization measurements also revealed that the coatings with the presence of polyamine or polyvinyl alcohol possessed higher value of polarity degree. This result is in good agreement with the result obtained from SEM images. Keywords: zinc coating, polyamine, polyvinyl alcohol, alkaline cyanide free bath. 1. INTRODUCTION Zinc coatings have been used extensively in different industrial fields as protective coatings for large quantities of items composed of steel such as wires, strips, sheets and tubes. These coatings commonly produced by electrode-position from alkaline cyanide-containing solutions, alkaline cyanide-free .
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