A designated chemical structure, determined through the analysis of elements and groups on the surface of conductive carbon black (CB), alcohol-soluble acrylic resin used for dispersion of conductive CB was successfully prepared based on the principles of similar structure complex well. The content of acrylic acid, glass transition temperature (T g ), molecular weight (M w ), self-crosslinking degree, and N-hydroxymethyl acrylamide content were investigated to optimize the electrical conductivity and dispersion effect of conductive CB in coating. The composites of acrylic resin and conductive CB were characterized by X-ray photoelectron spectroscopy for surface chemical structure on CB, scanning electron microscopy for morphology of conductive coating, Fourier transform infrared for groups in acrylic resin, and digital multimeter techniques for surface resistivity of conductive coating. The optimum surface resistivity of the acquired conductive coating could reach 600 ohm/sq, showing an excellent conductive property. Moreover, the conductive coating still maintained a lower resistivity after salt spray and weather resistance test. POLYM. COMPOS., 36:467-474, 2015. V C 2014 Society of Plastics Engineers
INTRODUCTIONConductive coatings are mainly required for static charge dissipation and electromagnetic interference (EMI) shielding [1][2][3][4][5]. EMI can cause critical problems such as influencing the normal running of various electronic instruments and deteriorating of human health [6,7]. The shielding of EMI in some devices has become a necessary issue as the regulations on EMI become more restrictive [8][9][10]. This could be solved through conductive coating coated on the surface of device. However, coatings are inherently nonconducting and would provide no shielding effect [6]. To produce a coating, which is conductive, conceptually, there are three methods possible to design conductive coating: (1) utilize conductive polymers as the continuous matrix; (2) incorporate conductive pigments at sufficient pigment volume concentration; and (3) combinations of both the methods above [3]. Conductive polymers such as polyacetylene, polypyrrole [11], and polyaniline are of interest in both academic and industry applications [1]. But most of them have difficult in processing with conventional methods [12]. Conductive coating prepared by incorporating conductive filler as the ease of chemical synthesis and processing is receiving more attentions.Acrylic resin has been widely investigated due to its suitable appearance, easy to coat, enough adhesive force, etc. However, the resistivity of acrylic resin was not enough to act as EMI, antistatic, or conductive material. This problem could be solved by filling conductive pigments in the acrylic resin. The common conductive fillers include electrically conductive carbon black (CB) [13], graphite, pure metal [14], conductive polymer, and metal powders [15]. Among these different types of conductive fillers, metals are often high in price, large in proportion, easy to oxide, ...