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Epoxy/starch-modified nano-zinc oxide transparent nanocomposite coatings: A showcase of superior curing behavior

2017; Elsevier BV; Volume: 115; Linguagem: Inglês

10.1016/j.porgcoat.2017.11.016

1873-331X

Morteza Ganjaee Sari, Mohammad Reza Saeb, Meisam Shabanian, Mahroo Khaleghi, Henri Vahabi, Christelle Vagner, Payam Zarrintaj, Reza Khalili, Seyed Mohammad Reza Paran, Bahram Ramezanzadeh, Masoud Mozafari,

Carbon dioxide utilization in catalysis

A new class of transparent epoxy-based nanocomposite coatings containing starch-modified nano-zinc oxide (ZnO-St) is presented. ZnO nanoparticles physically decorated with starch carbohydrate polymer increased compatibility with epoxy chains and sterically prevented flocculation of ZnO nanoparticles. Surface characteristics of pristine ZnO and ZnO-St are studied by FTIR spectroscopy corroborating self-assembled starch molecules on ZnO surface until reaching a complete coverage. Curing behaviors of epoxy and transparent nanocomposites containing ZnO and ZnO-St are studied by the aid of nonisothermal calorimetric analyses at four heating rates to compare the curing enthalpies, onset temperatures, peak temperatures, and curing intervals of transparent coatings. The ZnO-St, particularly at low heating rate of 5 °C/min, prolonged curing (corresponding to ΔT increase of ca. 166 for epoxy to 200 °C for Zn-St/epoxy), and increased the amount of heat release (in the same order from 328 to 380 J/g) due to epoxide ring opening by starch hydroxyl groups. Such novel class of epoxy/ZnO-St nanocomposite coatings can be applied as top-coats because of their transparency. Additionally, from an environmental/biological standpoint, one should consider that starch is a carbohydrate polymer and ZnO is antibacterial, which may put more stress on the use of transparent nanocomposite coatings developed in this work.