An incorporated board of trade, chamber of commerce, merchants’ exchange, or other kindred association may purchase or lease suitable grounds and erect thereon such buildings as its board of directors deems proper for its interest. It may lease any portion of such building which is not occupied by or needed for its immediate use. It may, by a two-thirds favorable vote of its board, sell and convey its real estate. It may borrow money and execute and sell, or otherwise dispose of, its bonds or obligations, secured by a mortgage of its property or otherwise. The president and the secretary of the association shall sign all such obligations and conveyances.