(2) Each director, before entering upon the duties of office, shall take and subscribe to an oath that the director will honestly, faithfully and impartially perform duties as a director and disclose any conflict of interest the director may have in any matter to be acted upon by the board. A copy of the oath shall be filed with the secretary of the board. [1969 c.643 §6; 1971 c.23 §7; 1971 c.403 §4; 1975 c.605 §15]