I personally don't think paper money will completely disappear any time in the near future. It is true that electronic transactions have become more and more common over the last few decades and I see no reason why this trend will not continue. We may even get to the point where paper money transactions become incredibly rare. At that point, the tables could turn and what we now consider paper money may actually act as the backing to our electronic currency, the way the gold standard once backed paper money.
With electronic money there is question of privacy security and many people don't believe in electronic money they still prefer physical money and this will prevail in the future too.