As far as I know, the only difference between predicate logic and propositional logic is the usage of quantifiers and expressing propositions in the way which we use predicates.
Also, we know that we can use rules of propositional logic instead of quantifiers; for example we can say $P(x_1)\wedge P(x_2) \wedge ...\wedge P(x_n)$ instead of $\forall x P(x)$, when we know that $x_1, x_2, ..., x_n$ are all of the elements of the domain. But obviously it is more convenient to use $\forall x P(x)$.
So, can we say that predicate logic is nothing more than propositional logic with some notations which bring us easiness to work with?