Can you electrically charge stuff with plastic? Yes, this is possible. It's called the triboelectric effect and it's what you see when your socks get a electrostatic charge after being in the dryer.

Is plastic positively or negatively charged?

Choice of the names negative or positive is arbitrary. If you rub a glass rod with a cloth, the charge produced on the glass rod is called positive, whereas when a plastic rod is rubbed with a cloth, the charge produced on the plastic rod is negative.

How does plastic get charged?

For example, when a plastic rod is rubbed with a duster, electrons are transferred from one material to the other. The material that gains electrons becomes negatively charged. The material that loses electrons becomes positively charged.