Plastic or Plastics? Singular or Plural?

Hi! I am confused when we mention something plastic, we use singular or plural? Because sometimes it is singular and sometimes it is plural but they indicate the same thing. For example:

(1)Seaweed has a big potential to place single-use plastics.
(2)Underwater seagrass in coastal areas appear to trap plastic.

are "plastic" and "plastics" interchangeable?

Question

Plastic or Plastics? Singular or Plural?

Hi! I am confused when we mention something plastic, we use singular or plural? Because sometimes it is singular and sometimes it is plural but they indicate the same thing. For example:

(1)Seaweed has a big potential to place single-use plastics.
(2)Underwater seagrass in coastal areas appear to trap plastic.

are "plastic" and "plastics" interchangeable?

Answer

The difference between plastic and plastics is usually if it is countable or uncountable.

(1)Seaweed has a big potential to place single-use plastics.(different types of plastics. It is countable)
(2)Underwater sea grass in coastal areas appear to trap plastic.(plastic in general)