Acrylic materials, whether it be paint or plastic, are synthetic (man-made) compounds containing acrylic acid, which is an organic (not man-made) liquid. So acrylic acid isn't man-made, but...
yes, clear plastic is man-made and is very bad for the environment
Most are. There are a few natural polymers, like rubber and cellulose.
No.
man made plastic is made from petruelum