I have a showewr head that I need to remove. A simple wrench does not work because it looks like some type of pipe glue/bonding material was put on when it was installed. Is there any sort of chemical I can use to loosen this glue so I can remove the shower head?

It would help to know what glue was used. Can you put a wrench on the head or is it smooth? Web wrenches use a canvas fabric that can get pretty tight on smooth surfaces. You could try Goof Off and then maybe a heat dgun. Don't use open flame near Goof Off. If nothing works you can unscrew the stem from the wall and replace the stem and the head.