What type of styrene by any chance?
Certain plastic requires specific glues for best adhesion.
Typically it's hard to get a long-lasting attachment with plastic to fabric.
You can use contact cement which is generally the industrial standard in the costuming department, but you can also use snap fasteners or as others have said, velcro.
Typically you would design a webbing (Like a vest of straps) and mount the plates onto the webbing.
Also, if you intend to wear the fabric, I would not use superglue. It hardens the fabric acting like how fibreglass matting is to resin. It hurts and stabs at your skin.