Most normal glue will NOT work on acrylic.
The recommended glue is what is known as a solvent cement. This melts the acrylic and then reforms a bond between the two pieces as it dries. If done correctly, the bond is as strong as the acrylic itself.
The product we use is called Acribond 110. It is available in a range of sizes. We do not sell this glue, but a quick google search will find many suppliers.