Silicone bonding - Permabond POP can be used to prime the surface of the silicone, and then parts can be bonded with a cyanoacrylate.
The Dos and Don'ts of Working with Silicone Adhesives and Sealants
How to glue silicone rubber - Quora
Surface modification and adhesive-free adhesion of
How to glue silicone rubber - Quora
What glue should I use between polycarbonate and synthetic rubber on a phone case? - Quora
Bonding_Methods
What do you do if your PopSocket doesn't stick? - Quora
How to Properly Prepare Surfaces for Silicone Sealant Application
What are Silicone surfactants?