Collaboration will continue, and be "improved by leaving the EU".
Leaving the EU will make collaboration harder.
Result: Bad
How will it be improved? please let me know.
Movement of people will be harder (VISAs/Permits/etc), tariffs will be in place (extra costs), borders will become stricter (extra checks), etc.
All I can see is more friction between UK and EU.
If you disagree, or would like to add more details, please let me know.
You can suggest a reason for leaving the EU, or look at the other reasons.