What is the way to make slime block become not bouncy while remaining all his original properities, how to make slime block not bouncy?
Have a repeat command block with this:
/tp @a[x=23,y=42,z=14] 23 42 14
Note: the coordinates
23,42,14 are just placeholders for the coordinates representing one block above the slime block.
Depends on what you want to use said slimeblock for.
If you as a player don't want to bounce when you fall on it, just hold shift.
But if you don't want any entity to bounce on the block, you either have to do loads of programming like Fabian Röling mentioned or alternatively, you can just wait for the next update where the Honey Block comes out.
The Honey Blocks have the exact same properties of blocks sticking to it but it doesn't make entities bounce.