Rotate object away from the player

I’m trying to make an object look away from the player (read “main camera”), but for some reason it’s not rotating. When i use transform.lookAt() it works fine, but i want to interpolate. Current code is:
void Update() {
Quaternion lookRot = Quaternion.LookRotation(transform.position - Camera.main.transform.position);
transform.rotation = Quaternion.Slerp(transform.rotation, lookRot, interpolationTime);
}

So what’s wrong?

where are you updating the interpolationTime?? If it remains with a value of 0.0f, the object never rotates. You can update it like so:

interpolationTime += Time.deltaTime;

If interpolation time starts at 0.0f and you do the above at the end of the update method. It will update every frame with a new step somewhere along the interpolation and it will go from the start rotation to the end rotation in 1 second.