As I know, we don't have additive recycling but we have polymer recycling.

recycling additives may refer to additives which are used in recycling polymers. but we couldn't use them separately.

Thank you John for citing my paper.

Of course the question refers to additives for polymer recycling.

Clays are also nanofiller additives which enhances the mechancial and thermal properties and also helps the degredation of the polymer can be used recycling additive.

for recylcling the polymer, you need to choose such type of material. but for degradation of polymer, there are some additives are there.

There are additives that can be used to ovoid polymers degradation  during recycling such as chain extenders. Their choice depend on the polymer structure.