I wonder if double-sided can be used as an adverb as is the case with sentence below. I found this sentence on the internet .
This table was designed as double-sided foldable .
Not really. Because “double-sided” refers to the sides of the table (in this example) it needs to be placed correctly so that it modifies the word “table” and not anything else. As it is, it looks like “double-sided” is acting as an adverb to the word “foldable”. For example, if you said “these trousers are double-strength elasticated” it would suggest that the elastic used in them is double strength, not that the trousers were double-strength and elasticated.
You could say:
This double-sided table was designed as foldable.
This table was designed as double-sided and foldable.