First of all, I would like to thank you for taking your time to answer this question. Yes, I think its just a physical bond between them, because we can separate them. The PVDF thin film and polyester support are like two layers that merge together. And I wanted to know what kind is the physical force between these layers.
i think you mean the possible electrostatic interaction between PVDF and polyester
because polyester is a general term for a large class of organic compounds which include many polymers, so i have to use one example (poly(4-hydroxybenzoic acid) just as an example of the polyester to explain the possible electrostatic interactions with PVDF
I am attaching two figures, hope these figures may be helpful