I'm working on a project and I need to increase the surface energy of polypropylene. I want you to tell me a way in order to increase surface energy of polypropylene?
The surface of polypropylene has a low energy because it's most C-H bonds. These have no significant dipole moment and none of the atoms at the surface have lone pairs available to interact with external dipoles.
The usual way to increase the surface energy is to oxidise it to produce polar C-O-H groups. This is hard to do chemically because the surface is so inert, so it's usually done by plasma etching the surface with an oxygen plasma. This sounds complicated but the equipment to do it is surprisingly simple and widely available.
I used to plasma etch silica surfaces for similar reasons, but I have never worked on polypropylene so I can't advise you on the details e.g. pressures, etch times, etc. However a Google will find you hundreds of papers on the subject.