Sir Dr. Nizar the attached article talking about your question

This is a very interesting question

You may can by dissolving LDPE in its solvent "toluene", and dissolving PVA in "water", and then mixing them together, you must use medium temp. when mixing.

After this testing using FTIR to see the difference in structure.

When mixing them together will be produce immiscible  soluton because LDPE is non polar and PVA polar polymer,

so, we can not single Tg

Dr,

Yes you can 

you may be can by

dissolving PVA  in "water" and LDPE in timely solvent and the mixing them together With additions to the improvement  the miscible of solution