I wouldn't worry about poly-cotton fabric, use it up along with your cottons. About 15 to 20 years ago, that is all we could buy for sewing clothes or quilts. Then cotton was back and now that is all we can get.
Those who didn't want to iron, bought poly cotton clothes. Bachelors especially, they didn't have MOM handy to iron their shirts and some were drip dry. That is where you wash the clothes, squeeze out as much water as you can, hang the piece on a hanger over the bathtub so the rest of the water can drip out. When dry, they didn't need ironing.
Use it up and don't worry about it, not worth it.
Carol J.