My mother stayed, with the intention of waiting until I finished school. In the end she didnt last that long because she had an affair and ended the marriage when I was 17. Yes, it did interrupt my education briefly, but TBH living in that environment had left me in such a mess that I wasn't coping with 6th form anyway.
Just a couple of things I think you should consider: first of all, please don't make your children responsible for the fact that you are choosing not to leave at the moment. Don't fix responsibility for that in their life stage. They've got no choice here. You have.
Second is that living in that environment really ruined my health. I've been chronically ill since my early teens, as has my sibling. The stress of it has just ruined me. I've also got issues with anxiety and really have struggled to be a fully functioning adult. Every day you stay with him extracts a cost, for both of your daughters - the one who he openly hates and the one who has figured out a way to deal with him that helps her avoid the hate.
Finally you need to ask yourself what your daughter's will do once they are old enough to make their own choices. Do you think they will have contact with him, or cut him off? And what do you think their relationship with you will look like? At some point they will have to deal with the fact that you knowingly kept them in a home with a man who openly hated at least one of them. It's a really difficult thing to come to terms with. My mother has some relationship with my younger siblings, but with me, as the eldest who saw the most and the worst of it, the relationship is very difficult. I know what she did, and she knows what she did, and it's hard for us to have a relationship as a result.
Don't make them the reason you're staying. It isn't fair.
Do they want you to split up? Do you know how they feel about it?