According to https://en.oxforddictionaries.com:

"According to traditional guidelines, disinterested should never be used to mean <em>‘</em>not interested’ (i.e. it is not a synonym for uninterested) but only to mean ‘impartial’, as in 'the judgements of disinterested outsiders are likely to be more useful'. Ironically, the earliest recorded sense of disinterested is for the disputed sense. Today, the ‘incorrect’ use of disinterested is widespread: around a quarter of citations in the <a href="https://en.oxforddictionaries.com/explore/the-oxford-english-corpus" title="The Oxford English Corpus"><em>Oxford English Corpus</em></a> for disinterested are for this sense."

disinterest

The state of not being influenced by personal involvement in something; impartiality.
‘I do not claim any scholarly disinterest with this book’