As nouns the difference between sentimentality and sensationalism

is that sentimentality is an act of being sentimental while sensationalism is the use of sensational subject matter, style or methods, or the sensational subject matter itself; behavior, published materials, or broadcasts that are intentionally controversial, exaggerated, lurid, loud, or attention-grabbing. Especially applied to news media in a pejorative sense that they are reporting in a manner to gain audience or notoriety but at the expense of accuracy and professionalism.