I have stumbled across this web site a few times, and I’m finally getting around to posting about it.
The site is a glossary of terms relating to what is referred to in the industry as “wet-end chemistry” and covers pretty much all the additives and processes that are involved in papermaking up to the point where the paper is dried.
This includes a discussion of many of the retention agents that exist and what makes them work.
It is written in the form of a glossary rather than a tutorial, so you might have to read several pages and piece the information together in your mind to get a proper explanation of some topics.
One thing to note if you are trying to use Wikipedia as well: “Polyamine” does not mean the same thing in papermaking as it does in general chemistry. For chemists, this term is similar to things like “polyalcohol” which indicate a hydrocarbon with multiple functional groups of the same type (so a polyamine has multiple amine groups). For papermakers, the term refers to a polymer of a (single) amine, in the same way that “Polystyrene” refers to a polymer of styrene.
It is (in my opinion) a flaw in the naming system used for polymers that the name refers to the material that was used to make the polymer, rather than the name of the resulting repeating unit. It ignores the fact that the reaction that linked the polymer may have modified that character of the original material. Thus the (papermaker’s) polyamine is a polymer of dimethylamine, but the nitrogen in the amine group forms the link in the polymer chain so the polymer no longer contains any amine groups; they have been transformed into quaternary ammonia groups whose net positive charge is critical to the polymer’s use. (end of rant)
I’m not sure this web site is still maintained because I have found several broken links once I stray from the glossary proper.