Processes for preparing impact modifier powders

摘要

Processes for preparing a powdery high rubber impact modifier containing two or more populations of polymer particles having a total rubbery weight fraction of greater than 90 weight percent is provided. Also provided are various methods of preparing aqueous polymer particle dispersions having two or more populations of polymer particles having a total rubbery weight fraction of greater than 90 weight percent. These dispersions are spray-driable into a powder and are useful for increasing the impact strength of various matrix resins.