METHOD OF MODIFYING THERMOPLASTIC POLYMER, METHOD OF PREPARING IMPROVED MULTIFUNCTIONAL VISCOSITY MODIFIER, AND METHOD OF PRODUCING FUNCTIONALYZED THERMOPLASTIC POLYMER Russian patent published in 1998 - IPC

FIELD: polymer production. SUBSTANCE: modification is carried out in extruder reactor with multiple reaction zones. Each one has means to load reagents, to mix reagents with polymer, and to remove by-products or unreacted reagents. A multitude of consecutive reactions are carried out in one reactor in which polymer melt reacts with the first reagent group, usually in absence of solvent or diluent, after which reaction by- products and unreacted reagents are removed from the melt, and then polymer melt reacts with the second reagent group until desired product is obtained. Removal of polymer melt or neutralization of volatile impurities in one reaction are completed before next reaction is commenced. Because of that, polymer melt entering reaction zone is relatively free of possible impurities from foregoing reaction zone. EFFECT: increased purity of polymer product. 25 cl, 1 tbl, 19 ex