METHOD OF MODIFYING SURFACE OF POLYETHYLENE TEREPHTHALATE GRANULATE Russian patent published in 2013 - IPC C08G63/91 C08G63/88 C08G63/183 C08J7/12 C08F8/00 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of modifying the surface of a polyethylene terephthalate granulate in order to increase heat-, light-, wear- and hydrolytic resistance, as well as reduce gas permeability of polymer materials. The method involves treating the surface of polyethylene terephthalate with a modifier while heating, wherein the modifier used is a fluorine-containing prepolymer with isocyanate groups in amount of 2 pts.wt per 100 pts.wt polyethylene terephthalate of general formula: , n=5-7, m=2-4. Said modifier is obtained by reacting polymethylene polyphenylene isocyanate with content of isocyanate groups of 29.5-31.0% with trifluoroacetic acid in the presence of catalytic amounts of di-n-butyl tin dilaurate with molar ratio of reactants of 1:0.3:0.003, respectively, in a medium of o-dichlorobenzene at temperature of 70°C, ultrasound frequency of 40 kHz for 6 hours. Modification is carried out in a medium of chlorobenzene at 150°C for 4 hours in the presence of catalytic amounts of di-n-butyl tin dilaurate.

EFFECT: modifying the surface of a polyethylene terephthalate granulate using said method enables to widen the operating temperature range of articles made from polyethylene terephthalate.

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