Abstract: Process for the preparation of a functionalized polymer containing an additive, in which process there is formed a compound that contains, besides at least one blocked isocyanate group, a free amino, hydroxy or carboxy group; this compound is linked to an additive via the free amino, hydroxy or carboxy group in the additive; this additive linked to the compound mentioned is contacted with a polymer that contains at least one free amino or hydroxyl group, at a temperature above the polymer's melting point and at least above (150)° C., such that the blocked isocyanate group reacts with the free amino or hydroxy group of the polymer to form the functionalized polymer. The invention also relates to the intermediate products formed in the process and in the preparation thereof. Lasdy, the invention relates to functionalized polymers and polymer compositions containing the functionalized polymer.

Abstract: The invention relates to a process for preparing a high-molecular polyamide or polyester or copolyester by melt-mixing polyamide or polyester or copolyester having a lower molecular weight with a blocked diisocyanate having the following formula. wherein R=linear, branched or cyclo aliphatic C2-C20 or aromatic C6-C20 and B1, B2=Caprolactam, Imidazole, dimethyl-pyrazole, triazole, oxim, malonic acid ester, ethylacetylacetonate, phenol, cresol, aliphatic alcohol, secundary amine, hydroxy benzoic acid methyl ester. With the process according to the invention a permanent increase in the molecular weight of a polyamide is obtained within 2 minutes, whereas this takes at least 10 minutes under comparable conditions using a blocked isocyanate according to the state of the art.