Polymer blends containing thermoplastic and cross-linked reaction product from polyaddition or polycondensation

A polymer blend comprising:

• A) a thermoplastic polymer selected from the group consisting of polycarbonates, polyester carbonates, polyesters and polyam ides, or a monophasic mixture of a plurality of thermoplastic polymers selected from the group consisting of polycarbonates, polyester carbonates, polyesters and polyam ides,
• B) optionally at least one further thermoplastic polymer which is different from component A and is not completely miscible with component A,
• C) 1 to 200 parts by weight, based on 100 parts by weight of component A, of a cross-linked or branched polymer,
• wherein component C is formed in situ in an extruder or kneader during the melt compounding of component A and optional further components in the presence of
• C.1 a first monomeric or oligomeric component comprising functional groups C.1.1 and
• C.2 a second monomeric or oligomeric component comprising functional groups C.2.1 which are different from C.1.1,
• by polyaddition or polycondensation in a reaction of the functional groups C.1.1 of component C.1 with the functional groups C.2.1 of component C.2,
• where components C.1 and C.2 are
• difunctional or higher-functionality compounds or are mixtures of one or more difunctional or higher-functionality compounds,
• and wherein at least one of components C.1 and C.2 comprises higher-functionality compounds.