A process, comprising: heating in the presence of a mild basic/nucleophilic esterification catalyst a monomer mixture comprising a hyperbranching monomer selected from the group consisting of: compounds having two COOH groups and one OH group, compounds having one COOH group and two OH groups, compounds having one COOH group and three OH groups, and compounds having three COOH groups and one OH group; to provide a hyperbranched polymer, wherein the mild basic/nucleophilic esterification catalyst is selected from carboxylates, alkoxides, oxides, and organometallics of tin, titanium, aluminum, antimony, manganese, zinc, and calcium and mixtures of these; the process comprising: melt-mixing: i) 0.05 to 10 weight percent of a hyperbranched polymer, ii) one or more thermoplastic polyesters; and iii) 1 to 50 weight percent of one or more fillers, to provide a thermoplastic composition, wherein: the weight percent of the hyperbranched polymer, of the one or more thermoplastic polyesters, and of the one or more fillers is based on the total weight of the thermoplastic composition; and the thermoplastic composition exhibits an increase in melt viscosity of less than 10 % as measured between 5 minutes and 32 minutes hold up time and according to ISO 11443 at 250 °C and at a shear rate of 1000 s -1. heating in the presence of a mild basic/nucleophilic esterification catalyst a monomer mixture comprising a hyperbranching monomer selected from the group consisting of: compounds having two COOH groups and one OH group, compounds having one COOH group and two OH groups, compounds having one COOH group and three OH groups, and compounds having three COOH groups and one OH group; compounds having two COOH groups and one OH group, compounds having one COOH group and two OH groups, compounds having one COOH group and three OH groups, and compounds having three COOH groups and one OH group; to provide a hyperbranched polymer, wherein the mild basic/nucleophilic esterification catalyst is selected from carboxylates, alkoxides, oxides, and organometallics of tin, titanium, aluminum, antimony, manganese, zinc, and calcium and mixtures of these; the process comprising: melt-mixing: i) 0.05 to 10 weight percent of a hyperbranched polymer, ii) one or more thermoplastic polyesters; and iii) 1 to 50 weight percent of one or more fillers, to provide a thermoplastic composition, wherein: the weight percent of the hyperbranched polymer, of the one or more thermoplastic polyesters, and of the one or more fillers is based on the total weight of the thermoplastic composition; and the thermoplastic composition exhibits an increase in melt viscosity of less than 10 % as measured between 5 minutes and 32 minutes hold up time and according to ISO 11443 at 250 °C and at a shear rate of 1000 s -1. i) 0.05 to 10 weight percent of a hyperbranched polymer, ii) one or more thermoplastic polyesters; and iii) 1 to 50 weight percent of one or more fillers, to provide a thermoplastic composition, wherein: the weight percent of the hyperbranched polymer, of the one or more thermoplastic polyesters, and of the one or more fillers is based on the total weight of the thermoplastic composition; and the thermoplastic composition exhibits an increase in melt viscosity of less than 10 % as measured between 5 minutes and 32 minutes hold up time and according to ISO 11443 at 250 °C and at a shear rate of 1000 s -1. the weight percent of the hyperbranched polymer, of the one or more thermoplastic polyesters, and of the one or more fillers is based on the total weight of the thermoplastic composition; and the thermoplastic composition exhibits an increase in melt viscosity of less than 10 % as measured between 5 minutes and 32 minutes hold up time and according to ISO 11443 at 250 °C and at a shear rate of 1000 s -1.