Polyblends are provided which comprise (a) a major amount of a linear or branched matrix polymer comprising a polyester having a number average molecular weight of at least 2000 or a vinyl polymer having a number average molecular weight of at least 3000 and (b) a minor amount of a block copolymer of AB or ABA type wherein A is a homopolymer block which is compatible with the matrix polymer and B is a homopolymer block which is incompatible with the matrix polymer, the blend having a fusing temperature of not more than about 250.degree. C., a melt viscosity of from about 4.times.10.sup.2 to 5.times.10.sup.4 poise as measured on a Rheometrics Dynamic Analyzer at 150.degree. C. and a frequency of 1 rad/sec and a melt elasticity of from about 1.5.times.10.sup.2 to 4.times.10.sup.4 dynes/cm.sup.2.The polyblends are useful in the preparation of electrostatographic toner compositions used in electrographic processes.