Novel Guar Gum (GG) and polyethylene glycol (PEG) polymer blends with rosin glycerol ester (RE) nanoparticle was synthesized under ultrasonic irradiation at different composition ratios (1:1, 1:2, 1:4, 2:1, and 4:1). The intrinsic viscosities of the nanoparticles were investigated using ultrasound irradiation to determine the miscibility of the blends in solution as affected by salt, sonication time, temperature, and pH. The intrinsic viscosities of the nanosystems were compared with five different models, including Huggins, Kraemer, Tanglertpaibul-Rao, Higiro, and Rao. The Tanglertpaibul-Rao was the best model and the intrinsic viscosities of 138,27, 142,94 and 163,29 dl/g were reported for GG-PEG/RE (1:1,1:2,1:4), respectively. The viscosity results reveal that the blend containing 1:2 (GG-PEG/RE) was an optimum miscible blend. The miscibility behaviour of the polymeric nanoparticles was investigated using the voluminosity (VE), shape factor (u), creaming index (CI) parameter, and the Krigbaum and Wall parameter (Delta b), which account for the intermolecular interactions. When compared to the intrinsic viscosity results of the nanoparticles, the miscibility-improving effect of sub-300 nm GG-PEG/RE nanoparticles is clearly proven due to the ultrasonic effect. Scanning transmission electron microscopy (STEM) and Fourier transformed infrared (FTIR) spectroscopy were used for characterization of the polymeric nanoparticles. (C) 2019 Elsevier B.V. All rights reserved.