| Summary: | Polymers are essential components of melt extruded products. The objective of the present study was to generate physicochemical data of polyvinylpyrrolidone-based polymers and copolymers that are used in hot melt extrusion (HME). This study focused on investigating the importance of viscoelasticity for predicting HME processing conditions. Powder X-ray diffraction (XRD) patterns of polymers were recorded to determine the physical nature of the polymers. Differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA) were carried out to determine their glass transition temperature (Tg) and weight loss due to degradation (Td), respectively. Rheological studies were conducted to quantitate storage modulus (G´), loss modulus (G˝), tan δ and complex viscosity (η) of the polymers at various temperatures. Powder XRD analyses showed that all polymers were amorphous in nature, with distinct single or dual halos. DSC showed that the amorphous polymers had single Tg values. The conversion of the polymers, from solid to liquid forms, with increasing temperature was established by the tan δ = 1 values. The overall complex viscosity for all polymers decreased with increasing temperature. The
complex viscosity of one of the polymers, Soluplus®, was correlated using torque analysis through HME to establish an extrudable temperature range. The results are expected to assist in the selection of
polyvinylpyrrolidone-based polymers for HME. Once the appropriate polymers are selected, further studies may be carried out using drugs, plasticizers and, so on, to optimize processing conditions.
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