L. A. Utracki's research while affiliated with National Research Council Canada and other places

... Droplet/ matrix, fibrillar, lamellar, or co-continuous morphologies have been observed. Each of these morphologies depends on several factors such as composition, processing conditions (e.g., mixing time, temperature, shear, and elongational rate) or the nature of the polymers (e.g., interfacial tension, viscosity, and elasticity) (Utracki 2000). During the last decade, important theoretical and experimental advances on the rheology of liquid mixtures and polymer blends have been accomplished. ...

... In this regard, it is important to highlight that the flow and solid-state properties of polymer blends depend not only on the characteristics and relative percentage of the components, but also on the blend morphology and on the interfacial adhesion between the polymeric phases [11]. These features are, in turn, strongly affected by the compatibility degree of the blend. ...

... Complex viscoelastic behavior is expected when a multiphase polymer system is subjected to dynamic oscillatory shear, resulting from the interfacial tension differences between polymer phases (Kamal et al., 2014). The addition of a compatibilizer simultaneously reduces the interfacial tension at the interphases of the polymer and increases their adherence, thereby modifying the viscoelastic behavior of the compatibilized system (Ajji, 2014;Maris et al., 2018). ...

... A polymer blend is the combination of two or more polymers that have been blended to form a new material with different physical properties (Manias and Utracki 2014). The miscibility of the blend is dependent on thermodynamics. ...

... Across the tested range of blends, the dependence of viscosity on AM/AP ratios showed a negative deviation from the ad ditive viscosity (Fig. 4b). Such deviation is typical for systems con sisting of incompatible components, whereas positive deviation is pre dicted for compatible components (Utracki, 2016). Hence, one can assume that formylated AM and AP are incompatible in a formic acid Vasilyev, et al. ...

... In many different fields, homopolymers or copolymers alone may not always be able to satisfy all the requirements for practical usage. As a result, polymer blending, a physical combination of two or more polymers or copolymers without strong chemical bonds, became one of the workable solutions for achieving the desired properties of polymeric materials [7,24]. In addition to offering the desired properties, synthesizing new polymeric materials by blending polymers or copolymers is more economically feasible than creating new polymers or copolymers by chemical reactions. ...

... This is in agreement with the requirements of applications, such that the nanocomposites with these matrices can be of practical interest [7,8,[10][11][12][13][14]. The most common polymer blends are those of an immiscible nature that differ from the miscible ones through the interface nature of the interactions between the macromolecules. These interactions, in turn, depend on the chemical structure of the phases in contact, ultimately controlling the functional properties and the applications of the new compounds [15][16][17][18][19]. Nanocomposites with layered silicates are types of compounds in which the macromolecules are arranged between the silicate platelets or between the individual lamellae to generate stable compounds with thermo-mechanical properties of practical interest (e.g., Young's modulus, storage modulus, thermal stability, etc.) at low silicate concentrations [20][21][22][23]. ...

... Here, two types of melt mixers have been used that can be divided as batch mixing or continuous mixing, the batch mixing has been less effective as it could not carry the large capacities; however, it is good for laboratory processes. Moreover, the batch mixer can be called as internal mixer and that produced by Brabender or Haake, whereas continuous mixers produced by Banbury or Moriyama as dispersion mixers [83]. Apart from this, this method is useful to manufacture clay-polymer nanocomposites in which the polymer matrix can be either thermoplastic or elastomeric [84].Generally the polymer is melted with certain quantity of the intercalated clay using an extruder or Banbury, this process carried out in the presence of noble gases like argon, nitrogen or neon. ...

... To overcome these deficiencies, PP is often modified by combining it with fillers, fibers, or other polymers. Stiffness and heat deflection temperature are improved by the addition of reinforcements , while impact strength is increased by blending it with elastomers (Utracki, 1999). Recently, efficient impact modification of PP was achieved with synthetic poly(ethylene terephthalate) (PET) or poly(vinyl alcohol) (PVA) fibers (Várdai et al., 2021a). ...

... Later, the entire volume of empirical and theoretical knowledge in this field was summarized in handbooks 18,19 and reviews. 17,[20][21][22][23] Meanwhile, the synthesis of new polymers and nano-objects involving these materials in industrial practice contributed to the development in the interest in creating original compositions and studying their rheological properties and physical structure 24,25 and numerous special applications. Drug delivery is a good example of the latter. ...