PMMA/SAN and SAN/PBT nanoblends obtained by blending extrusion using thermodynamics and microrheology basis

Abstract

Abstract. Styrene-Acrylonitrile (SAN) copolymer has been blended to poly(methyl methacrylate) (PMMA) and to poly(butylene terephthalate) (PBT) to obtain polymer nanoblends based on thermodynamics and microrheological aspects. PMMA/SAN and SAN/PBT blends show miscibility windows for a specific range of acrylonitrile (AN) content in the SAN copolymer. The phase diagram for both blends has been calculated using the interaction energy density parameter B as function of AN content in the SAN. A critical interaction energy density parameter, B crit , was also calculated to find the miscibility window for both SAN blends. For some of the used SAN in the blends it was possible to obtain nanoblends as the AN content would allow B values close to the B crit . For immiscible PMMA/SAN and SAN/PBT blends the disperse particle size was predicted using suitable equations and it was observed by transmission electron microscopy (TEM). Acrylic copolymers were used as compatibilizer to modify the interfacial tension and reduce the disperse phase dimensions. The compatibilizer has shown strong effect by reducing the interfacial tension and by preventing the coalescence effect. The compatibilized blends have shown disperse particle size within the nanoscale.

Development of biodegradable PLA/PBT nanoblends

“…Figure 6 shows the phase morphology of the blends after injection molding of the specimens, analyzed in both scanning and transmission electron microscopy. 9,10,27,28 The role of the compatibilizer in the blend is to reduce interfacial tension and aid in dispersion and stabilization of the system by preventing the coalescence of the particles. Studies show that the morphology of immiscible blends is influenced by the composition of the blends, viscosity ratio, flow type, and capillary number, which is defined as the ratio between the shear stress, imposed by the flow field on the particles, which tend to deform (break), and the interfacial tension that opposes this deformation.…”

“…1,3 Blending of PLA with an immiscible component has been reported in order to obtain improved toughness and expand PLA use and applications. [9][10][11][12][13][14] However, some authors consider that nanostructures are characterized by particle size on the submicron scale, 10,15,16 where the dispersed phase assumes dimensions comparable to the size of the molecules that make up the polymer blend systems. The phase morphology of immiscible blends depends on intrinsic parameters of the materials such as viscosity ratio, elasticity ratio, interfacial tension, composition of the blends, and processing conditions, such as temperature, time, mixture intensity/shear rate, and nature of the flow.…”

Rheological Modeling of Polymeric Melts in Extruders upon Two-Dimensional Shear Flow

“…Extrusion has been the subject of many studies, focusing on the mathematicalmodelling of the process, innovative technological developments, new applications and optimization (Baird and Collias, 1995;Srinivasa et al, 2004;Costa et al, 2014;Basi et al, 2005;Hongyu et al, 2007;Gupta et al, 2014).…”

Development of phase morphology in immiscible poly(styrene‐co‐acrylonitrile)/poly(butylene terephthalate) nanoblends: Mechanical properties and effect of the compatibilizer

“…The singular properties of a material can be obtained by the preparation of particular immiscible polymer blends when the particle dimensions of the dispersed phase are on a nanometric scale. Because of its reduced dimensions, such a polymer blend is called a nanoblend . The significant reduction in the size of the dispersed‐phase particles significantly increases the interfacial contact, and this can lead to improvements in the mechanical, electronic, and optical properties of the blend.…”

“…The significant reduction in the size of the dispersed‐phase particles significantly increases the interfacial contact, and this can lead to improvements in the mechanical, electronic, and optical properties of the blend. Most studies have considered nanoblends to be mixtures in which the range of the dispersed phase in a matrix is usually less than 100 nm . However, according to some authors, nanostructures are characterized by particle sizes in the submicrometer range, where the dispersed phase assumes dimensions comparable to the size of the molecules that are part of those polymer blends .…”