The Influence of Blend Morphology (Co‐Continuous or Sub‐Micrometer Droplets Dispersions) on the Nucleation and Crystallization Kinetics of Double Crystalline Polyethylene/Polyamide Blends Prepared by Reactive Extrusion

Abstract

Reactive blending of functionalized polyethylenes (PE) and polyamides (PA) is performed by carefully choosing extrusion conditions and polymeric materials in order to obtain two types of stable morphologies. The first blend type yields a co‐continuous morphology and the second type a dispersion of sub‐micron droplets of the PA phase in a PE matrix. The crystallization kinetics of the PA change from a sigmoidal classical type (for the co‐continuous blend) to first‐order kinetics in the case of the sub‐micron PA droplets. The results demonstrate an intimate relationship between blend morphology and nucleation and crystallization kinetics of the blend components. magnified image

Epoxy/poly(ɛ‐caprolactone) nanocomposites: Effect of transformations of structure on crystallization

“…Obviously, during cooling, the crystallization in the sample with small PCL inclusions in the epoxy matrix starts as high as at about 0°C and then runs slowly to reach the maximum rate at about −42°C. It thus shows some kind of the fractionated crystallization …”

“…The overall crystallization rate evaluated from the low‐temperature exotherm b is higher than that from exotherm a . Apparently, once the system overcomes a potential barrier where greater undercooling is necessary as a driving force, the crystallization proceeds at a higher rate. Moreover, in the epoxy/PCL samples with the co‐continuous morphology crystallizing in two steps, the overall rate of crystallization is much higher in the second step in the low‐temperature region (exotherm b ) than in the high‐temperature region (exotherm a ).…”

“…The effect of morphological type on crystallization was demonstrated by comparison of the co‐continuous and matrix/droplets structures formed either by reactive‐compatibilization in polyethylene/polyamide blends or by annealing the electrospun blend of polysulfone/poly(vinylidene fluoride) . With co‐continuous structure, heterogeneous nucleation similar to the bulk sample occurred, whereas fractionated/homogeneous crystallization was found for isolated small droplets.…”

Self-Nucleation of Crystalline Phases Within Homopolymers, Polymer Blends, Copolymers, and Nanocomposites

“…Coincident and fractionated crystallization phenomena are frequently observed in blends and copolymers, and SN can be employed to investigate the origin of the crystallization process [3,8,[87][88][89][90][91][92][93][94][95][96][97][98][99][100]. The work performed by Morales et al [93] has been chosen as an example of the application of SN to a polymer blend.…”

Mechanical properties, morphology and thermal conductivity of polyamide composites filled with graphene nanoplatelets, Al2O3and graphite

“…1,2 However, the application of neat PA6 or PA66, two kinds of nylon, has been limited to some special fields due to its relatively low thermal conductivity. Therefore, PA is mostly compounded with other polymers [3][4][5] or rigid particles [6][7][8][9][10][11][12][13] to overcome these limitations. Graphene is an atomically thick, two-dimensional (2D) sheet composed of sp 2 carbon atoms arranged in a honeycomb structure.…”