Polymorphism in polyamide 66/clay nanocomposites

Bio-polyamides based on renewable raw materials

“…Jasińska et al [24] found similar results for polyamide 4.10 and its copolymers, and they described the peak at 2h = 23°as characteristic of the c-crystalline phase. On the contrary, for PA 6.6, Liu and coworkers assign this reflection as one of the distinctive features of the a-phase in polyamides and state that polyamides present usually more stable a-phase rather than c ones in XRD [20]. In the c-form phase of the polyamide, hydrogen bonds take position between parallel macrochains, while in a-form the antiparallel arrangement is present, and the latter is more stable because of shorter hydrogen bonds [35].…”

“…The former effect is related to the formation of different crystal structures, i.e., the planar aand the pleated c-structures, while the latter is an effect of crystal phase transformation prior to melting [20].…”

Vermiculite: Structural Properties and Examples of the Use

“…The methods used for the preparation of clay-polymer nanocomposites, include solvent intercalation, in situ polymerization, and melt-compounding [98][99][100][101][102]. Both solvent intercalation and in situ polymerization allow polymer chains to enter into the galleries of silicate clays.…”

Nylon 66/clay nanocomposite structure development in a twin screw extruder

“…PA66 is an important engineering plastic with high performance and the addition of clay is thought to strengthen the polymer matrix and create new materials with even better properties. There have been several studies on melt processing of nylon 66 (PA66) and clay nanocomposites [including [12][13][14][15][16][17][18][19][20][21][22]. However, like many other polymer/clay systems, studies on PA66/clay nanocomposites have focused on the final composite's morphological [12,13,15,16,[19][20], thermal [12-14, 16, 18, 19, 21, 22], and mechanical properties [12][13][14][15][16][17][18].…”