Polyamide 6 and polyamide 66 blends with functionalized polyolefins: Effect of phenomenal increase in viscosity and melt strength of polyamide 66‐based materials

Abstract

The effect of adding blends of linear low‐density polyethylene (LLDPE) and ethylene‐octene copolymer (EOC) functionalized by grafting (in the course of reactive extrusion) of trans‐ethylene‐1,2‐dicarboxylic acid (TEDA) onto polyamide 6 (PA6) and polyamide 66 (PA66) on rheological and elastic properties of their melts, structural morphology, and mechanical properties has been studied. It is shown that PA66/functionalized polyolefins (fPO) blends are characterized by more significant changes in the characteristics being analyzed as compared to PA6/fPO blends. A phenomenally sharp increase (by more than two decimal orders of magnitudes) in the melt viscosity of PA66/fPO blend as compared to the initial PA66 was established. At the same time, the melt strength may increase more than 50‐fold. The degree of TEDA grafting (β) onto PO macromolecules is the most important parameter determining the level of the values of property indices, as well as the structural features of PA/fPO blends. Only when particular β values (varying in a relatively narrow range) are reached, a quasi‐homogeneous morphology is formed in PA/fPO blends and their deformation capacity as well as the impact strength of materials increase dramatically. The observed effects are caused by the influence of TEDA grafting on interphase interactions in PA/fPO and PA66/fPO blends.

Effects of process conditions on tensile strength and crystallinity of polymeric parts fabricated using ultrasonic vibration‐assisted injection molding

“…Second, compared to other polymer melts, PA66 has a lower viscosity and better flowability. [30][31][32] Thus, jet flow can be observed during PA66 injection molding, [33,34] making it easy to form microscale air bubbles in the fabricated specimens as shown in the inset of Figure 3D. These microscale air bubbles further weaken the mechanical properties of the specimens.…”

Electrocatalytic conversion of waste polyamide‐66 hydrolysates into high‐added‐value adiponitrile and hydrogen fuel

“…Unlike PET, which can be readily hydrolyzed by base or hydrolase, 14 PA‐66 is resistant to light, abrasion, and strongly basic conditions. However, the amide bond of PA‐66 can be readily degraded into monomers under mild conditions with hydrolyzed acid 15–17 . In view of this, as shown in Figure 1A, the integrated system for PA‐66 upcycling contained several reaction steps: (i) H 2 SO 4 ‐catalyzed PA‐66 (Equation 1), (ii) hydrolysis product separation, (iii) KOH‐assisted filtered hydrolysate (Equation 2), and (iv) electroreforming of KOH‐assisted PA‐66 hydrolysate (Equation 3), including hexamethylenediamine (HMD) oxidation (Equation 4) and paired hydrogen evolution reaction (HER) (Equation 5).…”

The Cellular Structure and Mechanical Properties of Polypropylene/Nano-CaCO3/Ethylene-propylene-diene-monomer Composites Prepared by an In-Mold-Decoration/Microcellular-Injection-Molding Process

“…As the EPDM content increased from 0 wt% to 20 wt%, the offset angle gradually decreased, the ratio of length-diameter increased, and the cells tended to be flat. When the viscosity increased, the migration resistance of the melt flow also increased, resulting in greater deformation of the bubbles and an increase in the length-diameter ratio [26,27]. Table 3 shows the microcellular structure parallel to the melt-flow direction in th core layer and the transition layer.…”