Effects of Hard Segment Length on the Mechanical Properties of Poly(PA11-co-DA) Periodic Copolymers

Abstract

Polyamide 11 (PA11) is a semicrystalline polymer with excellent mechanical property. However, the use of PA11 with high crystallinity as an engineering plastic is limited because of its low impact resistance. In this work, a series of sustainable poly(PA11-co-DA) copolymers (PAx-p-DAy) were synthesized via polycondensation from vegetable oil-based dimer acid (DA) and diamine terminated polyamide 11 (ATPA11-x). The molecular structure of PAx-p-DAy was characterized by 1 H NMR, 13 C NMR, FT-IR, XRD, and viscometry. The mechanical properties of the periodic copolymers depended on the bulky DA content and the chain length of ATPA11-x. As the content of bulky DA increased and the chain length of ATPA11-x decreased, the degree of crystallinity of the PAx-p-DAy copolymers decreased, but the tensile strength, elongation, and tensile toughness increased. In addition, the low-temperature and room-temperature impact toughness of the copolymer was also remarkably improved. These thermoplastic polyamides have the potential to be widely applied.

Novel Thermoplastic Composites Strengthened with Carbon Fiber-Reinforced Epoxy Composite Waste Rods: Development and Characterization

“…Even though PA6 and PA66 account for almost 90% of the polyamide market, PA11 and PA12 also have a significant market share. PA11 is a bio-based polyamide obtained from castor oil, a renewable source, thus resulting in a reduced carbon footprint compared to PA12 [ 13 , 14 ]. Apart from being bio-based, PA11 is experiencing a sharp increase in demand due to several of its features, including its low moisture absorption and high impact, fatigue, chemical, and aging resistance [ 15 ].…”

Semicrystalline-Glassy Multiblock Copolymers via Mechanochemical Synthesis toward Tough Poly(lactide)

“…Because the PA11 chains in the multiblocks were oriented in the same direction during the stretch, the reinforced crystallinity could induce the PLA toughening effect. It was proved that the (PA11–PLA) n was elongated beyond the increased yield stress, up to 63 MPa, and long lasting ductility, including strain hardening (Figure c–f) . Also, the intensity of another reflection around 10.8–18.5° gradually increased as f PLA increased from 0.5 to 0.8.…”

“…It was proved that the (PA11−PLA) n was elongated beyond the increased yield stress, up to 63 MPa, and long lasting ductility, including strain hardening (Figure 6c− f). 96 Also, the intensity of another reflection around 10.8− 18.5°gradually increased as f PLA increased from 0.5 to 0.8. The increased PLA amorphous region in the multiblocks might strengthen the mechanical performance, including toughening with strain hardening; however, this will require further studies.…”

Vegetable Oil-Derived Polyamide Multiblock Copolymers toward Chemically Recyclable Pressure-Sensitive Adhesives

“…Most of the methods for modifying PA11 involve blending PA11 with other polymers. , The blending is simple in the processing, but it may cause compatibility problems due to the difference in polarity of each polymer being blended. − So, the block copolymer linked by chemical bonds can solve the problem of compatibility. There are few studies on PA11-based copolymers. − Kucera et al synthesized a multiblock copolymer with PA11 and polyisobutylene and Gardella et al synthesized a diblock copolymer with PA11 and poly­(lactic acid) . Arkema (Pebax, France) synthesized a PA11-based TPE linked by an ester linkage between two prepolymers, a carboxylic acid-terminated PA11 (hard segment) and a hydroxyl-terminated poly­(oxyalkylene) glycol (soft segment) .…”