Preparation Methods, Performance Improvement Strategies, and Typical Applications of Polyamide Foams

Abstract

Polyamide (PA) foams have been widely applied in many areas due to their outstanding properties and currently are receiving more extensive attention from the fundamental research and materials communities. However, poor melt strength and low matrix modulus seriously affect the preparation of high-performance PA foams and hinder their commercialization process. To overcome the limitations, a lot of efforts have been devoted to the research subject. In spite of the striking progress made dealing with PA foams, there has been no review to summarize the studies yet. This review begins with the consideration of the foaming process of PA and commonly used methods for PA foaming. Special emphasis is placed on effective means to enhance the performance of PA foams. Then, the typical applications of PA foams are presented, such as flame retardant, oil spill cleaning, electromagnetic shielding, and tissue engineering. Finally, the future perspective of PA foams will be outlined as well as the recommended future research directions about them.

Intercalation Engineering of 2D Materials at Macroscale for Smart Human–Machine Interface and Double‐Layer to Faradaic Charge Storage for Ions Separation

“…[ 23 ] Alternatively, foaming materials are classified either as soft foam or rigid foam or bead foams, batch foams, and extrusion foams. [ 28 ] The presence of excessive oxygen‐containing functional groups and the hydrophilic nature of graphene oxide are responsible to form stable aqueous colloids to facilitate the assembly of macroscopic structures. [ 29 ] However, pore size and diameter can be controlled by the concentration of graphene oxide which results in micro and macroscopic structure.…”

“…Many polymers and polymer‐based templates are reported for porous architecture such as polyamide, [ 28 ] polydimethylsiloxane (PDMS), [ 59 ] polypyrrole (ppy), [ 60 ] thermoplastic polyurethane (TPU), [ 61 ] poly(3,4‐ethylene dioxythiophene), [ 62 ] poly(styrene sulphonate), [ 63 ] poly(ethylene terephthalate), [ 64 ] polyacrylic acid, [ 65 ] and polyvinyl alcohol. [ 66 ] This apart poly‐amic acid and poly(amic ester) are also explored to develop polyimide graphene foam composites.…”

Effect of viscosity on foaming behavior and surface quality of foamed Polyamide 6

“…Its simple production process and low energy consumption during processing make it a popular choice in industries that require lightweight and high-strength materials, such as the automobile, electronic and electrical communication, film packaging, aerospace, and rail transit industries. [8][9][10] The low melt strength of PA6 results in an inability to maintain cell morphology during cell growth. This can lead to further cell growth, thinning or rupture of cell walls, and ultimately, the merging of cells.…”

“…PA6 is a versatile material that can be easily molded into complex structural parts. Its simple production process and low energy consumption during processing make it a popular choice in industries that require lightweight and high‐strength materials, such as the automobile, electronic and electrical communication, film packaging, aerospace, and rail transit industries 8–10 . The low melt strength of PA6 results in an inability to maintain cell morphology during cell growth.…”

Multifunctional Lightweight Guanidine Phosphate/Poly(Vinyl Alcohol) Melamine-Based Hybrid Foam for Superior Thermal Insulation and Flame Retardancy

“…The conventional organic thermal insulation materials are made from polystyrene foams (0.026–0.040 W·m –1 ·K –1 ), polyurethane foams (0.02–0.03 W·m –1 ·K –1 ), , phenolic foams (0.03–0.04 W·m –1 ·K –1 ), , and so on, possessing the characteristics of lightweight and low thermal conductivity. Unfortunately, these materials are flammable and release toxic gases during combustion, limiting their widespread application in the thermal insulation field.…”