Novel poly(aryl ether nitrile ketone) foams and the influence of copolymer structure on the foaming result

Microporous polyarylate membranes based on 3D phenolphthalein for molecular sieving

Thin-film composite (TFC) membranes have gradually replaced some traditional technologies in the extraction, separation, and concentration of high value-added pharmaceutical ingredients due to their controllable microstructure. Nevertheless, devising solvent-stable, scalable TFC membranes with high permeance and efficient molecule selectivity is urgently needed to improve the separation efficiency in the separation process. Here, we propose phenolphthalein, a commercial acid-base indicator, as an economical monomer for optimizing the micropore structure of selective layers with thickness down to 30 nanometers formed by in situ interfacial reactions. Molecular dynamics simulations indicate that the polyarylate membranes prepared using three-dimensional phenolphthalein monomers exhibit tunable microporosity and higher pore interconnectivity. Moreover, the TFC membranes show a high methanol permeance (9.9 ± 0.1 liters per square meter per hour per bar) and small molecular weight cutoff (≈289 daltons) for organic micropollutants in organic solvent systems. The polyarylate membranes exhibit higher mechanical strength (2.4 versus 0.8 gigapascals) compared to the traditional polyamide membrane.

Synthesis and Properties of Semicrystalline Poly(ether nitrile ketone) Copolymers

As a high-performance engineering plastic, polyarylene ether nitrile (PEN) is widely used in many fields. The presence of cyano groups of PEN ensures its good adhesion to other substrates, but the inherent low crystallinity of PEN limits its application. In this work, the poly(aryl ether ketone) segment was introduced into PEN via copolymerization using both 2,6-Dichlorobenzonitrile and 4,4'-Difluorobenzophenone as the starting reagents to prepare poly (ether nitrile ketone) (BP-PENK). The effect of composition and thermal treatment on the crystallization behavior and properties of poly (ether nitrile ketone) were systematically studied. It was found that when the content of DFBP is 30%, the copolymer BP-PENK30 had the best mechanical properties, with a tensile strength of 109.9 MPa and an elongation at a break value of 45.2%. After thermal treatment at 280 °C for 3 h, BP-PENK30 had the highest crystallinity with a melting point of 306.71 °C, a melting enthalpy of 5.02 J/g, and crystallinity of 11.83%. Moreover, with the increase in crystallinity, the dielectric constant and energy density increased after thermal treatment. Therefore, the introduction of poly(aryl ether ketone) chain segments and thermal treatment can effectively improve the crystallization and the comprehensive properties of PEN.

Preparation of Amorphous Poly(aryl ether nitrile ketone) and Its Composites with Nano Hydroxyapatite for 3D Artificial Bone Printing

PEEK had been used to fabricate artificial bones by 3D printing widely, but it expressed unsatisfactory interlayer performance of 3D printing and weak compatibility with nano hydroxyapatite(nHA) due to the limits of molecular structures. Here an amorphous poly(aryl ether ketone) for 3D bone printing, PEK-CN, was designed and synthesized via nucleophilic substitution from 4,4'-difluorobenzophenone, phenolphthalein and 2,6-dichlorobenzonitrile, which possessed much stronger interlayer strength due to van der Waals force between polar groups(-CNs). Specifically, the stronger interlayer strength resulted in lower porosity(3% with 100% infill rate) and more comparable mechanical properties(the maximum tensile strength was ∼110 MPa) to cortical bone. Importantly, PEK-CN had passed in vitro cytotoxicity testing and samples of human mandible and maxillary bones based on PEK-CN were printed by fused deposition modeling(FDM) successfully. Moreover, PEK-CN/nHA composites were obtained to enhance bioactivity of resin, and PEK-CN without limits of crystal lattices expressed excellent compatibility with nano hydroxyapatite. Our work provided a high performance resin for 3D bone printing, which would bring better solutions for artificial bone materials.