Cure kinetics of bismaleimides as basis for polyimide-like inks for PolyJet™-3D-printing

Dispersion strategies of nanomaterials in polymeric inks for efficient 3D printing of soft and smart 3D structures: A systematic review

Nanoscience-often summarized as "the future is tiny"-highlights the work of researchers advancing nanotechnology through incremental innovations. The design and innovation of new nanomaterials are vital for the development of next-generation three-dimensional (3D) printed structures characterized by low cost, high speed, and versatile capabilities, delivering exceptional performance in advanced applications. The integration of nanofillers into polymeric-based inks for 3D printing heralds a new era in additive manufacturing, allowing for the creation of custom-designed 3D objects with enhanced multifunctionality. To optimize the use of nanomaterials in 3D printing, effective disaggregation techniques and strong interfacial adhesion between nanofillers and polymer matrices are essential. This review provides an overview of the application of various types of nanomaterials used in 3D printing, focusing on their functionalization principles, dispersion strategies, and colloidal stability, as well as the methodologies for aligning nanofillers within the 3D printing framework. It discusses dispersive methods, synergistic dispersion, and in-situ growth, which have yielded smart 3D-printed structures with unique functionality for specific applications. This review also focuses on nanomaterial alignment in 3D printing, detailing methods that enhance selective deposition and orientation of nanofillers within established and customized printing techniques. By emphasizing alignment strategies, we explore their impact on the performance of 3D-printed composites and highlight potential applications that benefit from ordered nanoparticles. Through these continuing efforts, this review shows that the design and development of the new class of nanomaterials are crucial to developing the next generation of smart 3D printed architectures with versatile abilities for advanced structures with exceptional performance.

Additive and Lithographic Manufacturing of Biomedical Scaffold Structures Using a Versatile Thiol-Ene Photocurable Resin

Additive and lithographic manufacturing technologies using photopolymerisation provide a powerful tool for fabricating multiscale structures, which is especially interesting for biomimetic scaffolds and biointerfaces. However, most resins are tailored to one particular fabrication technology, showing drawbacks for versatile use. Hence, we used a resin based on thiol-ene chemistry, leveraging its numerous advantages such as low oxygen inhibition, minimal shrinkage and high monomer conversion. The resin is tailored to applications in additive and lithographic technologies for future biofabrication where fast curing kinetics in the presence of oxygen are required, namely 3D inkjet printing, digital light processing and nanoimprint lithography. These technologies enable us to fabricate scaffolds over a span of six orders of magnitude with a maximum of 10 mm and a minimum of 150 nm in height, including bioinspired porous structures with controlled architecture, hole-patterned plates and micro/submicro patterned surfaces. Such versatile properties, combined with noncytotoxicity, degradability and the commercial availability of all the components render the resin as a prototyping material for tissue engineers.

Preparation and properties of bismaleimide resin blended with alkynyl-terminated modifiers

A kind of modified bismaleimide resin, with good processability, heat resistance, and impact strength was developed, using 4,4′-dipropargyloxydiphenyl ether (DPEDPE), N-(4-propargyloxyphenyl)maleimide (4-PPM), and 3-ethynylphenyl maleimide (3-EPM) as modifiers. The DPEDPE, 4-PPM, and 3-EPM were synthesized and characterized by Fourier transform infrared spectroscopy (FTIR) and 1H-nuclear magnetic resonance (1H NMR), and used to modify the N,N′-(4,4′-diphenylmethane)bismaleimide (BDM)/2,2′-diallyl bisphenol A (DABPA) resin system (BD) to obtain the different blend resin systems of DPEDPE-modified BD (BDD), 4-PPM-modified BD (BDP), and 3-EPM-modified BD (BDE). The curing temperature of BD resin increases with increase of the alkynyl-terminated modifier content. The processability of BD resin was improved with addition of the propargyloxy-terminated compounds. The temperature of 5% weight loss, residual yield at 800°C and glass transition temperature of the cured BD resin increase with increase of the alkynyl-terminated modifier content and can reach 443°C, 46.7% and higher than 380°C. The tensile strength of the cured BD resin decreases with increase of alkynyl-terminated modifier content. The impact strength of the cured BD resin increases with increase of the propargyloxy-terminated compound content and can increase by 65%. The tensile strength, elastic modulus, and impact strength of the cured BD resin blended with DPEDPE can be 73.7 MPa, 4.1 GPa, and 19.6 kJ m−2, respectively. Moreover, the cured BD resin blended with DPEDPE has good water absorption resistance.