Boronic Ester-Modified Resins: Dual-Function in Micro-Additive Manufacturing and Ceramization

Abstract

Herein, the synthesis of a novel borate ester-functionalized monomer was reported, designated mBBDA, through an esterification reaction between 1,3-benzenediboronic acid (mBBA) and glycidyl methacrylate (GMA). This monomer was subsequently formulated with pentaerythritol triacrylate (PETA) to produce a series of photocurable resins, denoted as P-mBMAx, with mBBDA content systematically varied from 0 to 100 wt%. P-mBMAx resins served as photoresists for high-resolution two-photon polymerization (TPP) lithography. Mechanical characterization revealed that the resin incorporating 60 wt% mBBDA (P-mBMA6) demonstrated a 12.5% enhancement in impact strength (5.4 kJ•m -²) relative to the unmodified PETA benchmark, while also maintaining a high Young's modulus of 6.61 GPa and a hardness of 0.395 GPa.Utilizing a 780 nm femtosecond laser, TPP fabrication with these resins achieved sub-micron feature resolution even at remarkably high scanning speeds of up to 100,000 μm•s -¹, thereby enabling rapid prototyping. Furthermore, microarchitectures fabricated via TPP using the P-mBMAx photoresists were successfully converted into porous boron carbide (B₄C) ceramics through a subsequent sintering process. The formation of B₄C was unequivocally confirmed by X-ray diffraction (XRD) analysis. Remarkably, the sintered ceramics retained their original three-dimensional architectures with high structural fidelity. This study establishes that mBBDA-modified resins provide a versatile platform, offering tunable mechanical properties, inherent self-healing capability, and dual functionality for both cross-scale additive micronanofabrication and the preparation of high-fidelity, porous boron carbide ceramics.