ACS Applied Polymer Materials最新文献

In this study, we designed highly sensitive photoresist resins, JN05 and BN05, having both a photosensitive DNQ unit as a nonchemical amplification mode and the photo acid-cleavable groups like the ethyl vinyl ether (EVE) and diethyl decarbonate (BOC) protection groups as a chemical amplification mode. Resists with these dual-sensitive chemical reaction modes will undergo photolysis in the DNQ unit after exposure and further the acid-catalyzed deprotection reactions of the EVE and BOC groups after post-exposure bake. This dual-sensitized photolysis of the photoresist occurs at mild reaction conditions, enabling synergistic modifications by multiple functional groups. Upon exposure to doses of 150 mJ/cm² and 90 mJ/cm², respectively, JN05 and BN05 produced clear positive tone patterns with a line width of 1.0 μm (L/S = 1:1). Compared with the Novolac/DNQ system itself, the JN05 and BN05 photoresists combined the benefits of CA photoresists, nonchemically amplified solubility properties, and the multifunctional characteristics achieved by the DNQ system and CA comodification. The present work provides an approach for the improvement of photoresist sensitivity and resolution in the UV resist system.

Dual-curing photosensitive resins have been widely used in digital light processing (DLP) printing to obtain outstanding mechanical properties. Although considerable research efforts and advancements have been made in thermosetting resins, numerous challenges still remain in understanding the influence of the photopolymerization network on the curing of thermosetting resins and the synergistic effect of the photothermal polymerization network. In this study, a variety of dual-cure photosensitive resins were synthesized by blending diverse acrylate oligomers or acrylate monomers with acryl-functional benzoxazine. Through an exploration of the photo and thermal polymerization behaviors of the dual-cure resins, it was determined that the curing degree of benzoxazine increased as the cross-link density of the photopolymerized network decreased. Concurrently, the mechanical strength and heat resistance of the dual-cured resins were further enhanced with the incorporation of highly polar or rigid acrylic components. The glass transition temperature (T_g) of P₈B₂-HE₁₀-220 reached 250 °C. Moreover, the 5% weight loss temperature (T_d5) of P₈B₂-AC₁₀-220 and P₈B₂-HE₁₀-220 reached 311 and 296 °C, respectively. Upon dual-curing, a hybrid polymer network (HPN) was formed by combining the photopolymerized networks and the polybenzoxazine networks, which further improved the mechanical strength of the dual-cured photosensitive resins. The introduction of highly polar 2-hydroxyethyl acrylate (HEAA) enabled the tensile strength of P₈B₂-HE₁₀-220 to reach 146.62 MPa, which represents a 13.94% increase compared to that of P₈B₂-220. Meanwhile, the Young’s modulus of P₈B₂-DC₁₀-220 modified with the highly rigid dicyclopentanyl acrylate (DCPA) reached 7.19 GPa, signifying a 17.29% elevation relative to that of P₈B₂-220. These findings will propel the formulation design based on photothermal dual-curing reactions and offer solutions for the efficient manufacturing of a diverse range of high-performance materials with stringent requirements.

Transparent optical polymers are an emerging class of materials that are finding applications in lenses, prisms, and waveguides. For lens applications, polymers with a high refractive index and a low Abbe value are required. Herein, we present UV-curable compositions with optical properties competitive with those of industry-standard thermoplastics. We designed and synthesized a monomer (NTBA) consisting of a naphthyl ring and a benzyl acrylate unit connected by a sulfur atom. Using NTBA as an additive reduced the Abbe value of the cured product, resulting in a polymer with a refractive index of 1.628 and an Abbe number of 24.5, exhibiting excellent stability against heat and humidity. Further optimization of monomer compositions yielded a polymer with a refractive index of 1.673 and an Abbe number of 20.4. Our material design strategy enables next-generation fabrication processes for optical components, including wafer-level processes.

Achieving superior ionic selectivity in membranes is vital for enhancing the performance of vanadium redox flow batteries (VRFBs). In this study, we synthesize a series of ether-free poly(arylene methylimidazole) copolymers (P(MeIm-co-X)) enriched with methylimidazole groups. These copolymers are prepared via a straightforward superacid-catalyzed polymerization of 1-methyl-2-imidazolecarboxaldehyde with five distinct aromatic monomers: biphenyl, fluorene, 1,2-diphenylethane, diphenyl sulfide, and p-terphenyl (used as a reference). Our objective is to investigate how variations in the polymer backbone’s chemical structure affect membrane properties relevant to VRFB applications. The incorporated basic methylimidazole groups facilitate ion transport through hydrogen bonding, while modifications in the aromatic monomer structures adjust the polymer microstructure to optimize area resistance and ionic selectivity. Among the synthesized membranes, the fluorene-based P(MeIm-co-Flu) exhibits the most outstanding performance, displaying excellent chemical stability, high tensile strength (22.4 MPa), and low area resistance (0.32 Ω cm²). When evaluated in VRFBs at a current density of 100 mA cm^–2, the P(MeIm-co-Flu) membrane achieves an energy efficiency (EE) of 85.7%, surpassing that of Nafion 115 (76.5%). Additionally, this membrane demonstrates exceptional capacity retention over 570 cycles at 100 mA cm^–2, maintaining Coulombic efficiencies above 99%, with energy efficiencies decreasing slightly from 85.4% to 80.9%. Therefore, this work presents a high-performance, easily synthesized, and cost-effective P(MeIm-co-Flu) membrane for potential application in VRFBs.

Amidst the escalating energy demand, the development of nonfossil, biorenewable, and sustainable resources becomes particularly pressing and crucial. In this research, a biomass polyurethane acrylate (JPUA) derived from jatropha oil (JO) was successfully synthesized and a JPUA_x composite coating was successfully fabricated by doping monolayer graphene (LG) nanoparticles. After rapid UV curing, JPUA_x has twice the mechanical properties of JPUA coatings, with tensile strengths of up to 15.8 MPa, a significant advantage over other coatings of this type, as well as excellent corrosion resistance. The coating was immersed in strong acid, alkali, and high-salt solutions for 30 days with negligible changes in quality or surface morphology. Based on the outstanding corrosion resistance of JPUA_x, a composite fluorescent coating of JPUA_x with biobased properties was prepared by loading fluorescent powders of different colors, and a dual anti-counterfeiting system was constructed by combining the coating and Morse code. Fluorescent stickers have also been developed to facilitate long-term encryption in daily life. Overall, this work not only expands the synthesis strategy of biomass polymers derived from nonfossil resources but also provides an additional way for multifunctional composite fluorescent coatings in anti-counterfeiting and information encryption applications.

We designed and synthesized pyrrolidinium-based polyurethane ionenes. These ionenes were synthesized using dihydroxyundecyl pyrrolidinium ionic liquid monomers with various anions (Br^–, PF₆^–, or Tf₂N^–), along with a poly(ethylene glycol) (1000 or 4000) comonomer and one of three chain extenders: methylene diphenyl 4,4′-diisocyanate (MDI), tolylene-2,4-diisocyanate (TDI), and 4,4′-methylenebis(cyclohexyl isocyanate) (HMDI). To investigate the structure–property relationship, a comprehensive study of the thermal properties and ion conduction of the synthesized ionenes was conducted. The synthesized ionenes mostly exhibit an amorphous morphology; however, only ionenes containing PEG-4000 block show semicrystalline features. The copolymer ionenes containing PF₆^– anions exhibit higher glass transition temperatures (T_g) compared to those with other anions due to hydrogen bonding with the N–H groups (urethane). Also, the pyrrolidinium/PEG-4000 copolymer ionene with PF₆^– shows a higher degree of crystallinity. Among the synthesized ionenes, the pyrrolidinium-Tf₂N polyurethane copolymer with PEG-1000 exhibits the lowest T_g (−21 °C) and the highest ionic conductivity of 1.04 mS/cm (at 70 °C). These findings suggest that pyrrolidinium-based polyurethane ionenes have potential applications in ion-conductive materials, particularly in energy storage devices such as energy storage (e.g., batteries) and conversion devices (e.g., solar cells).

Organic semiconductor polymers have garnered significant attention within the realm of photocatalytic hydrogen generation. Researchers have designed numerous schemes to enhance the efficiency of hydrogen generation by leveraging the tunable properties of their main chains. The donor–acceptor (D–A) strategy is a recognized approach for tuning the photoelectric properties of polymer semiconductors; however, its application within organic photocatalytic hydrogen generation demands thorough investigation. Here, we use the polyfluorene derivatives to study the effect of the D–A structure on hydrogen generation properties. After these polymers were prepared into polymer dots (Pdots) through the nanoprecipitation method, they exhibited excellent hydrogen generation properties. We found that PFO-Pdots obtained a hydrogen generation rate of 0.74 mmol g^–1 h^–1, and PFBT-Pdots with the D–A structure had about three times the hydrogen generation rate (2.23 mmol g^–1 h^–1) of PFO-Pdots, while PFVA-Pdots in the presence of the D–D structure obtained only one-half of the hydrogen generation rate (0.34 mmol g^–1 h^–1) of PFO-Pdots. These results indicated that the D–A structure plays a critical role in enhancing the photocatalytic hydrogen generation performance of organic semiconductor polymers. This will motivate organic polymers to take advantage of their structural tunability and enable further development in the field of photocatalytic hydrogen generation.

Polyimide (PI) aerogel with high thermal stability and low thermal conductivity exhibits significant application value in the aerospace field. Nevertheless, traditional preparation methods of PI aerogel face the challenges of a complicated manufacturing process and low mechanical strength, which severely restrict their industrial scalability. Herein, a series of PI aerogels with a stable topological porous hierarchy were designed and fabricated through synergistic chemical imidization and salt template strategies. This topological porous hierarchy is composed of micropores with sizes of 5–15 μm and macropores with sizes of 200 μm–1000 μm, respectively. The fabricated PI aerogels show lightweight (0.03–0.06 g/cm³), exceptional mechanical strength, and flame-retardant properties. In particular, the PI aerogels show ultralow thermal conductivity of 0.028 W/(m·K), demonstrating outstanding thermal insulation characteristics. Moreover, the conductive PI@PPy composite aerogels were designed by depositing pyrrole (PPy) within the matrix of aerogels, and the potential applications as flexible piezoresistive sensors and photothermal conversion devices were investigated. The prepared PI aerogels demonstrate great application potential in the fields of aerospace and microelectronics.

Polymer-based particulate materials are useful in various industries, but nondegradable polymeric particulate materials that generate microplastics pose challenges. Herein, we synthesized main-chain degradable polymer particles by radical ring-opening polymerization (rROP) in a miniemulsion system (miniemulsion rROP), in which dibenzo[c,e]oxepan-5-thione (DOT) was selected as the ring-opening monomer. Miniemulsion rROP of DOT and typical vinyl comonomers (styrene: St and n-butyl acrylate: nBA) was performed. The polymerization rate of the miniemulsion rROP was significantly higher than that of solution rROP. The DOT feed molar ratio in the miniemulsion rROP was increased to 20 mol % with high conversion. Colloidally stable poly(St-DOT) particles were successfully synthesized and were degraded by amine compounds in homogeneous and heterogeneously dispersed systems. Additionally, when nBA was used as the vinyl monomer, colloidally stable main-chain degradable poly(nBA-DOT) particles were successfully synthesized, and their degradation was observed with n-propylamine, evidencing the possibility of using miniemulsion rROP to synthesize degradable polymer particles.