Copper oxides and internal stress have an obvious influence on adhesion strength of copper deposited polymer composites. However, the effect of the evolution behavior of copper oxides and internal stress on adhesion force of chip substrates is no clear and rare far. Herein, the copper deposited epoxy-phenolic/silica composite film with different desmear time was fabricated by using wet chemistry and electrochemistry methods. The chemical structure, surface roughness, morphology, surface chemical state, crystal structure and adhesion strength of copper and epoxy resin substrate were characterized by scanning electron microscope (SEM), interference microscope, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The adhesion strength of samples is increased from 3 N/cm to 4.7 N/cm. The effect of the evolution behavior of copper oxides and internal stress on adhesion strength of copper deposited epoxy resin composite films at the interfaces was systematically investigated, the mechanisms and reason of increasing adhesion strength and interfacial adhesion failure for copper deposited epoxy resin composite substrates were revealed. This work will provide a guidance in theory and experiment to enhance interfacial adhesion force of epoxy resin composite films for advanced substrate in the future.

High adhesion force of chip substrates is crucial for improving chip reliability in the field of microelectronics.

We demonstrate that introduction of heterostructure nanoparticles into a polymer matrix is an effective strategy to substantially enhance dielectric breakdown strength (Eb) and thus a high electrostatic energy storage density (Ue) can be obtained, which is highly desired in modern electronic and electrical systems for energy storage and conversion. This is realized through the special "electrical rectification" effect of heterostructure nanoparticles on the charge transport, which stems from capturing and confining charge carriers in the nanocomposites by po-tential well and potential barrier formed at the heterojunction of ZnO-ZnS nanoparticles. The leakage current of the ZnO-ZnS/polyetherimide nanocomposites (ZnO-ZnS/PEI) is suppressed by the introduced heterojunction, which is accompanied with the simultaneous increase of dielectric displacement and charge-discharge efficiency, resulting in significant enhancement of Ue. Notably, the 1 wt% ZnO-ZnS/PEI nanocomposite films possess high discharged energy density at room temperature, i.e. 6.9 J cm-3 at 650 MV m-1, and even at 150 degrees C, the Ue still remains 3.6 J cm-3 at 500 MV m-1. Outstanding fatigue resistance over 50,000 charge-discharge cycles at 200 MV m-1 and 150 degrees C demonstrates high temperature cyclic stability of the heterostructure in confining charge carriers. This work provides a novel and scalable strategy to obtain polymer-based dielectrics with superior energy storage performance.

In general, although abundant literature studies are available on epoxy resin systems, a complete description of the curing kinetics in epoxy-cyanate ester composites relevant to the microelectronics industry is still lacking. Herein, curing behaviors of Ajinomoto build-up films, which are epoxy/silica composites, were studied by the non-isothermal differential scanning calorimetry method, and then, three non-isothermal curing kinetics models and model-free curing methods were used to analyze curing behaviors. In addition, a copper layer was also deposited onto the surface of the build-up film, and its interfacial adhesion property was also analyzed at different pre-curing conditions. The results showed that the curing reaction of the build-up film contains two curing reaction processes, and the first curing process is suited for the autocatalytic curing model, while the other curing process is suited for the Kamal curing kinetics model. Three model-free curing methods were used to calculate the activating energy at different degrees of curing, which indicated that the activating energy is variable during the whole curing process. The interfacial adhesion strength between the build-up film and copper layer decreased with the increase in the degree of curing, which is attributed to the contribution of mechanical anchoring. This work will offer guidance in curing behaviors for improving interfacial bonding force and controlling warpage behavior for chip substrates in the future.

Ajinomoto build-up film, a polymer composite composed of epoxy resin and silicon dioxide, exhibits a significant value in the microelectronics industry due to its low dielectric constant, low dielectric loss, low processing temperature, and excellent resin flowability. It has emerged as a cutting-edge and hot research topic in chip packaging substrates. This article provides an overview of the research progress on copper plating on the surface of Ajinomoto build-up films, primarily discussing the curing reaction mechanism, fundamental properties, and fabrication process, adhesion measurement method and surface characterization techniques of copper plating on Ajinomoto build-up film; elucidating the interface adhesion mechanism between the polymer film and copper plating, and exploring methods to enhance the interface adhesion strength of the Ajinomoto build-up film. Finally, the article summarizes the current challenges and limitations in copper plating on Ajinomoto build-up film, and highlights future directions of research and development.

For self-healing polymers, obtaining excellent healing ability and mechanical properties usually need complex chemical structure, external healing conditions, and high manufacturing difficulty. Therefore, self-healing efficiency and rate, mechanical strength, and simple structure design as well as no additional healing conditions of the material are contradictory properties and are difficult to optimize simulta-neously. Herein, self-healable thermoplastic poly (urethane urea) elastomers driven by surface energy were fabricated by the introduction of asymmetric alicyclic structures and the healing properties in polymers were optimized by regulating surface energy. The results showed that with the increasing of isophorone diamine contents, the surface energy driving force increased from 36 kPa to 149 kPa, the healing time decreased from 30d to 5d, and healing efficiency, and tensile strength reached 100.9% and 4.04 MPa at room temperature. At the same time, polymers also obtained a high healing efficiency under high-temperature healing conditions. The healing mechanism is that asymmetric alicyclic structures with steric hindrance and ring flip promote the dissociation of hydrogen bonds, provide sufficient chain mobility, decrease the junction density, and improve the surface energy as well as the dissociation and reconstruction of hydrogen bonds. Energetic polymer composites using thermoplastic poly (urethane urea) elastomers as matrix obtained excellent healing properties. This study will offer a novel healing approach for developing advanced self-healing polymer materials.(c) 2022 Published by Elsevier Ltd.

As the typical insensitive propellants, hydroxyl-terminal block copolyether (HTPE) and hydroxyl-terminal block copolyether (PET) propellant all belong to copolyether propellants. The two binders of propellants have different arrangements of copolyether structure. But, the effect of copolyether structure arrangement on the slow cook-off behavior of propellants and its possible mechanism has been unknown. So, in this paper, the slow cook-off behaviors of HTPE and PET propellants were tested. The result showed PET propellant responded more violently than HTPE propellant. Then, the changes of mass loss, explosion heat, and combustion performance of propellants during the cook-off test were studied. Combined with the slow cook-off behavior of AP and binders, the mechanism of block structure effect on slow cook-off response of propellant was proposed. It expressed that, the binders of HTPE and PET propellant all degraded into liquid products due to the copolyether structure; but the block structure has a significant effect on the chain scission process of copolyether binder, which makes slight degradation and the mild response to slow cook-off for HTPE propellant. While the binder of PET propellant with the random structure degraded seriously, making more mass loss, bigger explosion heat, and worse combustion performance, the PET propellant responds violently to slow cook-off.

The 1,5-Cyclooctadiene (COD) and dicyclopentadiene (DCPD) copolymers prepared by step-wise polymerization (CD-SP) can simultaneously enhance the tensile strength and breaking elongation of polymers, compared with those prepared by frontal polymerization (CD-FP). For example, the stress and strain of the 30%CD-SP are 2.7 times and 1.8 times that of 30%CD-FP, respectively. This step-wise polymerization (SP) is determined by the curing kinetic parameters and the conversion difference of COD and DCPD by non-isothermal DSC and non-model kinetics (MFK method), that is, SP: 35 degrees C, 4 h; 60 degrees C, 30 h. In addition, energetic composite materials consisting of 85% solid fillers and COD-DCPD copolymers are prepared by SP, and its mechanical properties are far better than those of traditional energetic composite materials. Specifically, the breaking elongation increases from less than 100% to more than 500%, and the tensile strength is higher than 1 MPa. It is expected to be used as a new binder in energetic composite materials and other composite materials.

In general, ultrahigh loading fillers can increase the hardness and hinder the interfacial healing progress in polymer composites. Therefore, the healing ability and mechanical strength of polymer composites with ultrahigh filler loading are contradictory properties and are difficult to optimize simultaneously. Herein, self-healing hard polymer composites consisting of 72.4 vol% fillers and self-healing thermoplastic elastomers based on surface energy and disulfide bonds were fabricated. The results showed that in the case that of ultrahigh filler loading, polymer composites not only obtained a high mechanical strength of -3.21 MPa and a high self-healing efficiency of -92.8%, but also possessed the strong reshape ability. Besides, a physical model was used to describe the self-healing mechanism. The adhesion effectively closed cracks and the surface energy driven the movement of polymer chains as well as disulfide bonds reconstructed new polymer chains at the interfaces, resulting in recovering heal mechanical property.

含能热塑性弹性体结合了含能材料和热塑性材料的特点,具有能量高、感度低、燃尽性好、可再加工、可回收利用等优点,在火炸药领域具有重要的应用价值,成为含能材料研究的前沿与热点.综述了含能热塑性弹性体的研究与应用进展,重点阐述了官能团预聚体法、活性顺序聚合法和大分子引发剂法等合成方法;介绍了直接法、间接法、溶液法和本体法制备工艺;总结了相关的结构表征和基本性能,如链段组成及序列、微相分离、氢键化和结晶度以及热分解、感度、相容性、流变、生成焓和燃烧性能等;阐明了构建键合和自修复功能以及提升力学性能和能量水平的方法;论述了含能热塑性弹性体在发射药、混合炸药、固体推进剂和可燃药筒及改性球形药等方面的应用进展,总结了目前存在的问题和不足,指出了未来研究和发展的主要方向.

Silver–thiol coordination interactions were introduced into a waterborne polyurethane (WPU) matrix. Due to the synergy of the Ag and thiol coordination interactions, WPU–Ag@S-0.50 exhibits the best self-healing performance.

Covalent functionalization of black phosphorus nanosheets (PNs) exhibit relatively stability, but one unpaired electron still retains in the phosphorus atom, rendering unsaturated coordination state and hampering the passivation effect. Azide functionalization achieves the five-coordinate bonding of phosphorus atoms, making PNs completely passivated. But a molecule with an azide group is extremely dangerous owing to explosive and corrosive nature. Herein, insensitive glycidyl azide polymer, GAP, was the first used for covalent azide functionalization of PNs to generate GAP-PN of P=N bond with the best stability. The structure of GAP-PN was comprehensively confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), the atomic force microscopy (AFM), Raman spectra, solid-state 31P nuclear magnetic resonance spectroscopy (31P NMR), x-ray photoelectron spectroscopy (XPS) and the elemental analysis. The average statistical size and the thickness of GAP-PN is 2.46 ± 1.51um and10.4 nm.The stabilization mechanism was explored via XPS, and the mechanism was attributed to the chemical modification of the surface of PNs with P=N bond formation, which inhibits the formation of PxOy. The stability properties of GAP-PN were evaluated by XPS and the UV/Vis spectroscopic. The experimental results show that the degradation ratio of GAP-PN decreased from 54.9 to 8.8% of PNs after 60 days. In addition, compared with PNs, the peak temperature corresponding to exothermic phase(TP) of GAP-PN decrease by 44.6 °C and heat released during the decomposition for GAP-PN is up to is 3154.9 J/g, which is 6.09 times higher than that of PNs. This work provides a novel strategy for the stability study of PNs, which is supposed to possess significant potential in the nanocomposite energetic materials applications field.

Overcoming the severe particle agglomeration of unreacted fuel boron (B) in combustion process to en-hance the heat release efficiency of B-based fuel-rich propellants is still a great challenge. Glycidyl azide polyether (GAP) was introduced to synthesize GAP-based energetic thermoplastic elastomer (GAP-ETPE) binder, which was used to fabricate the B/GAP-ETPE propellant. High GAP content (85 wt%) can be used to synthesize 85%GAP-ETPE as the binder. With the increase of GAP content, the decomposition conversion rate of GAP-ETPE was increased and the apparent activation energy (E-a) of B/GAP-ETPE propellant was decreased. The heat of explosion and combustion of B/85%GAP-ETPE were increased from 4004.1 kJ/kg to 4546.2 kJ/kg and 24,056.5 kJ/kg to 24,938.3 kJ/kg, respectively. The combustion results showed that the burning rate of B/85%GAP-ETPE (3.1 mm/s) was higher than that of B/TPE (1.8 mm/s) using a ther-moplastic elastomer (TPE) without GAP, and the particle injection effect was significantly improved. The pressurization rate of B/85%GAP-ETPE (85 wt% is maximal GAP content in binder in current study) was 2.6 MPa/s during combustion in a closed bomb, which was higher than that of other prepared B/GAP-ETPE, showing the propellant using GAP-ETPE with high GAP content exhibited better gas formation and higher heat release, which provided good dispersion and less particle agglomeration of B particles when burning. This strategy enables B to be ejected more effectively in the combustion process to achieve a better combustion performance and heat release. (C) 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Direct writing technology is a promising approach for the preparation of reactive materials. The polymer binder provides a mechanically stable, processable and shapeable energetic structure for composites. Herein, Direct-writing energetic inks consisting of nitrocellulose (NC) and VitonF2311 as well as nanothermite were developed. Firstly, Fourier transform infrared spectroscopy (FT-IR) was used to analyze the intermolecular hydrogen bonds in the hybrid polymers, and the stability of the network structure was characterized by rheometer, and the mechanical properties of binders were also tested. The results show the best binder formulation is 20 wt% NC and 80 wt% F2311. The elongation at break of the binder is 600.94%, and the elastic modulus is 8.29 MPa. NC provides high tensile strength for the hybrid binder; F2311 provides high fracture tensile rate for the hybrid binder, and as a high-energy initiator, pre-ignition reaction occurs when the temperature reaches 350 °C. Then the as-prepared inks not only has excellent rheological properties so that it can be loaded with 90 wt% nanothermite, but also possess a homodisperse for components and good combustion performance. The average flame temperature is about 2400 K at atmospheric pressure.

Nano-copper oxide (CuO) is a commonly used ammonium perchlorate (AP) catalyst, but the nano-CuO particle have obvious reunion phenomenon, which hinders the effective contact area of CuO and AP, and makes the catalytic effects is not ideal. To improve the catalytic effect of nano-CuO, CuO/GO nanocomposites were prepared under different conditions with graphene oxide (GO) as the carrier. Transmission electron mirror (TEM), scanning electron mirror (SEM), X-ray diffraction (XRD) were used to characterize the structure and TG-DSC was used to study the effect on the thermal decomposition performance of AP. The best result show that nanocomposite reduced the peak temperature of AP to 329.6 ℃ by 77.7 ℃, while the release heat increased from 826.2 J/g of pure AP to 2019.2 J/g by 1193 J/g.

采用异佛尔酮二异氰酸酯、聚丙二醇和2,2-二羟甲基丙酸为主要原料,以无卤含磷阻燃剂Exolit OP550(记为OP550,下同)为软段扩链剂,通过前扩链方式将二羟乙基二硫化物引入到水性聚氨酯(WPU)分子链中,成功制备了兼具阻燃和自修复两种特殊功能的水性聚氨酯(记为OHWPU)乳液.采用FTIR和激光粒度仪对OHWPU结构及乳液性能进行了表征,通过热重分析仪、万能试验机、极限氧指数仪及锥形量热仪考察了OP550对OHWPU胶膜热性能及自修复性能的影响.结果表明,OP550含量为反应物总质量的20％时,制备的OHWPU-20％胶膜的极限氧指数达到29.0％,比对应的无OP550水性聚氨酯胶膜提高了7.4％;在80℃,修复时间为3.0 h条件下,OHWPU-20％胶膜损伤修复后的拉伸强度为4.64 MPa,自修复效率达到107.9％.

Polymeric materials that simultaneously possess excellent mechanical properties and high self-healing ability at room temperature, convenient healing, and facile fabrication are always a huge challenge. Herein, we report on surface-energy-driven self-healing energetic linear polyurethane elastomers (EPU) that were facilely fabricated by two-step methods to acquire high healing efficiency and mechanical properties. By constructing surface energy and dynamic hard domains, energetic linear polyurethane elastomers not only obtained high healing ability and mechanical properties at high or room temperature but also avoid the use of some assisted healing conditions and complex chemical structure design and decrease manufacturing difficulty. Based on the interfacial healing physical model, various trends of surface tension, radius, and depth of the crack bottom were calculated to analyze the healing mechanism. We propose that polyurethane elastomers with low junction density could generate excess surface energy resulting from damage and drive self-healing, and incorporating a small amount of disulfide bonds increases the slightly packed hard phase and decreases the healing energy barrier. This work may offer a novel strategy for improving mechanical tensile and healing ability in the field of self-healing material application.

The curing kinetics between PGN and N100 were studied by Fourier transform infrared spectroscopy and dynamic torsional vibration method. The results showed that the entire curing process of adhesives was divided into three stages. Infrared spectroscopy can only monitor the first and second stages, while dynamic torsional vibration method monitors the second and third stages. Combining the two analysis methods allows the complete monitoring of the entire curing process in this system. Besides, differential scanning calorimeter is not suitable for studying this process.

Polymer composites with self‐healing ability are highly desired for applications in advanced modern devices. Here, we report on self‐healing polymer composites consisting of silver deposited‐carbon nanotubes hybrid nanoparticles (CNT‐Ag) as fillers and self‐healable polyurethane (DAPU) as a matrix based on thermally reversible Diels‐Alder reaction. The results indicated that as the hybrid filler loading is 1 wt%, the composites not only obtained a high‐strength (~15.97 MPa) and high healing efficiency (~90.1%) by increasing filler loading after healing, but also enhance thermal conductivity (~1.65 Wm−1 K−1) and obviously shorten its healing progress in comparison with other composites in the case of the same healing time. Given that Ag_NPs deposited on the surfaces of the CNTs act as bridges to link the adjacent CNTs and reduce interfacial thermal resistance, which can effectively explain the reasons for the obtained high mechanical strength and healing efficiency and promoting healing progress in the polymer composites. This work may offer a novel strategy for balancing relation between mechanical property, healing ability and healing progress in the field of self‐healing materials application.

In general, acquiring highly efficient recovery and speed needs additional healing conditions or complex chemical structures under typical ambient conditions and intervention, making it difficult to optimize them simultaneously. Herein, self-healable polyurethane materials driven by stronger surface energy were fabricated by two-step methods to acquire high healing speed and efficiency as well as mechanical property. The obtained films have a high healing efficiency and tensile strength as well as a shorter healing time without requiring additional healing conditions and complex chemical structures at room temperature. Incorporating diethyl bis(hydroxymethyl)malonate can tune loosely packed hard domains, molecule chain mobility, and surface energy, which leads to a low junction density that helps increase the surface energy driving force and accelerate self-healing. This self-healable polyurethane will offer an effective guide and reference for designing high-performance self-healing materials in the future.