Comparison Of Mechanical Properties Research Articles

High-Energy Laser Protection Performance of Fibrous Felt-Reinforced Aerogels with Hierarchical Porous Architectures.

Continuous-wave lasers can cause irreversible damage to structured materials in a very short time. Modern high-energy laser protection materials are mainly constructed from ceramic, polymer, and metal constitutions. However, these materials are protected by sacrificing their structural integrity under the irradiation of high-energy lasers. In this contribution, we reported multilayer fibrous felt-reinforced aerogels that can sustain the continuous irradiation of a laser at a power density of 120 MW·m-2 without structural damage. It is found that the exceptional high-energy laser protection performance and the comparable mechanical properties of aerogel nanocomposites are attributed to the unique characteristics of hierarchical porous architectures. In comparison with various preparation methods and other aerogel materials, multilayer fibrous felt-reinforced aerogels exhibit the best performance in high-energy laser protection, arising from the gradual interception and the Raman-Rayleigh scattering cycles of a high-energy laser in the porous aerogels. Furthermore, a near-zero thermal expansion coefficient and extremely low thermal conductivity at high temperature allow the lightweight felt-reinforced aerogels to be applied in extreme conditions. The felt-reinforced aerogels reported herein offer an attractive material that can withstand complex thermomechanical stress and retain excellent insulation properties at extremely high temperature.

Experimental Investigation on Mechanical and Durability Properties of Geopolymer Concrete

Abstract: Geopolymer concrete (GPC) is a new type of concrete that is made with alkaline activators and aluminosilicate materials, such as fly ash and ground granulated blast furnace slag (GGBS). GPC has several advantages over traditional Portland cement concrete (OPC), including higher early strength, better durability, and lower environmental impact. This paper presents an experimental analysis of the mechanical and durability properties of GPC. The mechanical properties investigated include compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity. The results show that GPC has comparable or better mechanical properties than OPC at all ages. GPC also has superior durability properties to OPC, with lower water absorption, higher acid resistance, and lower chloride permeability. The overall findings of this study indicate that GPC is a promising alternative to OPC for a wide range of applications. Since Geopolymer concrete doesn’t use any cement, the production of cement shall be reduced and hence the pollution of atmosphere by the emission of carbon dioxide shall also be minimized. Cement, being a key material of concrete, experiencing a rise in global demand. It has a massive carbon footprint having a contribution of about 8% to the global Carbon dioxide emissions. Geopolymer concrete has a huge potential to replace ordinary Portland concrete. For sustainable construction, GPC reduces the use of cement and finds the alternative of cement for the material's binding property. So, the geopolymer concrete is an alternative to Portland cement concrete and it is a potential material having large commercial value and for sustainable development in Indian construction industries.

Decellularized kidney capsule as a three-dimensional scaffold for tissue regeneration.

Tissue regeneration is thought to have considerable promise with the use of scaffolds designed for tissue engineering. Although polymer-based scaffolds for tissue engineering have been used extensively and developed quickly, their ability to mimic the in-vivo milieu, overcome immunogenicity, and have comparable mechanical or biochemical properties has limited their capability for repair. Fortunately, there is a compelling method to get around these challenges thanks to the development of extracellular matrix (ECM) scaffolds made from decellularized tissues. We used ECM decellularized sheep kidney capsule tissue in our research. Using detergents such as Triton-X100 and sodium dodecyl sulfate (SDS), these scaffolds were decellularized. DNA content, histology, mechanical properties analysis, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), biocompatibility, hemocompatibility and scanning electron microscope (SEM) imaging were measured. The results showed that the three-dimensional (3D) structure of the ECM remained largely intact. The scaffolds mentioned above had several hydrophilic properties. The best biocompatibility and blood compatibility properties were reported in the SDS method of 0.5%. The best decellularization scaffold was introduced with 0.5% SDS. Therefore, it can be proposed as a scaffold that has ECM like natural tissue, for tissue engineering applications.

A Dynamic Ultrasound Phantom with Tissue-Mimicking Mechanical and Acoustic Properties.

Tissue-mimicking phantoms are valuable tools that aid in improving the equipment and training available to medical professionals. However, current phantoms possess limited utility due to their inability to precisely simulate multiple physical properties simultaneously, which is crucial for achieving a system understanding of dynamic human tissues. In this work, novel materials design and fabrication processes to produce various tissue-mimicking materials (TMMs) for skin, adipose, muscle, and soft tissue at a human scale are developed. Target properties (Young's modulus, density, speed of sound, and acoustic attenuation) are first definedfor each TMM based on literature. Each TMM recipe is developed, associated mechanical and acoustic properties are characterized, and the TMMs are confirmed to have comparable mechanical and acoustic properties with the corresponding human tissues. Furthermore, a novel sacrificial core to fabricate a hollow, ellipsoid-shaped bladder phantom complete with inlet and outlet tubes, which allow liquids to flow through and expand this phantom, is adopted. This dynamic bladder phantom with realistic mechanical and acoustic properties to human tissues in combination with the developed skin, soft tissue, and subcutaneous adipose tissue TMMs, culminates in a human scale torso tank and electro-mechanical system that can be systematically utilized for characterizing various medical imaging devices.

Axial compressive behavior and failure mechanism of CFRP partially confined ultra-high performance concrete (UHPC)

With comparable mechanical properties, higher cost-effectiveness and ease of column joints rehabilitation, partial fiber-reinforced polymer (FRP) confinement holds promise as an alternative to full FRP confinement in ultra-high performance concrete (UHPC). Nevertheless, the compressive behavior and underlying failure mechanism of FRP partially confined UHPC are not fully understood. To address this issue, axial compression tests on ultra-high strength concrete (UHSC, removing fibers in UHPC) and UHPC cylinders fully and partially confined by FRP are conducted in this study. The stress-strain relationship, strain distribution and crack development of specimens subjected to axial compression are profoundly analyzed using a combination of strain gauges and digital image correlation (DIC). Experimental results indicate that partial FRP confinement has a comparable effect on compressive performance compared to full FRP confinement. FRP confinement and fiber inclusion can effectively overcome the brittle nature of UHSC in compressive failure and consequently extend the transition stage, raising the stress/strain retention ratio from 0.91% to 26.45% and improving the enhancement ratio of ultimate strain from 1.97% to 34.4%. Furthermore, a more reliable and accurate prediction model is proposed in this study for evaluating the stress-strain relationship of partial FRP confinement under ultimate conditions.

Performance of Flax/Epoxy Composites Made from Fabrics of Different Structures

Flax fibers have been shown to have comparable mechanical properties to some conventional synthetic fibers. Flax fabrics with different textile structures show differences in resistance against mechanical loads mainly rooted in fabric orientation and the resultant resin impregnation. Thus, in this study, flax fabrics with three different textile structures, fine twill weave, coarse twill weave and unidirectional, were used as reinforcements in an epoxy matrix. The surfaces of the fabrics were chemically treated using an alkaline treatment, and the alterations in fabric crystallinity index (CrI) were determined using X-ray diffraction (XRD). Experimental results confirmed that textile structures and CrI had significant effects on the mechanical properties of composites. Although an increment in CrI, resulting from chemical treatment, always enhanced tensile and flexural properties, it adversely affected damage development once composites were exposed to impact load. In terms of textile structures, unidirectional fabric outperformed woven fabrics in tensile and flexural properties while in impact properties, the latter had a better performance inducing less damage development. Finally, the mechanism of damage development in different composites was discussed in detail using Scanning Electron Microscopy (SEM) images. It is envisaged that the results of this study will provide an insight that will lead to the proper choice of the optimal kind of flax fabric for different applications.

Characterization of recycled nitrile butadiene rubber industrial scraps

The amount of rubber scraps derived from rubber goods production consists of about 20–30% of the processed material, so it is necessary to enhance this material by developing new recycling techniques as well as a new market for recycled rubber products. In the present research, nitrile-butadiene rubber (NBR) scraps are reprocessed via a calendering process acting with a mechanical devulcanization. Compounds were prepared with 20%, 80%, and 100% recycled rubber content and characterized. The experimental results highlighted that the compound prepared with 20% recycled rubber content via calendering and compression molding processes shows comparable mechanical properties to that of virgin NBR. The tensile properties are the most penalized by the increasing content of recycled material (100% recycled shows − 25% and − 50% stress and strain at break, respectively). Other properties remain comparable to the standard material up to 80% recycled material: 60 ± 5 Shore A, compression elastic modulus 8 MPa, compression set 20%. FTIR analysis revealed no changes in chemical structure from the recycling process. The results demonstrate that simple mechanical devulcanization can effectively reprocess industrial rubber waste while largely maintaining useful properties. This provides a potential pathway to enhance sustainability in rubber production through the valorization of process scraps.Graphical

Self-catalysed frontal polymerisation enables fast and low-energy processing of fibre reinforced polymer composites

Frontal polymerisation has the potential to bring unprecedented reductions in energy demand and process time to produce fibre reinforced polymer composites. Production of epoxy-based fibre reinforced polymer parts with high fibre volume content, commonly encountered in industry, is however hindered by the heat sink created by the fibres and the mould, overcoming the heat output of the chemical reaction, thus preventing front propagation. We propose a novel self-catalysed frontal polymerisation manufacturing method based on the integration of thin resin channels in thermal contact with the composite stack as a strategy for low-energy production of high fibre volume fraction polymer composites without the need for a continuous energy input. Frontal polymerisation inside the resin channel proceeds faster and preheats the fabric stack, thus catalysing the process. Parts with up to 60% fibre content are successfully produced independently of the sample thickness. Fillers added within the resin channels provide means to tailor the frontal polymerisation process kinetics. The parts have a significantly higher glass transition temperature than those produced in a conventional oven, and comparable mechanical properties while energy consumption is reduced by over 99.5%.

Valorization of wood ash for sustainable in situ reinforced Ti composites with tailorable mechanical behavior manufactured via powder metallurgy

The aim of this work is to investigate the feasibility of revalorizing commonly disposed wood ash as source to produce more sustainable in situ reinforced Ti composites. We propose a manufacturing process based on the powder metallurgy green technology and further increase the energy efficiency of the process by analyzing reactive induction sintering as the primary consolidation method. The feasibility of the proposed approach is demonstrated through the characterization of the physical, microstructural, and mechanical performance. It is found that compressibility decreases and the amount of residual porosity increases (6.0–11.7% for pressureless sintering) with the amount of wood ash used (0–0.25 wt%). However, the effective in situ creation of the reinforcement is always guaranteed by the proposed approach. Furthermore, minor adjustments of the manufacturing route can be used to maximize the amount of ash to be added for higher sustainability. The in situ reinforced Ti composites are commonly characterized by both elastic and plastic deformation and fail non-catastrophically, where for vacuum sintering ductility decreases (13.7 → 8.7%) but strength (497 → 653 MPa) and hardness (47.8 → 55.0 HRA) increase with the amount of ash used. The in situ reinforced Ti composites produced from revalorized wood ash have overall comparable or better mechanical properties in comparison to other Ti-based composites bearing a higher amount of generally more expensive reinforcements.

Advancing Sustainable Solutions: Exploring United Atom Model for Efficient Molecular Dynamics Simulation of Poly-ethylene Vanillic (PEV) Polymer

The development of green polymers is a crucial long-term solution to address the problem of plastic waste. In particular, the bio-based polymer polyethylene vanillic (PEV) has garnered interest due to its comparable mechanical and thermal properties to polyethylene terephthalate (PET), a widely used single-use plastic. Molecular dynamics (MD) simulations are commonly employed to study the molecular structure and dynamic properties of materials, offering cost-effective applications. However, the accuracy of MD simulation results heavily relies on the chosen force field model. The all-atom (AA) force field, while providing insights into molecular interactions, demands significant computational resources, especially for large systems like polymers. This study aimed to employ the united atom (UA) model with revised OPLS-UA force field parameters for the biopolymer PEV, aiming to reduce computational time in dynamic and physical investigations. Consequently, the UA model successfully folded the PEV polymer in a manner resembling the single-chain PEV treated with the AA model, while also predicting a glass transition temperature (Tg) close to the experimental value of 348 K. These findings underscore the potential of the UA model for simulating PEV and its promising implications.

Recycled glass powder as an alternative to fly ash in non-proprietary UHPC: A comparative study of resource-efficient design, mechanical and durability properties

Fly ash (FA) is one of the preferable supplementary cementitious materials used in the design of resource-efficient ultra-high performance concrete (UHPC). Recent changes in energy production have led to a reduced availability of FA which increases the need to find an alternative replacement. One suitable, innovative, and sustainable pozzolan with higher consistency in material properties is recycled glass powder (RGP), produced from 100% post-consumer glass. To fill the knowledge gap whether RGP is a suitable alternative to FA in non-proprietary UHPC, this research emphasizes the comparative investigation of material properties of UHPC using FA versus RGP. The comprehensive material characterization and analysis included workability, mechanical behavior such as compressive strength, single fiber pull out and direct tensile behavior, static elastic modulus, and long-term strength. Durability properties included electrical surface resistivity and freeze-thaw resistance. In addition, a comparative analysis for their resource-efficiency and service life was also performed. The results were compared to two commercial UHPCs, available in the United States. This research showed that UHPC with RGP can be designed to achieve comparable mechanical and durability properties as UHPC with FA. Compressive strength up to 176 MPa (25.5ksi) were obtained without the use of special treatment, at current material cost of about US$1145/m3 with 2% of fiber volume fraction of steel fibers. Over time, the compressive strength of UHPC with RGP increased by 15%, resulting in more than 200 MPa (29.0ksi) after three years. Both UHPCs designed with either FA or RGP showed strain-hardening under direct tension with maximum tensile strength of about 14.8 MPa (2.1ksi). Both the UHPC with RGP and FA achieved electrical surface resistivity of more than 870kΩ × cm and 822kΩ × cm in 28 days and relative dynamic modulus of 102% after 600 freeze-thaw cycles that ensure long term durability with design service life of 364 and 344 years respectively.

Mechanical, metallurgical, and corrosion investigations on wire arc additively manufactured low carbon steel

Current global 3D metal printing research is focused on powder bed fusion and direct energy deposition. Several materials are presently under research to assess their post-additive manufacturing properties, and to process them in industries using advanced manufacturing techniques. This study investigates the electrochemical, mechanical, and metallurgical properties of wire arc additively manufactured (WAAM) ER70S-6 alloy walls on AISI S235 plates, emphasizing ship component fabrication. The corrosion resistance of both materials is assessed through Electrochemical Impedance Spectroscopy and Potentiodynamic Polarization testing in a 3.5% NaCl solution. Surface and cross-sectional morphologies are analyzed using optical microscopy and scanning electron microscopy, while energy dispersive spectroscopy is employed to study the chemical composition of the corrosion products. Moreover, the hardness of the WAAM-deposited ER70S6 wall is found to be highest in the uppermost layers of deposition due to the presence of acicular ferrite and ferritic-bainite microstructure. Tensile and Charpy impact strength for AISI S235 and WAAM-deposited ER70S-6 exhibit similar performance at room and low temperatures. Interestingly, the WAAM sample demonstrates a 60% higher elongation than the AISI S235 sample. Hence, the findings from this experimental work suggest that WAAM-deposited carbon steel exhibits favourable corrosion resistance and comparable mechanical properties to AISI S235. Consequently, WAAM is emerging as a promising alternative to conventional manufacturing techniques for fabricating ship components, repairing and modifying hull structures, manufacturing nozzles, propeller blades, fin-like structures, structural components, and more.

Preparation of calcium phosphate ion clusters through atomization method for biomimetic mineralization of enamel.

Dental enamel is a mineralized extracellular matrix, and enamel defect is a common oral disease. However, the self-repair capacity of enamel is limited due to the absence of cellular components and organic matter. Efficacy of biomimetic enamel mineralization using calcium phosphate ion clusters (CPICs), is an effective method to compensate for the limited self-healing ability of fully developed enamel. Preparing and stabilizing CPICs presents a significant challenge, as the addition of certain stabilizers can diminish the mechanical properties or biosafety of mineralized enamel. To efficiently and safely repair enamel damage, this study quickly prepared CPICs without stabilizers using the atomization method. The formed CPICs were evenly distributed on the enamel surface, prompting directional growth and transformation of hydroxyapatite (HA) crystals. The study revealed that the mended enamel displayed comparable morphology, chemical composition, hardness, and mechanical properties to those of the original enamel. The approach of repairing dental enamel by utilizing ultrasonic nebulization of CPICs is highly efficient and safe, therefore indicating great promise.

Effects of Structurally Different Tertiary Amines on the Properties of Quaternized Anionic Exchange Membranes Potentially Applicable for Water Electrolysis.

In this work, two structurally different monoamines (trimethylamine [TMA] and N-methylpiperidine [N-MPip]) are used for the amination of a g-VBC-15 graft copolymer, obtained by the functionalization of a mechanically robust, commercially available styrene-butadiene block copolymer (SB) with vinylbenzyl chloride (VBC) via solution free-radical polymerization. Results demonstrate that g-VBC-15-based membranes quaternized with TMA have superior electrochemical performance than N-MPip counterparts; while, the mechanical properties are good and only slightly inferior to those of N-MPip. Therefore, TMA is the selected monoamine to be alternatively mixed with two polyamines (tetramethyl-1,3-propanediamine [TMPDA] and N,N,N',N'',N''-pentamethyldiethylenetriamine [PMDETA]) into different proportions, in order to modulate the average functionality of the amination mixture in terms of number of amine functional groups available for the quaternization reaction of the membranes. g-VBC-15-based membranes derived therefrom are extensively characterized to assess their thermal, mechanical, and ex situ electrochemical properties. Results indicate that membranes quaternized with a TMA/PMDETA mixture (90:10 in mole) display the highest conductivity among all the investigated membranes aminated with polyamine-based mixtures. Moreover, they have comparable mechanical and electrochemical properties to those quaternized with TMA, while exhibiting a reduced water uptake.

Investigation of Sandstone-like Material for Damaged Rock Mass Based on Orthogonal Experimental Method

The investigation of the mechanical properties of rock mass can be effectively carried out through rock-like material experiments. In this study, polystyrene foam particles were utilized as a novel material for simulating initial damage within rocks. Our research involved the development of sandstone-like materials with comparable mechanical properties to actual sandstone. These materials were then subjected to orthogonal mechanical tests, allowing us to identify the key factors that have a substantial impact on the mechanical parameters of sandstone-like rocks. The influencing factors considered in the orthogonal mechanical tests were the proportion of aggregate and binder, the proportion of polystyrene foam in the entire model, the proportion of binder and regulator, and the size of polystyrene foam. Five levels were set for each factor, and mechanical parameters such as compressive strength, tensile strength, elastic modulus, axial strain, and Poisson’s ratio were tested for each group of samples. The changes in mechanical parameters with the levels of the above four factors were studied. The study found that modifying the proportion of aggregate to binder can alter the elastic modulus, tensile strength, and compressive strength values of sandstone-like material. The size of polystyrene foam can be modified to alter the axial strain values of sandstone-like materials. Additionally, adjusting the ratio of binder and regulator can modify the value of Poisson’s ratio. The comparison of mechanical parameters between sandstone-like samples and sandstone reveals that sandstone-like materials can better simulate the deformation and failure mechanisms of sandstone. The error in the main mechanical parameters, such as modulus of elasticity, strength, and Poisson’s ratio, is less than 7%, indicating a greater resemblance between sandstone-like materials and sandstone. Therefore, sandstone-like materials can be used to investigate the deformation law, damage evolution law, and failure mechanism of sandstone. This can help alleviate the difficulty of obtaining specimens of deep damaged rock and the high cost of testing.

Investigation of viscoelastic behavior of Abaca-reinforced epoxy composites

Natural fiber-based composites demonstrate excellent and comparable static and dynamic mechanical properties to conventional materials, such as steel and aluminum. They also extend their applications to aeronautical, sports equipment, and marine fields. This experimental study aims to find the effect of untreated and treated Abaca-reinforced epoxy composites on the viscoelastic behavior and the optimum combinations of fiber and resin to produce better bonding efficiency. The different specimens used for this study were pure epoxy, untreated, and chemically treated composite specimens. The four weight percentages of Abaca fibers are 10%, 20%, 30%, and 40% used to prepare composite specimens. Similarly, four different sodium hydroxide (NaOH) concentrations, 4, 6, 8, and 10 wt. %/vol. %, have been used for the chemical treatment of fibers. The storage modulus of Abaca-reinforced epoxy composite specimen has been investigated with respect to temperature and fiber content. The result shows that the 30% weight fraction of fibers with chemically (8 wt. %/vol. %) treated fiber-reinforced epoxy specimen produces 41.67% higher storage modulus than the 10% weight fraction of fibers content of composite specimens. Fourier-Transform Infrared Spectroscopy (FTIR) broad transmittance has been used to distinguish the raw and chemically treated fibers. FTIR results reveal the removal of functional groups after NaOH treatment.

An engineered cardiac patch based on biodegradable thermoplastic elastomer fabricated by 3D printing and in situ polymerization

Fabricate on conductive engineered cardiac patches (ECPs) that closely resemble the mechanical properties of natural myocardium remains challenging. In this contribution, block copolymers of Poly(γ-methyl-Ɛ-caprolactone)-b-poly (Ɛ-caprolactone)-PEG-poly (Ɛ-caprolactone) -b-poly(γ-methyl-Ɛ-caprolactone) (PMECLs) via sequentially ring-opening polymerization (ROP) of Ɛ-caprolactone (CL) followed by γ-methyl-Ɛ-caprolactone (MCL) were achieved. The resulting PMECLs exhibited typical elastic characteristics of thermoplastic elastomers (TPEs) and demonstrated excellent adaptability to 3D printing. To enhance the conductivity of PMECL scaffolds, conductive polypyrrole (PPy) was in situ polymerized on the surface. As a result, electrically conductive ECPs that displayed comparable conductivity and mechanical properties to natural myocardium was successfully obtained. In vitro cellular experiments were conducted to evaluate the cytocompatibility of the ECPs, and it was found that they exhibited excellent cytocompatibility and supported cell proliferation for a duration of 7 days. Furthermore, the conductive ECPs demonstrated a significant enhancement in the expression of cardiac marker proteins (α-actinin, CX-43) in H9C2 cells, when compared to non-conductive ECPs. This finding suggests that the conductive ECPs played a crucial role in promoting cellular maturation and functionalization. Consequently, this conductive elastic ECPs holds great potential for application in the treatment of MI-damaged tissue.

Feasibility of using pretreated sodium silicate-bonded waste foundry sand as fine aggregates for construction mortar

Insufficient utilization of sodium silicate-bound waste foundry sand (SS-WFS) in construction is due to the presence of harmful residual sodium silicate film on the sand surface, which are detrimental to cement hydration. Based on previous research, this study proposes a pretreatment method using another industrial waste, calcium carbide slag (CCS), to effectively remove pollutants from sodium silicate-bounded waste foundry sand (SS-WFS). The feasibility of pretreated SS-WFS as an alternative to natural sand and optimal washing duration were investigated. The results demonstrate that pretreated SS-WFS exhibits promising potential as a substitute for 100% natural sand as a fine aggregate within the construction industry, while demonstrating comparable mechanical properties to those of natural sand mortar. The residual sodium silicate film on the surface of SS-WFS undergo secondary hydration, leading to the formation of hydration products with a low calcium-to-silicon ratio in interfacial transition zone. This enhances the mechanical properties of the mortar and improves its deformation characteristics. The optimal washing duration is determined to be 5 min with 1% CCS, and compared to RS-0, the mortar strength has increased by 70%. Extended washing duration may cause the depletion of beneficial components, such as active Si2O, from the sand surface.

Additive manufacturing of defect-free TiZrNbTa refractory high-entropy alloy with enhanced elastic isotropy via in-situ alloying of elemental powders

Laser powder-bed fusion (L-PBF) additive manufacturing presents ample opportunities to produce net-shape parts. The complex laser-powder interactions result in high cooling rates that often lead to unique microstructures and excellent mechanical properties. Refractory high-entropy alloys show great potential for high-temperature applications but are notoriously difficult to process by additive processes due to their sensitivity to cracking and defects, such as un-melted powders and keyholes. Here, we present a method based on a normalized model-based processing diagram to achieve a nearly defect-free TiZrNbTa alloy via in-situ alloying of elemental powders during L-PBF. Compared to its as-cast counterpart, the as-printed TiZrNbTa exhibits comparable mechanical properties but with enhanced elastic isotropy. This method has good potential for other refractory alloy systems based on in-situ alloying of elemental powders, thereby creating new opportunities to rapidly expand the collection of processable refractory materials via L-PBF.

Synthesis and comparative study of high Tg and colorless polyamide‐imides with different amide‐to‐imide ratio

AbstractColorless polyimide (CPI), a heat‐resistant polymer being widely used in optoelectrical devices, has attracted worldwide attention. Polyamide‐imides due to the incorporation of amide groups into the CPI chains enhance the polymer performance by improving the thermal dimensional stability and excellent mechanical properties without sacrificing the optical transparency. In this article, CPI films PI‐(1‐3) are synthesized from one‐step polymerization of 4,4′‐(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and cyclopentanone bis‐spironorbornane tetracarboxylic dianhydride (CpODA) with amide‐containing diamine N,N′‐(2,2′‐bis(trifluoromethyl)‐[1,1′‐biphenyl]‐4,4′‐diyl)bis(4‐aminobenzamide) (AB‐TFDB) and bis(trifluoromethyl)benzidine (TFDB). In comparison, by adjusting the ratio of imide and amide groups in the repeating unit, PI‐(4‐5) are prepared from copolymerization of terephthaloyl chloride (TPC), 6FDA, and CpODA with TFDB diamine. PI‐(1‐5) with 90% transmittance in the visible region tailored the excellent thermal and mechanical properties. Particularly, PI‐3 exhibited a high glass transition temperature of 412°C, a coefficient of thermal expansion of 20.8 ppm/K, a tensile strength of 128 MPa, and an elastic modulus of 5.4 GPa. The results also concluded that irrespective of the polyamide‐imide synthesis strategy, CPI films with similar amide‐to‐imide ratio in polymer chain demonstrated comparable optical, thermal, and mechanical properties.