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The progressive development of lightweight composites exhibiting desirable thermo‐mechanical properties is an area of growing interest, particularly with the phthalonitrile (PN) based composites, which have shown great potential. However, our understanding of the mechanical and thermal properties of the phenol‐containing phthalonitrile (PN75) resin composites often reveals limitations that make them less suitable for specific structural applications. In this work, we focused on enhancing the mechanical and thermal properties of the PN75 resin through the incorporation of the 4‐aminophthalonitrile (4‐APN), resulting in improved the curing behaviors and increased thermal stability. Our investigation of the short carbon fiber (SCF) and short glass fiber (SGF) reinforced PN75 resin composites revealed that the hybrid SCF/SGF‐based composites at 15 wt% SCF and 15 wt% SGF content exhibited an excellent tensile and the flexural strength. Additionally, the thermogravimetric analysis demonstrated maximum onset degradation and decomposition temperatures at this ratio compared with the neat resin, also we evaluated the interfacial adhesion properties of the SCF/SGF and the PN75 resin composites. These findings contribute to the advancement of polymer composite materials and expand their potential applications across various industries. [ABSTRACT FROM AUTHOR]

Simple synthesis and high performance are eternal pursuit for polymers. To lower the curing temperature, lower the melt viscosity and improve the processability of high performance phthalonitrile resins, a solvent‐free method was applied to synthesize three from different phenols. Their chemical structure was confirmed by FTIR and NMR spectra, the curing behavior was investigated by DSC and rheology. It was found that the polymerization of phthalonitrile groups could be effectively promoted by benzoxazine moieties and the curing temperature of phthalonitrile groups dropped to around 240°C. Consequently, owing to the high curing reactivity, polymers obtained at relatively low curing temperature possessed high crosslinking density and extremely high thermal stability. P‐apn‐200, which was cured at 200°C, showed 5 wt% weightloss temperature (Td5) of 472°C and char yield (Yc) of 75.77% at 800°C. Moreover, the polymers obtained after curing at 280°C showed superior dimensional stability, CN‐apn‐280 showed extremely low linear expansion coefficient (CTE) of 10.7 ppm/°C. And mP‐apn‐280 showed HR capacity of 3.99 J/g‧K, peak HRR of 4.0 W/K and total HR of 0.8 kJ/g. [ABSTRACT FROM AUTHOR]

Phthalontirile resins are renowned as the most heat‐resistant polymeric materials and exhibit exceptional performance under harsh conditions. Consequently, phthalonitrile thermosets offer the potential to substitute metals in hot parts, thereby broadening the operational limits of plastic materials in high‐tech applications. Given their unique combination of properties, phthalonitriles have garnered significant demand across sectors such as aerospace, automotive, electronics, and renewable energy. With industrial production and application of phthalonitriles recently initiated in several countries, questions regarding the sustainability of these materials have naturally arisen. Thermosetting materials, owing to their highly cross‐linked architecture, cannot be recycled, necessitating the adoption of synthetic methods utilizing bio‐feedstock raw materials and green protocols to mitigate their environmental impact. The present prospective review summarizes and analyzes the current state‐of‐the‐art in bio‐based phthalonitrile resins and discusses potential directions for research and development of new application areas, with a focus on the challenge of maintaining high‐performance levels during the transition to bio‐based raw materials. [ABSTRACT FROM AUTHOR]

Diglycidyl ether of bisphenol A crosslinking with glutaric anhydride is used to form the conventional "covalent adaptive network", polyether sulfone (PES) by coiling and aggregating on the adaptive network is used to significantly increase the uncured resin viscosity for improving the processability of epoxy resin, but inevitably affecting the curing reaction and dynamic transesterification reaction. This study investigates the crucial roles of PES in curing dynamics and stress relaxation behavior. The results indicate that although PES does not directly participate in the crosslinking reaction of polyester‐based epoxy vitrimers. Moreover, the isothermal curing studies reveal that the addition of PES can greatly bring forward the reaction rate peak from conversion α = 0.6 to α = 0.2, meaning that the curing mechanism transfers from chemical control to diffusion control. Dynamic property analysis shows that the addition of PES significantly accelerates stress relaxation, especially at lower temperatures, leading to low viscous flow activation energy Eτ and relatively insensitive stress relaxation behavior to temperature. Introducing PES into vitrimer resin greatly improves crosslinking density (2.31 × 10⁴ mol m−3), enhancing glass transition temperature (82.68 °C), tensile strength (68.66 MPa), and fracture toughness (6.25%). Additionally, the modified vitrimer resin exhibits satisfying shape memory performance and reprocessing capability. [ABSTRACT FROM AUTHOR]

The renewable and biosynthetic molecule, vanillin, was used in the preparation of a new phthalonitrile resin (PN), containing two phthalonitrile groups without pre‐modification of the vanillin structure. This PN resin was characterized thoroughly by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), nuclear magnetic resonance (NMR) spectroscopy, rheometry, Fourier transform infrared spectroscopy (FTIR), and single‐crystal X‐ray diffraction (XRD). The monomer exhibited excellent rheometric viscosities below 250 cP at processing temperatures and a good pot life. After complete curing, the PN polymer exhibited thermal stability above 500°C, a glass transition temperature (Tg) above the final postcure temperature of 380°C, and exceptional retention of structural integrity. These results highlight a vanillin‐derived PN resin is an excellent candidate for a variety of applications where high temperature and mechanical stability over a large temperature range are required. [ABSTRACT FROM AUTHOR]

ABSTRACT To explore the room‐temperature synthesis of metal phthalocyanines with unsaturated substituents, two zinc phthalocyanines with unsaturated alkoxy groups were synthesized in a reaction system composed of 4‐citronellol‐oxy‐phthalonitrile or 4‐geraniol‐oxy‐phthalonitrile, Zn(OAc)2⋅2H2O, DBU, and ethanol, at room temperature. The synthetic reactions lasted for 7 days and the yields of two phthalocyanine derivatives reached 21% and 18%, respectively, and they are inclined to protonation in a non‐coordinated organic solvent, for example, CHCl3. By the way, the phthalocyanine compounds with other metals, such as Cu, Ni, and Co, cannot be prepared. This work will provide preference for improving the synthetic method in the future, so as to synthesize many new phthalocyanine compounds in general laboratories. [ABSTRACT FROM AUTHOR]

Phthalonitrile monomer containing oxazine ring (BPS‐Ph) was synthesized using bisphenol‐S, aniline, paraformaldehyde, and 4‐nitrophthalonitrile via a two‐step method. The differential scanning calorimetry (DSC) data of the curing process of BPS‐Ph monomer indicates that the peak polymerization temperature of the cyan group is about 250°C and that confirms the promoting effect of oxazine ring on the curing reaction of phthalonitrile. The rheological data of E51/DDS containing BPS‐Ph indicates that the BPS‐Ph monomer also has promoting effect on the curing process. The activation energy was studied via the iso‐conversional method principle. The activation energy corresponding to the E51/DDS crosslinking reaction is 75.79 and 60.54 kJ mol−1, respectively, for pure E51/DDS and E51/DDS/BPS‐Ph. Moreover, the activation energy of the crosslinking of phthalhydrazine is 74.1 kJ mol−1 which is rather lower than that in pure BPS‐Ph, and that implies the synergistically catalytic effect of the oxazine ring and the amine. The addition of BPS‐Ph monomer significantly improves the thermal behaviors of the thermoset. The char yield in N2 atmosphere increased from 15.6% to 53.9% when adding 30% BPS‐Ph to the E51/DDS. Moreover, the peak weight loss temperature decreased from 407 to 385°C. The phase separation size of poly‐BPS‐Ph in E51/DDS is about tens to hundreds nanometers according to the atomic force microscopy (AFM) phase diagram. It is indicated that incorporation of phthalonitrile monomer containing oxazine ring into epoxy/amine system is an applicable and effective way to promote the thermal behavior of the thermoset. [ABSTRACT FROM AUTHOR]

Alzheimer's disease, is one of the irreversible neurodegenerative disorders among older people, causes behavior, memory, and thinking problems. This study aim is to synthesize of 4‐({8‐[3‐(dimethylamino)phenoxy]octyl}oxy)phthalonitrile, zinc(II) phthalocyanine and its water soluble derivative containing ({8‐[3‐(dimethylamino)phenoxy]octyl}oxy) substituents at the peripheral positions first time. To determine the potential of water soluble silicon(IV) and zinc(II) phthalocyanines for use in AD, spectrophotometric assays were performed to determine their acetylcholinesterase/butyrylcholinesterase inhibitory effects. In addition, their DNA nuclease properties were evaluated by agarose gel electrophoresis. The results showed that the compounds inhibited acetylcholinesterase/butyrylcholinesterase. They did not damage pBR322 plasmid DNA depending on time and concentration. As a result of the experiments, it is revealed that the compounds may be the potential for use as cholinesterase inhibitors, which is a promising approach for the treatment of Alzheimer's disease. [ABSTRACT FROM AUTHOR]

A low viscosity tetra‐functional cyclosiloxane epoxy resins (TGTS) is synthesized via a one‐step hydrosilylation reaction and cured separately with four different aromatic diamines to explore the reaction kinetics, network development, and thermal resistance. The hardeners used are 1,3‐phenylenediamine (PDA), diethyl toluene diamine (DETDA), 4,4‐diaminodiphenylmethane (DDM), and 1,3‐bis(4‐aminophenoxy) benzene, because of their availability and aromaticity. During cure with TGTS they all display autocatalytic behavior, but when compared to a traditional organic epoxy resin, diglycidyl ether of bisphenol A (DGEBA) cured with DDM however, the rate constants are about 3 times slower and less exothermic. The DETDA hardener in particular exhibits significantly slower rates of cure when compared to the other amines, being about an order of magnitude slower compared to the PDA curative. This is attributed to higher steric hindrance, compounded by reduced miscibility. The TGTS‐DDM carbon fiber composite displays the most thermal resistance after extended exposure to 220°C, producing the least mass loss and after combustion of about 12% compared to 20% for the DGEBA cured with DDM. The results presented here, illustrate that a tetrafunctional cyclic siloxane epoxy resin, can exhibit excellent processability, evidenced by very low viscosities and long gelation times, whilst also displaying excellent thermal resistance, whether at elevated temperature, or during combustion. [ABSTRACT FROM AUTHOR]

The phenolic‐type phthalonitrile (PN) was added to EP/DDM system in order to enhance the thermal and mechanical performance at high temperature. The influence of the added PN on the curing process of EP/DDM was studied via DSC and the activating energy (Eα) was calculated based on iso‐conversional method. The Eα values corresponding to EP/DDM crosslink reaction remained at about 60 kJ mol−1 while it dramatically increased to 68.2 kJ mol−1 when PN content reached 50 wt% (EP‐PN50). The Tg and char yield at 700°C in N2 increased from141°C, 25.7%, for the neat EP/DDM to 226°C, 68.7% for the EP‐PN50. The measured char yields of the cured blend were higher than the calculated values which implies the interaction between EP/DDM and polyphthalonitrile network. The tensile and bending tests were carried out at 413 K and the modulus of EP‐PN50 remains 2.3 Gpa. On the meantime, the cyano‐functionalized SiO2 (CNSiO2) was prepared to further promote the mechanical behaviors of this resin blend in high temperature. The contact angles of raw SiO2, KH560SiO2, CNSiO2 with EP‐PN50 are 59.3, 52.6, 49.7°, respectively, which confirms the better wettability of CNSiO2 to the EP/PN blend. Furthermore, the tensile and bending tests conducted at 413 K confirmed that the CNSiO2 was more efficient on enhancing the mechanical performance of this EP/DDM/PN system at high temperature. [ABSTRACT FROM AUTHOR]

Bismaleimide (BMI) resins is widely used in the aerospace field because of its excellent properties, but its poor toughness limits the possibility of its application in a wider range of fields. Therefore, a novel bio‐compound, 4‐(allyloxy)‐3‐methoxy‐N‐(3‐(triethoxysilyl)propyl)benzamide (AMTPM), was designed and synthesized from renewable vanillin, which has Schiff‐base structure, silico‐oxygen bond structure, and allyl structure. The chemical structure of AMTPM has been characterized and validated by Fourier transform infrared (FTIR) and hydrogen nuclear magnetic resonance (1H NMR). It was found that the addition of AMTPM can effectively promote the curing behavior of BD resins (BMI and diallyl bisphenol A (DBA) was mixed and cured at the ratio of 1:0.87, named BD resins). AMTPM can affect the thermal stability and improve the mechanical properties of BD‐AMTPM resins (BD resins modified by AMTPM in different addition), and the detailed discussion was conducted. With the increase of AMTPM content, the thermal stability of BD‐AMTPM resins was deteriorated while the residual weight percentage at 800°C (Yc) was increased. When the content of AMTPM reached 12 wt%, the results showed that Yc achieved the values at a magnitude of 37.57%. Meanwhile, the glass transition temperature (Tg) achieved 320°C. Among the BD‐AMTPM resins system, the BD‐6 wt% AMTPM has the best toughness and mechanical properties. The impact strength was increased by 29.2%, the tensile strength was increased by 22.1% and the elongation at break was increased by 44%. The fracture morphology of BD‐AMTPM resins was also studied by scanning electron microscopy (SEM) to support the mechanical experimental conclusions. This study provides a more environmentally friendly and convenient modifier, which is of great significance for expanding the application of bismaleimide resin. Highlights: A bio‐based modifying agent (AMTPM) was designed and successfully synthesized.AMTPM has both Si‐O and Schiff‐base structures.AMTPM can effectively improve the toughness of BD‐AMTPM resins through impact and tensile tests. [ABSTRACT FROM AUTHOR]

In this work, 3‐(pyrimidin‐2‐ylthio)phthalonitrile (n‐MP1), non‐peripherally 3‐(pyrimidin‐2‐ylthio) groups substituted Zn (II) phthalocyanine (n‐MP2), and its water soluble derivative (n‐MP3) have been firstly synthesized and characterized with spectral data. The interaction of the n‐MP3 complex with DNA was examined in vitro using UV–visible titrimetric and thermal denaturation assays and in silico by performing molecular docking studies. In addition, the antidiabetic activity of n‐MP3 was revealed spectroscopically by studying α‐glucosidase inhibition activities. The spectroscopic results indicated that n‐MP3 effectively binds to CT‐DNA with a Kb value of 2.0 × 105 M−1 and interacts with CT‐DNA via noncovalent binding mode. Besides, docking studies divulged that n‐MP3 exhibits a stronger binding tendency (BE: −10.64 kcal/mol) with DNA than the control compounds, (7.78 kcal/mol for ethidium bromide and −6.21 kcal/mol for cisplatin). Consequently, due to its strong DNA binding activity, n‐MP3 may be suitable for antimicrobial and anticancer applications after further toxicological test systems. Also, n‐MP3 complex inhibited the activity of α‐glucosidase with the IC50 value of 1.44 ± 0.08 μM, whereas IC50 value of acarbose was 237.24 ± 1.80 μM. Therefore, it can be said that n‐MP3 is a very effective α‐glucosidase inhibitor. [ABSTRACT FROM AUTHOR]

A multifunctional photoinitiator is presented, offering precise control over light‐induced polymerization initiation at 450 nm and material degradation at 365 nm. This is accomplished by covalently linking photoactive bis(acyl)phosphane oxide and photocleavable o‐nitrobenzyl ether moieties onto the surface of γ‐cyclodextrin. Upon degradation, the resulting linear polymers can be easily re‐dissolved in their corresponding monomer and re‐cured, exhibiting superior mechanical properties compared to the pristine material. Moreover, this photoinitiator enables the successful 3D printing of intricate and precise structures, representing a promising general strategy for developing recyclable photoresins for 3D printing applications. [ABSTRACT FROM AUTHOR]

To accomplish the potential of the New‐Space emerging era and facilitate scientific and commercial space exploration, the development of versatile, customized, and affordable space technologies is essential. 3D printing is established as a disruptive technology, enabling the production of complex and lightweight structures with enhanced performance. However, the harsh conditions of the space environment, including atomic oxygen (AO), extreme temperatures, and ionizing radiation, pose significant challenges to the durability and longevity of additive manufacturing‐produced polymers. Until now, there are no additive‐manufacturing polymeric materials that are specifically developed and qualified to withstand space hazards. To address these challenges, novel materials for additive manufacturing, composed of cyanate ester and extended‐bismaleimide are engineered to withstand the extreme conditions in space. The developed materials demonstrate superior thermo‐mechanical properties (flexural stress of 72 MPa and Tg = 260 °C), enhanced durability to AO erosion, ionizing radiation (10 years in orbit), and thermal stability (Td5% = 360 °C). Moreover, it is found that printing orientation governs the AO erosion, thus guiding optimal printing designs for enhanced durability to AO. The materials show improved performance, endurance, and reliability, thus contributing to the development of space‐qualified components and enabling the advancement of additive manufacturing for future space missions. [ABSTRACT FROM AUTHOR]

We introduce the first mechanochemical cyclotrimerization of nitriles, a facile strategy for synthesizing triazine‐containing molecules and materials, overcoming challenges related to carbonization and solubility. Conducting this solid‐state approach in a mixer ball mill with 4‐Methylbenzonitrile, we synthesize Tris(4‐methylphenyl)‐1,3,5‐triazine quantitatively in as little as 90 minutes. Just as fast, this mechanochemical method facilitates the synthesis of the covalent triazine framework CTF‐1 using 1,4 Dicyanobenzene. Material characterization confirms its porous (650 m2 g−1) and crystalline nature. Adjusting the induced mechanical energy allows control over the obtained stacking conformation of the resulting CTFs ‐ from a staggered AB arrangement to an eclipsed AA stacking conformation. Finally, a substrate scope demonstrates the versatility of this approach, successfully yielding various CTFs. [ABSTRACT FROM AUTHOR]

Epoxy-cyanate ester blends have attracted significant attention due to their unique synergistic properties and versatility in high-performance applications. However, achieving precise control over the phase-separated structures in these blends remains a challenge. In this work, we present a strategy for the preparation of epoxy-cyanate ester blends with high-performance through staged curing-induced phase separation. By incorporating a thermally latent catalyst, 4-ethyl-2-methylimidazole tetraphenylborate, into the epoxyanhydride-cyanate system, the reactivity differences of multiple curing reactions within the blend were precisely controlled, thereby inducing the formation of well-defined nanophase-separated structures. The polymer systems prepared exhibit high mechanical properties and heat resistance, primarily due to the interpenetrating networks created by the epoxy-anhydride-cyanate ester and the formation of nanodomains induced by the staged curing process. Furthermore, epoxy-cyanate ester blends demonstrate outstanding hygrothermal resistance due to the low polarity of the crosslinked network structure. This work provides new insights into regulating the microstructure of the thermosetting blends and expands the potential applications of these materials in fields requiring long-term durability and reliability. [ABSTRACT FROM AUTHOR]

As a high‐performance engineering plastic, the acrylonitrile‐butadiene‐styrene (ABS) resin possesses excellent heat resistance, chemical resistance, and toughness. However, there is a lack of flow properties of the ABS resin for many processing operations. With the aim of enhancing the flowability of the ABS resin, the effect of N,N′‐ethylene bis oleamide (EBO) as a new lubricant on the melt flow rate (MFR), torque value, and rheological behavior of the ABS resin was investigated. The result showed the MFR of the ABS resin with 2.0 wt% EBO was 22.1 g/10 min, which was improved by 49% compared with the pure ABS resin (14.8 g/10 min). The torque value of the ABS resin, including 2.0 wt% EBO (1.69 N m) was lower than that of the pure ABS resin (2.03 N m). The rheological study further indicated that EBO can reduce the complex viscosity of the ABS resin. The above results indicated that EBO was an effective lubricant for the ABS resin. A possible lubrication mechanism was proposed based on the consequences of the rotational rheometry, dynamic mechanical analysis, and molecular dynamics simulation. EBO decreased the entanglement density of the polystyrene‐acrylonitrile (SAN) molecular chains and increased the mobility of the SAN molecular chain segments. On the other hand, EBO increased the free space of motion of the SAN molecular chain segments due to the free‐volume effect thereby increasing the mean square displacement of the system. This work will provide a new way to achieve the high‐flow ABS resin and provide new insights into the lubrication mechanism of lubricants in the ABS resin thereby expanding the applications of the ABS resin. [ABSTRACT FROM AUTHOR]

In this study, we succesfully synthesized bio‐benzoxazine resins using eugenol, a bio‐based phenolic compound, in combination with three distinct functional amines: ethanamine, aniline, and hexane‐1,6‐diamine. Characterization of the resulting bio‐benzoxazine resins, namely E‐ea (eugenol, ethanamine), E‐a (eugenol, aniline), and E‐dh (eugenol, hexane‐1,6‐diamine), was performed through 1H NMR spectroscopy, FTIR spectroscopy, high‐resolution mass spectrometry, and elemental analysis. Thermal properties were investigated using thermogravimetric analysis (TGA) for both the eugenol‐derived bio‐benzoxazines (E‐ea, E‐a, E‐dh) and their corresponding polybenzoxazines (PE‐ea, PE‐a, PE‐dh). Notably, all eugenol‐based polybenzoxazines exhibited excellent thermal stability with very similar characteristics. Our findings suggest that the presence of allyl groups in eugenol promoted a more cross‐linked network structure compared to other functional groups on amines. As a result, eugenol‐derived bio‐benzoxazines demonstrated superior thermal properties, illustrated by their impressive char yields: PE‐ea; 45.6%, PE‐a; 45.1%, and PE‐dh; 44.1%. [ABSTRACT FROM AUTHOR]

In this work, a series of aldehyde‐substituted phthalocyanine compounds (1, 3, and 5) were prepared by the cyclotetramerization of the 4‐(5‐(diethylamino)‐2‐formylphenoxy) phthalonitrile (a) and the corresponding metal salts. Schiff base‐substituted phthalocyanines (2, 4, and 6) were derived from an aldehyde‐substituted phthalocyanine (1, 3, and 5) via the reaction of aldehyde‐substituted phthalocyanines with an amine reagent. The compounds that were obtained were characterized using FT‐IR, 1H {13C} NMR, UV–Vis, and MS spectra (a and 1–6). The inhibitory qualities of synthesized aldehyde and Schiff base‐substituted complexes against the enzymes butyrylcholinesterase (BChE) and acetylcholinesterase (AChE) were assessed. The majority of phthalocyanines exhibited strong enzyme‐inhibiting properties. Out of the six produced phthalocyanines, 3 and 4 displayed the most intriguing profiles as submicromolar selective AChE inhibitors (IC50 = 0.060 μM), whereas 1 demonstrated the most potent BChE inhibitor (IC50 = 0.024 μM). The aggregation studies of CoPcs, CuPcs, and ZnPcs (1–6) were also carried out in this work. [ABSTRACT FROM AUTHOR]

In this study, magnesium (II) phthalocyanines (2a, 3a) and their water‐soluble derivatives (2b, 3b) were synthesized via multistep reactions. The structures of these phthalocyanines were identified by FT‐IR, NMR, MALDI‐TOF, and UV–Vis spectroscopy. The ct‐DNA binding (UV–Vis absorption, competitive EB binding, and agarose electrophoresis studies) and supercoiled plasmid DNA nuclease properties (hydrolytic, photonuclease, oxidative nuclease, and photooxidative nuclease) of the water‐soluble compounds were investigated using different methods. The DNA binding constant (Kb) values of 2b and 3b were calculated as 8.45 ± (0.25) × 104 and 7.71 ± (0.13) × 104 M−1 at 25°C, respectively. The results showed that 2b had a stronger ct‐DNA binding effect than 3b according to Kb and r values. The DNA nuclease studies claimed that both compounds indicated photonuclease activity on plasmid DNA depending on the light dose. Additionally, 2b had a higher photonuclease capacity than 3b. All of these results showed that 2b had promising potential as a photosensitizer agent for photodynamic therapy. [ABSTRACT FROM AUTHOR]

In this study, chitosan (CS)‐based macromolecular synergistic antioxidant CS‐UC‐TDAA containing carbon–carbon double bond, hindered phenol, and aromatic secondary amine was prepared by using CS,10‐undecenoyl chloride (UC), p‐aminobenzoic acid (AA), 3,5‐di‐tert‐butyl‐2‐hydroxybenzaldehyde (TD) via esterification, Schiff base reaction, and acylation reaction. The molecular structure of CS‐UC‐TDAA was characterized by fourier transform infrared, 1H NMR, and elemental analysis. The effects of macromolecular synergistic antioxidant CS‐UC‐TDAA, small molecular antioxidant TDAA, commercial antioxidant 4020, and butylated hydroxytoluene (BHT) on the antiaging properties of styrene‐butadiene rubber (SBR)/SiO2 composites were systematically studied by accelerated thermo‐oxidative aging test, thermogravimetric (TG) analysis, and methanol Soxhlet extraction experiment. The experimental results show that CS‐UC‐TDAA has more outstanding thermo‐oxidative aging resistance, thermal stability, and solvent extraction resistance in SBR/SiO2 composites than TDAA, 4020, and BHT. The macromolecular synergistic antioxidant CS‐UC‐TDAA endows SBR/SiO2 composites with more durable antiaging performance, which is attributed to the synergistic antioxidant effect of its hindered phenol and aromatic secondary amine groups. Additionally, its resistance to migration and extraction is facilitated by the crosslinking of the carbon–carbon double bond with the rubber and its substantial molecular weight. [ABSTRACT FROM AUTHOR]

A phthalonitrile‐based bent shaped push‐pull dibenzodioxin was synthesized using an efficient and rapid monowave reactor‐assisted protocol in acceptable yields. When aqueous Fe3+ ion solution was added to the bent dibenzodioxin in dimethyl sulfoxide (DMSO), the fluorescence intensity of bent dibenzodioxin at 450 nm was quenched significantly. UV‐visible and fluorimetric measurements displayed high selectivity and sensitivity towards Fe3+ over other metal ions, with a low detection limit of 0.67 μM. Fluorimetric investigations like interference and reversibility test of bent‐dibenzodioxin with Fe3+ led to proving it as a potential canditate for chemosensor application. Job's plot showed 1 : 2 stoichiometry between the bent‐dibenzodioxin and Fe3+ ions respectively and it was proposed that the the binding of one of the Fe3+ ion is from the phenanthroline‐like bent pocket, featuring two oxygen atoms and the other Fe3+ ions binds with the two ortho‐dinitrile units of the bent‐dibenzodioxin. [ABSTRACT FROM AUTHOR]

A fast‐curing epoxy with improved mechanical properties, self‐healing and re‐processability was designed using a tailored Schiff based motif that offered dual covalent adaptable network (CAN) in epoxy. The designer motif is a dynamic hardener with both acetal linkage and a Schiff base motif in the same molecule which allowed us to gain a mechanistic insight into the evolving transient network in epoxy vitrimers. The dynamic hardener besides offering a cross‐linked network in epoxy can facilitate rapid exchange reactions, resulting in a material with high tensile strength (74 MPa), high glass transition temperature (121°C), and that can be re‐purposed through solvent induced degradation. The proposed dynamic curing agent is suitable to be employed as a coating material on substrates to ensure excellent self‐healing and re‐processability ensuring chemical recyclability. Few carbon fiber‐based laminates were prepared using the epoxy vitrimer and the recovery of CF post laminate preparation clearly demonstrates the closed‐loop circularity in epoxy vitrimers. Highlights: A unique dynamic curing agent is designed consisting of an aldehyde (salicylaldehyde) and an amine and acetal containing species (amino acetaldehyde dimethyl acetal).It facilitates imine and acetal exchange that can bond at temperatures <60°C and break at temperatures >105°C as evidenced by the vitrimer transition temperature.Epoxies show high tensile strength (74 MPa), exceptional Tg (121°C), fast stress relaxation and an activation energy of 96.2 KJ/mol.The imine‐acetal exchange system rendered the epoxies re‐processable, malleable and re‐usable. [ABSTRACT FROM AUTHOR]

A promising high temperature phthalonitrile (PN) resin composed of a polyetherketoneketone (PEKK) core bridged by two bisphenol A linkers and end capped with PN groups is presented. This PEKK‐PN resin was characterized via differential scanning calorimetry, thermogravimetric analysis, proton nuclear magnetic resonance spectroscopy, scanning electron microscopy, dynamic mechanical analysis, attenuated total reflection Fourier transform infrared, and rheometry. The PEKK‐PN resin was evaluated with two different compositions containing 1) 70:30 PEKK‐PN to bisphenol A PN (n = 0) and 2) pure PEKK‐PN. The 70:30 PEKK‐PN resin was mixed with bis[4‐(3‐aminophenoxy)phenyl]sulfone and exhibited a melt viscosity of 271 cP, much lower than the 657 cP viscosity of the pure PEKK‐PN mixture. Void‐free PEKK‐PN polymers were easily prepared by degassing and curing up to 380°C, resulting in fully crosslinked networks exhibiting thermal stability above 500°C and a 75% char yield. Additionally, the cured PEKK‐PN polymer samples displayed good mechanical integrity retaining 50% stiffness at 300°C. This combination of properties suggests these new PEKK‐PN resins are excellent materials for high temperature thermosets in composite applications. [ABSTRACT FROM AUTHOR]

Novel double DOPO‐grafted phthalonitrile flame retardant (DOPO‐DBAPh) has been successfully synthesized via solution reaction with amino‐substituted phthalonitrile monomer, bisphenol A, paraformaldehyde and 9, 10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) as initial materials. The molecular structure of DOPO‐DBAPh was investigated by FT‐IR and 1H‐NMR spectrum. Then, the DOPO‐DBAPh was added into epoxy (EP) to construct DOPO‐DBAPh/EP fire‐retarding composites by casting forming method. The effect of different proportions of DOPO‐DBAPh/EP fire‐retarding composites on the microstructure, thermal, mechanical, flame retardancy and combustion behavior was investigated. It was found that the DOPO‐DBAPh/EP fire‐retarding composites have a high glass transition temperature (Tg = 156∼179°C), and also have excellent thermal stability (T5% = 331.4∼365.4°C) and high flexural strength (96.1∼139.8 MPa). When DOPO‐DBAPh content is 5 wt%, the vertical burning grade and limiting oxygen index (LOI) of DOPO‐DBAPh/EP composites reached V‐0 and 29.6%, respectively. Furthermore, the cone calorimeter testing results showed that the addition of DOPO‐BAPh can obviously inhibit the decomposition rate of cured substance at high temperature and accelerated the formation of dense carbon layer. When DOPO‐BAPh content was 20 wt%, the total heat release rate (THR) and peak heat release rate (PHRR) of the DOPO‐DBAPh/EP fire‐retarding composites were decreased by 38.55% and 35.81% compared with that of cured EP. In a word, this work presents a good way for synthesizing economical and highly efficient flame retardant for use in the preparation of EP‐based fire‐retarding composites with excellent comprehensive performance. Highlights: Novel phosphorus‐nitrogen flame retardant (DOPO‐DBAPh) is developed.5 wt% DOPO‐DBAPh significantly improves the fire safety of EP resin.The DOPO‐DBAPh/EP composites exhibit good thermal and mechanical properties. [ABSTRACT FROM AUTHOR]

A series of poly(methylsilane arylether arylacetylene) (PSEA‐H) resins were synthesized from methyldichlorosilane and isomeric arylether arylacetylenes, and characterized by 1H‐NMR and FT‐IR spectroscopies. The effect of reactive Si‐H groups and the linking positions of benzene rings in the arylether arylacetylene units on the properties of the resins were investigated. The results show that PSEA‐H resins possess good processability with processing windows of over 80°C. The introduction of Si‐H groups reduces the curing temperatures for PSEA‐H resins and weakens the secondary relaxation for the cured PSEA‐H resins. The cured resins and T300 carbon fiber (T300CF) reinforced composites display high mechanical properties. The flexural strengths of a cured PSEA‐H resin and its T300CF composite at room temperature reach 64.2 and 426.5 MPa, respectively. The flexural properties depend on the linking positions of benzene rings. The cured PSEA‐H resins show excellent heat resistance with a temperature of 5% weight loss (Td5) above 500°C. [ABSTRACT FROM AUTHOR]

Two novel bio‐based benzoxazine monomers containing imide or amide group (HPIDD‐fa and HPBA‐fa) were synthesized from raw materials of benzoyl chloride/phthalic anhydride, tyramine, furfurylamine and paraformaldehyde via a two‐step reaction. Fourier transform infrared spectroscopy (FT‐IR), proton and carbon nuclear magnetic resonance (NMR) spectroscopies were performed to characterize the structures of the benzoxazine monomers. The curing behavior was investigated by using differential scanning calorimetry (DSC) and in situ FT‐IR, and the DSC results indicate that the peak curing temperatures of HPIDD‐fa and HPBA‐fa are centered at 248.5 and 230.1°C, respectively. In addition, thermogravimetric analysis (TGA) suggests that the newly developed bio‐based benzoxazine‐derived polybenzoxazines present excellent thermal stability with Td10 (temperature at 10% weight loss) of 385 and 368°C for poly(HPIDD‐fa) and poly(HPBA‐fa), respectively. The current investigation suggests that our newly obtained bio‐based thermosetting resins are promising materials for high‐tech applications. [ABSTRACT FROM AUTHOR]

In this study, a new di‐substituted phthalonitrile derivative namely 2‐[2‐{(3,5‐bis (trifluoromethyl) phenyl) ethynyl}‐4,5 dicyanophenyl] malonate was synthesized. The cycloteramerization of the resultant compound in the presence of the related metal salts resulted in a number of metal {M=Co, Mn, and Lu} phthalocyanines. The newly synthesized macromolecules were used for the functionalization of gold nanorods. To study the effect of modification and metal ion on the biological properties of the gold nanorods, the biological features of the phthalocyanines, phthalocyanine‐gold nanorod conjugates, and gold nanorods were examined by performing different biological approaches. In this study, the anti‐diabetic activities of fluorinated phthalocyanines and their gold nanorod conjugates were examined for the first time using pancreatic alpha‐amylase. The antioxidant activities of the studied nano/structures were analyzed using 2,2‐diphenyl‐1‐picrylhydrazil (DPPH) radical scavenging assay. Their antimicrobial and antimicrobial photodynamic therapy activities (APDT) were investigated, as well. They exhibited good DNA cleavage activities. The highest biofilm inhibition activities were obtained 97.49 and 91.53 % for 200 mg/L of nanoconjugate (7) against S. aureus and P. aeruginosa, respectively. All the studied biological candidates also displayed effective microbial cell viability inhibition activities against E. coli. [ABSTRACT FROM AUTHOR]

In this study, 4‐(2‐(4‐methylthiazol‐5‐yl) ethoxy) phthalonitrile (3) and zinc phthalocyanine complex (4) were synthesized and characterized. UV–vis and fluorescence spectra, aggregation, and fluorescence parameters of the zinc phthalocyanine compound were investigated. As biological properties, DPPH radical capture, antidiabetic, DNA cutting, antimicrobial, photodynamic antimicrobial, anti‐biofilm activities, and microbial cell viability parameters of the compounds were determined. The highest antioxidant activity was found as 62.80% at 100 mg/L concentration with compound 4, and compound 4 also showed the best antidiabetic activity as 65.17% at 400 mg/L concentration. In DNA cutting activity, it was determined that 3 and 4 cut DNA at all concentrations. For compounds 3–4, the minimum inhibitory concentration (MIC) values were found to be 32 and 16 mg/L for Enterococcus hirae and Enterococcus feacalis, respectively. The strongest MIC value of photodynamic antimicrobial activity was achieved as 4 mg/L for E. feacalis with 4. It was observed that both compounds inhibited the microbial viability activity of Escherichia coli by 100% at concentrations of 100 mg/L. Compound 4 inhibited biofilms of Pseudomonas aureginosa and Staphylococcus aureus as 92.48% and 98.56% at 50 mg/L concentration, respectively. [ABSTRACT FROM AUTHOR]

In this study, 1,5‐dihydroxynaphthalene moiety was introduced into a novolac resin structure, and propargyl ether naphthalene phenolic resin (PNPF) was synthesized by the Williamson etherification reaction, which improved the heat resistance of the resin and its processability. The structure of the PNPF resin was characterized using 1H NMR and FTIR analysis, and its processability, heat resistance, thermal expansion, and dielectric properties were evaluated. The results revealed that the addition of 1,5‐dihydroxylhine, increased the reaction activity of the PNPF resin, and decreased its initial curing temperature, with the resin exhibiting excellent processability. The cured resin also showed excellent heat resistance and thermomechanical properties. The 5% weight loss temperature (Td5) and glass transition temperature (Tg) of the resin increased to 437.61 and 362.04°C, respectively, while the coefficient of thermal expansion decreased from 60.17 to 44.52 ppm, with a reduction of 26.01%. Moreover, the dielectric constant and dielectric loss of the cured resin were 3.02 and 0.00239, respectively. [ABSTRACT FROM AUTHOR]

In this paper, the mechanical properties and thermal expansibility of cyanate resin (CE) copolymerization modified by epoxy resin (EP) under medium‐low temperature curing process were studied. The curing temperature of the modified resin was analyzed, and the results showed that the initial curing temperature of the copolymerization resin was reduced by 87°C compared with the blend resin and further reduced when dibutyltin‐dilaurate was used. The results of mechanical properties test showed that the tensile and bending strength of the modified resin were the highest, which were 55.5 and 97.3 MPa, respectively. The results of scanning electron microscopy showed that the modified resin with 80 wt% cyanate content had the coarsest tensile and bending sections, the largest number of fracture stripes and rich layers, so it had relatively better toughness. The linear thermal expansion coefficient (CTE) of modified resin was determined and the results showed that when the loading of cyanate was 80 wt%, the CTE of the modified resin reached the lowest, only 6.36 × 10−5°C−1. [ABSTRACT FROM AUTHOR]

This work concerns the thermal‐oxidative aging behavior of phthalonitrile thermosets and composites at 280–350°C. The easy‐to‐process resin containing bis(3‐[3,4‐dicyanophenoxy]phenyl)phenyl phosphate with APB as curing agent and the resin‐based composites post‐cured at 330°C, 350°C, and 375°C were studied. The phthalonitrile thermosets post‐cured at 330°C retained flexural strength of 77 MPa after 200 h of thermal aging at 280°C and 37 MPa (40%) after the same time at 300°C while the resins post‐cured at 350°C and 375°C lost over 80% of the flexural strength in these experiments. The same trend of faster oxidation of the samples post‐cured at higher temperatures was observed for the composites. For the first time, crosslinking reactions were observed during the aging, despite the aging temperatures being below the Tg of thermosets. Thus, the work shows a high long‐term thermal oxidative stability of the studied phthalonitrile resins at temperatures up to 300°C and fast destruction of the materials at 350°C despite the resin decomposition temperatures determined by dynamic TGA being over 500°C. The work has shown the negative effect of high‐temperature post‐curing on the operating properties of the phthalonitrile composites as constructive materials for long‐term application at elevated temperatures. Highlights: Oxidation of phthalonitrile thermoset occurs at temperatures over 300°C in air.Increase in post‐curing temperature decreases thermal oxidation resistance.Thermosets retained up to 77% of flexural strength after 200 h aging at 300°C.Composites retained over 90% of ILSS after 200 h of aging at 300°C. [ABSTRACT FROM AUTHOR]

A novel phthalazine‐based phthalonitrile resin was prepared by two different curing procedures. The phthalonitrile monomer, namely, 4,4′‐(((phthalazine‐1,4‐diylbis(oxy))bis(3,1‐phenylene))bis(oxy))diphthalonitrile (PDOP), was synthesized from the reaction of 1, 4‐dichloropthalazine, resorcinol, and 4‐nitrophthalonitrile. Its curing behavior and curing kinetics with 4‐(4‐aminophenoxy)phthalonitrile (APPH) were investigated by Differential Scanning Calorimetric (DSC). Isoconversional method based on Starink was applied to analyze the curing process of PDOP/APPH. The PDOP monomer exhibits a low melting point (89 °C) and a wide processing window (146 °C). The PDOP polymer mainly forms triazine, isoindoline, and phthalocyanine structure, as revealed by Fourier Transform Infrared (FTIR) spectroscopy, and its properties improved with the increase of post‐curing temperature and curing time. After post‐curing at 350 °C, the polymer has high storage modulus (3313 MPa), high glass‐transition temperature (380 °C), and outstanding thermal stability and thermal oxidation stability. [ABSTRACT FROM AUTHOR]

The effort to develop new anticancer agents with reduced side effects that can overcome chemotherapeutic resistance is one of the most important research areas of medicinal chemistry. In this study, the synthesis of compounds containing carbazole, one of such agents, and their effects on different types of cancer cell lines are presented. Carbazole compound containing alcohol group 1, its phthalonitrile derivative 2 and carbazole disubstituted axial silicon phthalocyanine compound 3 were synthesized for the first time. These compounds were evaluated for cell proliferation, cell cytotoxicity, cell morphology, cell migration, and cell apoptosis on brain cancer cells (A172 and C6), gynecological cancer cells (HeLa and A2780), colon cancer cells (SW620 and HT29), and normal cells (Beas2B, RPE, and HSF). The findings of the cytotoxic and anticancer effects of the compounds were evaluated together 1 was identified as a potent antiproliferative agent (IC50 values of 1 were 29.99–99.5 μg/mL for normal cells and 1.29–33.57 μg/mL for cancer cells) with mild cytotoxicity (% Cytotoxicity of 1 were 10.8–11.7 for normal cells and 13.8–15.9 for cancer cells). The action mechanism of the compounds was related to inhibiting cell migration and triggering cell apoptosis. Overall, 1 and 2 which appears to be an effective pharmaceutical agent, is a potential focus of further preclinical studies. [ABSTRACT FROM AUTHOR]

In this paper, we describe the synthesis and the (chir)optical properties of a novel series of circularly polarized luminescent emitters. These molecules involve a compact single benzene‐based donor‐acceptor fluorophore composed of two cyclic alkylamines as electron donors and a phthalonitrile moiety as electron acceptor linked to a configurationally stable BINOL acting as a chiral perturbation unit. These new compounds display fair quantum yields (up to 66%) with emission maxima around 500 nm in toluene solutions, and the study of their chiroptical properties has shown that the cyclic alkylamine's ring size affects significantly the luminescence dissymmetry factors, reaching 2.2 × 10−3 for the larger cyclic alkylamine moieties. [ABSTRACT FROM AUTHOR]

Cyanate esters are preferred resins for space composites based on excellent mechanical, thermal and dimensional properties. Yet, they are sensitive to co‐reactions with secondary constituents making compatibility a processing challenge. Anodized aluminum mandrels are commonly used for composite manufacturing but deleterious interactions with cyanate ester is not well understood. We investigate here the interaction of anodized aluminum mandrels with surrounding environments and its impact on cure, thermal stability and mechanical properties of M55J/RS3C composites. The uptake and diffusivity of environmental moisture in mandrels was determined gravimetrically and fit to a predictive Fickian model. Cured composite properties were evaluated and correlated with glass transition temperatures (Tg) by dynamic mechanical analysis (DMA), thermal stability by thermal gravimetric analysis (TGA), mechanical properties by flatwise tensile test, and the degradation depth profile by atomic force microscopy (AFM). Parallel to previous results for RS3C but more severe, the degradation penetrated up to 500 μm with reductions of 90°C in Tg, 100°C in thermal stability and 33% mass loss. The inorganic oxide surprisingly absorbs 10× more water at 10× higher rate than composite mandrel materials. The reported results show the anodization presents a unique hydrolysis risk when manufacturing cyanate ester composites so disciplined use and environmental conditioning should be considered when developing space structures. Highlights: Cyanate ester composites degraded by anodized mandrels for all conditions.Thermogram signals correlate to composite mechanical degradation.Composite degradation depth gradient determined by atomic force microscopy. [ABSTRACT FROM AUTHOR]

Diisooctyl 2,5‐furandicarboxylate (DEF), an ester derivative of 2,5‐furandicarboxylic acid (FDCA, a bio‐based platform chemical), resembles the physical and chemical properties of phthalates. Due to its excellent biodegradability, DEF is considered a safer alternative to the hazardous phthalate plasticizers. Although FDCA esters are currently mainly produced by chemical synthesis, the enzymatic synthesis of DEF is a green, promising alternative. The current study investigated the biosynthesis of DEF by Candida antarctica lipase B (CALB) immobilized on macroporous resins. Out of five macroporous resins (NKA‐9, LX‐1000EP, LX‐1000HA, XAD‐7HP, and XAD‐8) evaluated, the LX‐1000EP epoxy resin was identified as the best carrier for CALB, and the XAD‐7HP weakly polar resin was identified as the second best. The optimal immobilization conditions were as follows: CALB (500 μL) and LX‐1000EP (0.1 g) were incubated in phosphate butter (20 mM, pH 6.0) for 10 h at 35°C. The resulting immobilized CALB (EP‐CALB) showed an activity of 639 U/g in the hydrolysis of p‐nitrophenyl acetate, with an immobilization efficiency of 87.8% and an activity recovery rate of 56.4%. Using 0.02 g EP‐CALB as the catalyst in 10 mL toluene, and the molar ratio of 2,5‐dimethyl furanediformate (1 mmol/mL) and isooctyl alcohol (4 mmol/mL) that was 1:4, a DEF conversion rate of 91.3% was achieved after a 24‐h incubation at 50°C. EP‐CALB had similar thermal stability and organic solvent tolerance compared to Novozym 435, and both were superior to CALB immobilized on the XAD‐7HP resin. EP‐CALB also exhibited excellent operational stability, with a conversion rate of 52.6% after 10 repeated uses. EP‐CALB could be a promising alternative to Novozym 435 in the biomanufacturing of green and safe plasticizers such as DEF. [ABSTRACT FROM AUTHOR]

Bio‐manufactured eumelanin is investigated as a sustainable high‐char carbon additive for use with moldable high temperature resins. Blends of Bisphenol A poly‐ether‐ether‐ketone (PEEK)‐based phthalonitrile (PN) with 0–30 wt% melanin are prepared and characterized for their compositional, thermal, and mechanical properties. Although the char yield increases from 10 to 30 wt% melanin loading, the presence of melanin decreases the thermal stability compared to PN resin alone. Despite this, the melanin‐PN resins still maintain a very high char yield (>64%) up to 1000 °C under nitrogen. Rheology, thermal analysis, and mechanical measurements suggest off‐gassing of the melanin and increased crosslinking between the melanin and PN, leading to a lower flexural strength resin with higher additive loadings. Spectroscopic studies suggest possible interaction between melanin and PN during co‐curing, which ultimately can affect the processing and final properties of melanin‐additive composite materials. [ABSTRACT FROM AUTHOR]

Currently, there is limited literature on the introduction of naphthalene ring into phthalonitrile. In this study, we have successfully synthesized a novel phthalonitrile monomer (CPND) by incorporating a symmetrical rigid naphthalene ring structure, long flexible chains, and high-density cyano groups into the resin. The monomer is being cured with two different agents and procedures to investigate the impact of curing agent structure and ramp-up procedure on polymer properties. The structure of the monomer is being verified using nuclear magnetic resonance (NMR), infrared spectroscopy (FTIR), and wide-angle X-ray diffraction (WAXD). Differential scanning calorimetry (DSC) results reveal that the monomer has a low melting point of 111°C, making it easily processable. After mixing with the curing agent in the appropriate proportion, it has a calculated processing window of 129-135°C. Thermogravimetric analysis (TGA) reveals that the polymers exhibit remarkable thermal stability, with all T5% above 470°C under a nitrogen atmosphere. Additionally, the results obtained from dynamic mechanical analysis (DMA) indicate that the polymer, which is cured using APPH as a curing agent, displays favorable thermo-mechanical properties. The storage modulus of the polymers at room temperature is all higher than 3330 MPa, respectively. Moreover, the glass transition temperature is found to be higher than 400°C, signifying the excellent thermo-mechanical properties of the polymer. [ABSTRACT FROM AUTHOR]

In this study, molecular engineering and biomimetic principles are utilized to prepare highly effective nitrile‐functionalized pyrazine crosslinking units by exploiting pyrazine's unique nucleophilic strengthening mechanism and proton bonding ability. The curing behaviors of pyrazine‐2,3‐dicarbonitrile and phthalonitrile are investigated through model curing systems and molecular simulation. The results indicate that pyrazine‐2,3‐dicarbonitrile exhibits higher reactivity than phthalonitrile, promoted by amine. The cured products of pyrazine‐2,3‐dicarbonitrile predominantly comprise thermally stable azaisoindoline and azaphthalocyanine. This novel type of highly effective crosslinking unit, and the comprehended mechanism of action of pyrazine at the molecular level, significantly expand the application of pyrazine in materials science. [ABSTRACT FROM AUTHOR]

In this study, to improve the physico‐mechanical properties of epoxy thermosets, simultaneous curing of two resins with a stoichiometric amount of an aromatic amine hardener was investigated. The two resins used included the well‐known diglycidyl ether of bisphenol A (DGEBPA) with relatively rigid molecular structure and a diglycidyl ether derived from a popular polymer, polyethylene glycol (PEG), with loose molecular structure (DGEPEG). DGEPEG was used in amounts of 10 and 25 mol% in the resin mixture. A single‐resin curing process, including only DGEBA, was also examined. Before isothermal curing, differential scanning calorimetry (DSC) was used to determine the position of the curing exotherm. To ensure the completion of the curing processes, infra‐red (IR) and DSC techniques were performed on both simultaneously‐cured thermosets and the control thermoset. The thermogravimetric analysis (TGA) of the prepared thermosets showed that the addition of DGEPEG resin in the curing process of DGEBA resin has no significant effect on reducing the thermal resistance of the thermoset. In addition, the storage moduli (E′) and the damping coefficients (tan δ) were measured by dynamic mechanical analysis (DMA). As the mole percentage of DGEPEG resin increased, the rapid drop in the E′ value and the α‐relaxation, which is a measure of the glass transition (Tg), occurred at lower temperatures. [ABSTRACT FROM AUTHOR]

This study focuses on the heating stage of the rotational molding process. When the mold wall reaches the tacky temperature, free flowing powder starts to adhere, melt, and sinter. In this work, a new modeling strategy is proposed. Compared with the models found in the literature, the model combines the use of a tacky temperature for the adherence of powder, changing boundary conditions, and thermophysical properties as function of temperature and the degree of sintering. The changing boundary conditions are introduced to take into account both wall to air and wall to powder contact. The calculation of the temperature evolution is done by applying the thermal finite difference principle to elements with a fixed polymer mass. The modeling of a uniaxial rotating cylinder is chosen as a case study. The validation is done for an amorphous polycarbonate resin. The performance of the model is evaluated not only by the comparison of temperature‐time data as is the case in most literature, but also by the decrease in free flowing powder weight as function of time, visual data from an in‐mold looking camera, and through thickness analysis of the molded pieces at various moments in the heating process. [ABSTRACT FROM AUTHOR]

Multitask star‐shaped oligoaniline (S‐TAH) was synthesized using microwave irradiation in three steps: preparation of phthalic acid‐ capped tetra‐aniline (as the arm), synthesis of a tetrafunctional biobased core, and subsequently, coupling arms to the core, using a divergent approach. A biobased core was synthesized through a direct condensation reaction of pentaerythritol, with l‐lactic acid. The chemical structures were extensively characterized using Fourier‐transform infrared and proton nuclear magnetic resonance spectroscopy. The performance of S‐TAH, as a multitask hardener for bisphenol A‐based epoxy resin (EP), was evaluated using differential scanning calorimetry, thermal gravimetric analysis, dynamic thermomechanical analyses (DMTA), and four‐prob conductometry. Peaks of cure exotherms for S‐TAH/EP (1:1) systems appear at 135°C with a tail‐like peak around 175°C. Compared to conventional amine‐cured EP, the thermal stability of the S‐TAH/EP cured was significantly higher, that is, ~ 40°C enhancement in half weight loss temperature (T50). A three‐fold improvement in char yield was observed. From DMTA, the material cured with S‐TAH displays representative storage moduli in glassy (9.4 GPa) and rubbery (5.2 GPa) states reflecting a uniform network and viscoelastic behavior. The electrical conductivities (σ) of the pure S‐TAH and the epoxy systems cured with S‐TAH/EP are 4.3 × 10−4, and 2.65 × 10−4, respectively. T star‐shaped oligoaniline is a promising multitask hardener—functioning as hardener, thermal stabilizer, electrically conductive and toughening agents—which can be versatilely applied in thermal resistance anticorrosive coatings and conductive adhesives. [ABSTRACT FROM AUTHOR]

The curing kinetic model of epoxy resin is crucial for understanding reaction mechanism and accurately describing curing behavior of fiber reinforced polymer composites. In the investigations related to kinetic models of epoxy, much attention is payed to the curing characterizations of modified or mixed materials for the desired field of application in the case that the initial curing degree for calculating kinetic parameters is generally constant. In this paper, a new method by specifying the initial curing degree for kinetic parameters is developed to improve the accuracy of fitting models based on the resin systems and methods for activation energy. The curing kinetics of resin systems including Epoxy 4330, Epoxy 5212, and diglycidyl ether pentaerythritol vanillin diacetal‐bisphenol‐A epoxy resin‐4,4′‐diaminodiphenyl sulfone (DEPVD‐E51‐DDS) are examined utilizing differential scanning calorimetric technique at five different heating rates. Additionally, Kissinger, Starink, and Friedman methods, and piecewise models are adopted to fit the experimental data. The predictions from fitting models using different initial curing degrees are subsequently compared with experimental data. It is concluded that the utilization of initial curing degree promotes the accuracy of fitting models. [ABSTRACT FROM AUTHOR]

The design of a versatile alkyne‐bearing derivative of the donor‐acceptor fluorophore 2,4,5,6‐tetrakis(9H‐carbazol‐9‐yl) isophthalonitrile (4CzIPN) suitable for further targeted modifications by copper‐catalysed Azide Alkyne Cycloaddition (CuAAC) is reported. The newly synthesised photoredox catalyst notably exhibits analogously unique photoelectronic and steric features as the well‐established carbazolyl dicyanobenzene motif and performs equally in a C−C‐Coupling model reaction. Furthermore, the variability of this donor‐acceptor system was demonstrated by the generation of a library of fourteen photoredox catalysts with electron‐withdrawing and ‐donating groups as well as residues with high steric demands in one simple and selective CuAAC reaction. The modified catalysts feature a broad scope of reducing and oxidising powers in their excited states (span of reducing powers over more than 1 V) and were also successfully applied in the photoredox and nickel‐catalysed decarboxylative cross coupling model reaction. This work represents a method to overcome the limitations in the flexibility of metal‐free donor‐acceptor fluorophores required for the targeted application in organic synthesis and paves the way for the design of customised catalysts with multiple functionalities. [ABSTRACT FROM AUTHOR]

This work investigates the influence of methylhexahydrophthalic anhydride (MHHPA) on the properties of phthalic anhydride‐based unsaturated polyester resin (PA‐based UPR) when PA is replaced by MHHPA with different PA/MHHPA mole ratios, ranging from 100/0 to 0/100. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) are used to study the chemical structure, curing process and mechanical properties of the resins, showing the successful incorporation of MHHPA into the structure of UPRs with superior properties, compare to PA‐based UPRs. In particular, the addition of MHHPA significantly lowers the acidity by up to 28% and promotes the curing reaction, reducing the enthalpy of the reaction by 2.5 times, and shortens the curing time by up to 40%. This incorporation also increases the gel content up to 99.9%, thereby increasing the crosslinking between the polyester chains and improving the rigidity of UPRs. In addition, the glass‐transition temperature of the polymer increases approximately 78%, which can improve the working temperature of the MHHPA‐modified UPRs. The electrical properties of the resins containing MHHPA reveal better insulating performance in comparison with the PA‐based UPR. These findings demonstrate great potentials of the MHHPA‐modified UPRs for various applications, especially in outdoor environments. [ABSTRACT FROM AUTHOR]

The curing of Lonza Primaset PT‐30 novolac cyanate ester resin and EPON 826 bisphenol‐A diglycidyl ether were investigated using convective thermal heating and variable frequency microwave (VFM) heating. The addition of 1 part per hundred reduced graphene oxide (r‐GO) to PT‐30 novolac cyanate ester increased the VFM cure rate compared to thermal heating. Curing it at 160°C for 240 min with VFM heating resulted in a 55% degree of cure compared to a 26% degree of cure with thermal heating. This observed VFM rate enhancement is due to selective microwave heating of the r‐GO particles in the resin resulting in increased r‐GO catalytic activity toward cyanate ester curing. It is both a thermal and catalytic effect, the latter of which is absent when r‐GO is added to a bisphenol‐A diglycidyl ether resin with o‐phenylenediamine hardener. Impurities present in the PT‐30 matrix do not appear to contribute to its overall cure kinetics, nor do they participate in the observed VFM rate enhancement. [ABSTRACT FROM AUTHOR]

This study reports the synthesis of three silicon phthalocyanines (SiPc1–3) bearing 2‐dimethylaminoethoxy, 2‐[2‐(dimethylamino)ethoxy]ethoxy, or 2‐{2‐[2‐(dimethylamino)ethoxy]ethoxy}ethoxy on axial positions. Also, their quaternized derivatives (SiPcQ1–3) were prepared. The effect of ligand length on the biological features of water‐soluble silicon phthalocyanines (SiPcQ1–3) was investigated. The highest antimicrobial activity was obtained 32 μg/mL for SiPcQ1 against double‐distilled water, E. hirae, and E. faecalis. The growth inhibition percentages of compounds SiPcQ1–3 were obtained 100 %, 100 %, and 85.14 %, respectively. The highest biofilm inhibition activity was obtained 86.16 % for 250 mg/L SiPcQ3 against S. aureus. The E. coli growth inhibition activities of 50 mg/L compounds SiPcQ1–3 ranged from 60.17 % to 87.53 % and their activities increased (73.46 %–95.37 %) by the enhancement of the concentration. The E. coli viability inhibition activities of SiPcQ1–3 were concentration‐dependent. The DNA cleavage and binding properties of SiPcQ1–3 were studied using pBR322 DNA and CT‐DNA, respectively. Besides, the toxicity of SiPcQ1–3 was examined against the human colon cancer cell line (DLD‐1). The IC50 values of compounds (SiPcQ1–3) were obtained between 10.12 and 27.06 μM in the dark, however, these values were calculated between 12.32 and 22.17 μM under the light. SiPcQ3 exhibited the highest in vitro anticancer activity against the tested cell. [ABSTRACT FROM AUTHOR]

This study describes the synthesis and characterization of peripherally and non‐peripherally substituted copper(II) and cobalt(II) phthalocyanines bearing tetraethyleneglycol monomethyl ether chains. In addition, the metal‐free and zinc(II) phthalocyanine derivatives were prepared according to the referred procedure. All newly synthesized phthalocyanines were characterized using some spectroscopic techniques such as elemental analysis and fourier transform infrared, ultraviolet‐visible, and mass spectroscopies. The effects of solvent type and concentration on aggregation properties of phthalocyanines were studied, as well. The biological activities of a series of these peripherally and non‐peripherally tetra‐substituted phthalocyanines were investigated. The effects of the central metal ion and the position of the substituent on biological activities of phthalocyanines were also compared. When the antioxidant activities of the synthesized molecules were evaluated by the 2,2‐diphenyl‐1‐picrylhydrazyl method, 1,8/11,15/18,22/25‐tetrakis[2‐(2‐(2‐(2‐methoxyethoxy)ethoxy)ethoxy)ethoxy]phthalocyaninatocobalt(II) (63.17±0.012 %) showed the highest activity. The highest reducing power activity was obtained with the 2,9/10,16/17,23/24‐tetrakis[2‐(2‐(2‐(2‐methoxyethoxy)ethoxy)ethoxy)ethoxy]phthalocyaninatozinc(II) molecule. In the antibacterial activity studies using the disc diffusion method, 2,9/10,16/17,23/24‐tetrakis[2‐(2‐(2‐(2‐methoxyethoxy) ethoxy)ethoxy)ethoxy]phthalocyaninatocopper(II) exhibited the highest inhibition activity on both gram negative (18±0.23 mm) and gram positive (23±0.07 mm) strains. On the other hand, 2,9/10,16/17,23/24‐tetrakis[2‐(2‐(2‐(2‐methoxyethoxy)ethoxy) ethoxy)ethoxy]phthalocyaninatozinc(II) and 1,8/11,15/18,22/25‐tetrakis[2‐(2‐(2‐(2‐methoxyethoxy)ethoxy)ethoxy)ethoxy]phthalo‐cyaninatozinc(II) compounds presented hemolytic activity against sheep blood in the hemolytic activity studies. The results confirmed that the synthesized molecules demonstrated average antioxidant activity compared to standard antioxidants. 2,9/10,16/17,23/24‐Tetrakis[2‐(2‐(2‐(2‐methoxyethoxy)ethoxy)ethoxy)ethoxy]phthalo‐cyaninatocopper(II), 2,9/10,16/17,23/24‐tetrakis[2‐(2‐(2‐(2‐methoxy ethoxy)ethoxy)ethoxy)ethoxy]phthalocyaninatozinc(II) and 1,8/11, 15/18,22/25‐tetrakis[2‐(2‐(2‐(2‐methoxyethoxy)ethoxy)ethoxy) ethoxy]phthalocyaninatozinc(II) complexes could remarkably inhibit S. aureus and CuPc‐1 complex E. coli growth. [ABSTRACT FROM AUTHOR]

The goal of this work is to study the influence of the type of vulcanization accelerator and the quantitative composition of the curing system on the cure characteristics, morphology of elastomer network, crosslink density and physico‐chemical properties of acrylonitrile‐butadiene rubber (NBR) composites. Sulfur curing systems are investigated, which consist of various types of accelerators, that is, sulfenamide, guanidine and thiuram, applied in various proportions to sulfur. The type of accelerator and the sulfur/accelerator ratio significantly affect both the cure rate and the structure and number of crosslinks resulting from the vulcanization. The highest cure rate and the lowest content of polysulfidic crosslinks are exhibited by rubber composites with efficient (EV) curing systems due to the highest content of accelerators compared to semi‐efficient (SEV) and conventional (CV) systems. The structure of crosslinks strongly affect tensile properties and hardness of the vulcanizates as well as their solvent resistance, thermal stability and resistance to thermo‐oxidative aging. [ABSTRACT FROM AUTHOR]