To improve the dispersion of graphene oxide (GO) nanosheets in sizing agent and to enhance the interfacial adhesion between GO and epoxy, GO nanosheets were chemically modified with cyanuric chloride (TCT) and diethylenetriamine (DETA). The functionalized GO (i.e. GO-TCT-DETA) with different contents was introduced into the carbon fiber (CF) interface by sizing process. The uniform distribution of GO sheets on CF surface and the enhancement of surface roughness were obtained. Moreover, significant enhancements (i.e., 104.2%, 100.2%, and 78.3%) of interfacial shear strength (IFSS), interlaminar shear strength (ILSS), and flexural properties were achieved in the composites with only 1.0 wt% GO-TCT-DETA sheets introduced in the fiber sizing. The GO-TCT-DETA in the interface region enhanced the stress being transferred effectively and the local stress concentrations being relieved. This study indicates that the utilization of functionalized GO is one of the alternative approaches for controlling the fiber-matrix interface and improving the mechanical properties of CF epoxy composites.

Reinforcing carbon fiber epoxy composites with triazine derivatives functionalized graphene oxide modified sizing agent

The effective control of crystallinity of covalent organic frameworks (COFs) and the optimization of their performances related to the crystallinity have been considered as big challenges. COFs bearing flexible building blocks (FBBs) generally own larger lattice sizes and broader monomer sources, which may endow them with unprecedented application values. Herein, we report the oriented synthesis of a series of two-dimensional (2D) COFs from FBBs with different content of intralayer hydrogen bonds. Studies of H-bonding effects on the crystallinity and adsorption properties indicate that partial structure of the COFs is “locked” by the H-bonding interaction, which consequently improves their microscopic order degree and crystallinity. Thus, the regulation of crystallinity can be effectively realized by controlling the content of hydrogen bonds in COFs. Impressively, the as-prepared COFs show excellent and reversible adsorption performance for volatile iodine with capacities up to 543 wt %, much higher than ...

Mechanistic Insight into Hydrogen-Bond-Controlled Crystallinity and Adsorption Property of Covalent Organic Frameworks from Flexible Building Blocks

Enhanced interfacial interactions of carbon fiber reinforced PEEK composites by regulating PEI and graphene oxide complex sizing at the interface

A novel strategy to simultaneously electrochemically prepare and functionalize graphene with a multifunctional flame retardant

Porous organic frameworks (POFs), a general term for covalent-organic frameworks (COFs), covalent triazine frameworks (CTFs), porous aromatic frameworks (PAFs), etc., are constructed from organic building monomers with strong covalent bonds and have generated great interest among researchers. The remarkable features, such as large surface areas, permanent porosity, high thermal and chemical stability, and convenient functionalization, promote the great potential of POFs in diverse applications. A critical overview of the important development in the design and synthesis of COFs, CTFs, and PAFs is provided and their state-of-the-art applications in analytical chemistry are discussed. POFs and their functional composites have been explored as advanced materials in "turn-off" or "turn-on" fluorescence detection and novel stationary phases for chromatographic separation, as well as a promising adsorbent for sample preparation methods. In addition, the prospects for the synthesis and utilization of POFs in analytical chemistry are also presented. These prospects can offer an outlook and reference for further study of the applications of POFs.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/advs.201801116

Porous Organic Frameworks: Advanced Materials in Analytical Chemistry

The invention discloses a compatilizer for a carbon fiber reinforced phthalazinone copolyether sulfone commixed resin-based composite material as well as a preparation method and an application and belongs to the technical field of advanced composite material science. The compatilizer is prepared from double halogen monomers and a third active monomer through a nucleophilic condensation polymerization reaction. The compatilizer has an excellent modification effect on the carbon fiber reinforced phthalazinone copolyether sulfone commixed resin-based composite material. The invention particularly relates to a method for optimizing and improving overall properties of composite materials by adjusting and controlling the types and the number of structure units of the third active monomer in the compatilizer and the ratio of the compatilizer to composite material substrate resin. According to the compatilizer, the interface properties of the composite material are regulated and controlled by adjusting the content of the structure units of the third active monomer on the main molecular chain of the compatilizer and the content of the compatilizer in the composite material, and furthermore the mechanical properties, the thermal resistance grade and the environment stability of the composite material are optimized and regulated. The compatilizer has great practical significances for development and popularization of carbon fiber reinforced high-performance thermoplastic composite materials.

Compatilizer for carbon fiber reinforced phthalazinone copolyether sulfone commixed resin-based composite material as well as preparation method and application

Di-halogen monomer structures play crucial roles in determining the combined properties of high-performance poly(aryl ether)s for microelectronic applications. In order to disclose such relationship in detail, 9,9-bis(4-hydroxyphenyl) fluorene (BHF) was utilized to polymerize with various di-halogen monomers, bearing phenyl-1,3,5-triazine, ketone, sulfone, nitrile, diketone moieties. Through solution nucleophilic substitution polymeri-zation, a series of linear poly(fluorenyl aryl ether) (PFEX) was prepared. FTIR, 1H-NMR were resorted to confirm the polymer structure. PFEXs with high molecular weight exhibited a combination of excellent properties. Poly(fluorenyl aryl ether phenyl-s-triazine) (PFEP) and poly(fluorenyl aryl ether sulfone) (PFES) showed low dielectric constant of 2.59 and 2.43, respectively. Representatively, PFEP with Td5% value as high as 561 °C and Tg up to 302 °C showed high light transmittance (86.94%), and tensile strength up to 91 MPa. Based on free volume calculation by molecular dynamics method, it was found that rigid and bulky structures, such as phenyl-1,3,5-triazine and sulfone groups, were proved to be beneficial for polymer thermal performance along with the dielectric property and light transparence. Robust polar group, for instance nitrile group, contributed more to thermal resistance, however, negatively affected the dielectric property. This work provide commendable suggestions for di-halogen monomer selection for future low-dielectric poly(aryl ether) developments. 

Effect of di‐halogen monomers embraced in main chain of low‐dielectric colorless fluorene‐based poly(aryl ether)s on their performance

The invention provides a bisphthalonitrile resin fiber enhanced material with a triphenyl sym-triazine structure and a preparation method thereof, and belongs to the technical field of polymer materials. The enhanced resin consists of glue and fiber materials according to a mass ratio of (1.0 to 99.9):100; the glue comprises bisphthalonitrile resin of the triphenyl sym-triazine structure, has the general molecular formula shown by the formula I, and also comprises the following ingredients of curing agents, curing accelerating agents and filling materials. The preparation method of the bisphthalonitrile resin fiber enhanced material comprises a glue preparation step, a glue soaking step, a forming step and a curing step. The prepared fiber enhanced material has certain structure intensity and also has a high heat-resistant grade.

Bisphthalonitrile resin fiber enhanced material with triphenyl sym-triazine structure and preparation method thereof

The invention provides poly(phthalazinone ether) provided with a composite coating on the surface and a preparation method of the poly(phthalazinone ether) and belongs to the technical field of polymer science. The composite coating of the poly(phthalazinone ether) provided with the composite coating on the surface comprises a polydopamine layer and a bone-like apatite layer, wherein the polydopamine layer comprises a polydopamine layer not modified with a phosphoric acid functional group and a polydopamine layer modified with the phosphoric acid functional group, and the thickness of the polydopamine layer is smaller than 1 mu m; the bone-like apatite layer contains Ca and P, and the thickness is smaller than 1 mu m. The preparation method of the poly(phthalazinone ether) comprises steps of surface deposition of polydopamine and biomimetic mineralization of bone-like apatite, adopts a simple process, and is low in cost. The bone-like apatite layer can improve properties including surface hydrophilicity and biocompatibility of polyarylether.

Poly(phthalazinone ether) provided with composite coating on surface and preparation method of poly(phthalazinone ether)

Modern microelectronics devices urgently request low dielectric constant materials with commendable mechanical properties. Novel fluorinated poly(aryl ether)s (FPPEs) were prepared by traditional polycondensation of 4-(4-Hydroxylphenyl)(2H)-phthalazin-1-one (DHPZ), Bisphenol AF (BAF) and Decafluorobiphenyl (DFB) to study bulky phthalazinone effects on mechanical and dielectric behavior of polymers. After the introduction of phthalazinone moieties, FPPEs showed excellent solubility to readily solve in many organic solvents like NMP, DMAc, CHCl3, and THF. Simultaneously, they exhibited relatively high glass transition temperatures (Tgs) from 180 °C to 294 °C, increasing with the content of phthalazinone groups. The FPPEs still possessed excellent thermal stability with decomposition temperature up to 514 °C and char yield at 800 °C as high as 56% under nitrogen atmosphere. FPPE films showed good mechanical strength with tensile stress higher than 68 MPa and modulus surpassing 10.8 MPa, also increasing with phthalazinone concentration. The dielectric property of FPPEs was investigated with impedance analyzer. FPPE8020 and FPPE 6040 showed dielectric constant from 3.10 to 3.30 and dielectric loss of 0.005–0.008 under a large frequency range of 0.02–60 GHz. The phthalazinone moieties mainly contributed to the decrease of dielectric constant. The results evidently suggest FPPEs as commendable candidate for those high-tech electronic applications.

Lishuai Zong

Papers

Compatilizer for carbon fiber reinforced phthalazinone copolyether sulfone commixed resin-based composite material as well as preparation method and application

Effect of di‐halogen monomers embraced in main chain of low‐dielectric colorless fluorene‐based poly(aryl ether)s on their performance

Bisphthalonitrile resin fiber enhanced material with triphenyl sym-triazine structure and preparation method thereof

Poly(phthalazinone ether) provided with composite coating on surface and preparation method of poly(phthalazinone ether)

Preparation and properties of multi-fluorinated N-heterocycle-containing poly(phthalazinone ether)s with high strength and low dielectric constant