65632-78-2Relevant academic research and scientific papers
Synthesis of a smart bisbenzoxazine with combined advantages of bismaleimide and benzoxazine resins and its unexpected formation of very high performance cross-linked polybenzoxazole
Hao, Boran,Ishida, Hatsuo,Zhang, Kan
, (2021)
We report a bisbenzoxazine thermosetting system, oHPMI-ddm, which shows combined advantages of both bismaleimide and benzoxazine resins. The chemical structure of oHPMI-ddm has been identified by FT-IR and NMR spectroscopies, and its polymerization processes have been investigated using differential scanning calorimetry (DSC) and in situ FT-IR. The resulting polybenzoxazine derived from this thermosetting system exhibits significantly higher thermal stability than thermosets polymerized from the commercialized 4,4′-diaminodiphenylmethane based bisbenzoxazine (PH-ddm) and bismaleimide (DDM-BMI). This newly obtained benzoxazine also shows a unique structural thermal rearrangement in comparison to the cross-linked polybenzoxazole in a similar manner as other reported smart ortho-benzoxazines, although it has no obvious hydrogen bond forming group and cannot form 5- or 6-membered intramolecular interaction. Such conversion from polybenzoxazine to polybenzoxazole has been confirmed by both in situ FT-IR and solid state 13C NMR. Furthermore, the finally obtained cross-linked polybenzoxazole possesses outstanding properties of high thermal stability, excellent flame retardancy and low dielectric constant, indicating great potential for high performance material applications.
Dibenzoxazine monomer containing ortho-position maleimide groups and preparation method thereof
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Paragraph 0028; 0029, (2017/08/27)
The invention discloses a dibenzoxazine monomer containing ortho-position maleimide groups and a preparation method thereof. The molecular formula is show in the following picture, wherein R1 is any one of following structures. The introduced ortho-position maleimide groups weaken the rigidity of molecules, effectively shorten the time for synthesis of benzoxazine and improve the machinability of benzoxazine resin. In addition, except for oxazine ring curing cross-linking of dibenzoxazine, the maleimide groups at the two ends of a molecule further can carry out secondary bi-crosslinking, and therefore the thermal stability of the resin is greatly improved. The preparation technology is simple, the comprehensive performance of the resin is excellent, and the dibenzoxazine monomer is suitable for matrix resin of high-performance compound materials.
O-maleimide mono-functionalized benzoxazine monomer and preparation method thereof
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Paragraph 0030; 0031; 0032, (2017/08/23)
The invention discloses an o-maleimide mono-functionalized benzoxazine monomer and a preparation method thereof. A molecular formula of the monomer is as follows (shown in the description); the molecular formula is one of the following structures shown in the description. A maleimide radical is introduced into an ortho-position of benzoxazine, and the reaction synthesis time is effectively shortened; moreover, when the benzoxazine is cured, oxazine ring is subjected to opening-ring curing and cross-linking; the maleimide radical can also be subjected to secondary cross-linking to obtain a more dense double-cross-linking network structure, so that the thermal stability of resin is greatly improved, and the processability of the resin is also improved.
Design and synthesis of a novel DNA-encoded chemical library using Diels-Alder cycloadditions
Buller, Fabian,Mannocci, Luca,Zhang, Yixin,Dumelin, Christoph E.,Scheuermann, Joerg,Neri, Dario
supporting information; experimental part, p. 5926 - 5931 (2009/05/31)
DNA-encoded chemical libraries are increasingly being employed for the identification of binding molecules to protein targets of pharmaceutical relevance. Here, we describe the synthesis and characterization of a DNA-encoded chemical library, consisting of 4000 compounds generated by Diels-Alder cycloaddition reactions. The compounds were encoded with unique DNA fragments which were generated through a stepwise assembly process and serve as amplifiable bar codes for the identification and relative quantification of library members.
