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A novel benzoxazine monomer containing diacetylene linkage has been synthesized by applying an oxidative coupling approach. The structure is confirmed by 1 H and 13 C nuclear magnetic resonance (NMR) spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. Differential scanning calorimetry (DSC) is used to study crosslinking behavior of synthesized material. The benzoxazine...
Linear polymers with benzoxazine rings in the main chain have been synthesized applying click chemistry approach. These polymers possess molecular weights significantly higher than the benzoxazine polymers which have been chain extended via Mannich reaction. The number average molecular weight is estimated from size exclusion chromatography (SEC) to be between 20,000 and 40,000Da. The structure of...
Polybenzoxazine–polydimethylsiloxane (PBa–PDMS) hybrids were successfully prepared in situ by the ring-opening polymerization of benzoxazine (Ba) and the sol–gel process of diethoxydimethylsilane (DEDMS). The reaction conditions were optimized, and homogeneous opaque hybrid films were obtained up to 13wt% of PDMS content by using p-toluenesulfonic acid as the catalyst for sol–gel process. The domain...
Two series of high-performance polymer alloys were prepared by mixing typical benzoxine monomers, 3-phenyl-3,4-dihydro-2H-1,3-benzoxazine (P-a) or 6,6-(1-methylethyliden)-bis-(3,4-dihydro-3-phenyl-2H-1,3-benzoxazine) (B-a), with a typical bismaleimide, 4,4-bismaleimidodiphenyl methane by various ratios followed by thermal treatment up to 240°C. DSC and IR of the alloys were examined to follow the...
A series of organic–inorganic hybrid consisting of polyimide (PI) prepared from pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA), organically modified montmorillonite (OMMT) and polydimethylsiloxane (PDMS) were successfully prepared by in situ sol–gel process. OMMT was prepared by surface treatment of montmorillonite (MMT) with hexadecyltrimethylammonium bromide. X-ray diffraction (XRD)...
High molecular weight polybenzoxazine precursors have been synthesized from aromatic or aliphatic diamine and bisphenol-A with paraformaldehyde. The precursors were obtained as soluble white powder. Molecular weight was estimated from the size exclusion chromatography to be several thousands. The structure of the precursors was confirmed by IR, 1 H NMR and elemental analysis, indicating the...
Novel organic–inorganic hybrids were prepared from polybenzoxazine and titania using sol–gel process by blending titanium isopropoxide as a precursor for titania with a typical benzoxazine monomer, bis(3-phenyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane (Ba). Deep red brown and transparent hybrid materials were obtained after thermal cure at 200°C. DSC indicated that, in the presence of titania precursor,...
Several types of polybenzoxazine/clay hybrid nanocomposites have been prepared from organically modified montmorillonite (OMMT) and mono- or bifunctional benzoxazine, 3-phenyl-3,4-dihydro-2H-1,3-benzoxazine (Pa) or bis(3-phenyl-3,4-dihydro-2H-1,3-benzoxazinyl) isopropane (Ba), respectively. OMMT was prepared by a cation exchange of montmorillonite (MMT) with ammonium salts of amines such as tyramine,...
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