Synthesis and formulation of vinyl-containing polyacids for improved light-cured glass-ionomer cements

Vinyl-containing poly(acrylic acid-co-itaconic acid) copolymers were synthesized and used to formulate light-curable cements containing reactive glass fillers (Fuji II LC). The conditions for light curing were studied and optimized. Effects of molecular weight (MW), grafting ratio, comonomer, liquid composition, powder/liquid (P/L) ratio, glass powder and aging were evaluated. The results show that the vinyl-containing glass-ionomer cements (GICs) prepared in this study exhibit higher compressive strength (CS, 225.6 MPa), diametral tensile strength (DTS, 28.4 MPa) and much higher flexural strength (FS, 116.4 MPa), as compared to commercial Fuji II LC GIC (186.6 in CS, 19.1 in DTS and 57.1 in FS). The optimal light-exposure time was found to be around 10 min, and concentrations of CQ and DC were 0.5% (by weight) and 1.0%, respectively. Effects of MW, grafting ratio, P/L ratio and content of polymer in the liquid formulation were significant. The highest strengths were found for the optimal formulations where the MW was 15,000 (weight average), grafting ratio 25 mol%, P/L ratio 2.7 and liquid composition 50:20:30. During aging, the cement showed an increase of strength over the first week and then no change for a month. SEM analysis suggests that more integrated microstructures and smaller glass particles can lead to higher FS and higher polymer content in GICs leads to tough fracture surface and plastic deformation.     

共轭微孔聚合物及其复合材料的制备及应用

共轭微孔聚合物是一类具有扩展共轭体系的骨架材料,具有比表面积大、稳定性高、微孔大小和体积可精确调控等特点。由于其独特的结构特点,共轭微孔聚合物在各方面展现出巨大的应用潜力,本文综述了共轭微孔聚合物及复合材料的制备方法,以及共轭微孔聚合物在气体吸附和储存、污染物的富集、非均相催化、光发射、化学传感器、光捕集、电能存储等方面的应用。     

A phosphate-based epoxy resin for flame retardance: synthesis, characterization, and cure properties

A phosphorus-containing oligomer, bis(3-hydroxyphenyl) phenyl phosphate (BHPP), was synthesized through the reaction of phenyl dichlorophosphate and 1,3-dihydroxybenzene, and characterized by elemental analysis, Fourier transform IR spectroscopy, and ¹H NMR and ³¹P NMR spectroscopy. Consequently, the phosphate-based epoxy resins with a phosphorus content of 1 and 2 wt % were prepared via the reaction of diglycidyl ether of bisphenol-A with BHPP and bisphenol-A, and were confirmed with Fourier transform IR spectroscopy and gel permeation chromatography. Phenolic melamine, Novolak, and dicyanodiamide were used as curing agents to prepare the thermoset resins with the control and the phosphate-based epoxy resins. Thermal properties and thermal degradation behavior of these thermoset resins were investigated by using differential scanning calorimetry and thermogravimetric analysis. The thermoset resins cured with phenolic melamine exhibited higher glass-transition temperatures than the other cured resins owing to the high rigidity of their molecular chain. Thermogravimetric analysis studies demonstrated that the decomposition temperatures of the thermoset resins cured with Novolak were higher than those of the others. A synergistic effect from the combination of the phosphate-based epoxy resin and the nitrogen-containing curing agent can result in a great improvement of the flame retardance for their thermoset resins.     

Synthesis and characterization of novel multifunctional epoxy resin

A novel multifunctional epoxy resin was synthesized by polyphenol and epichlorohydrin.The structure and molecular weight ofthe multifunctional epoxy were characterized by FTIR and ESI-MS.DSC and DMTA were used to investigate the thermal propertyof multifunctional epoxy cured by DDS.The thermal resistance of the synthesized multifunctional epoxy was much better than astandard diglycidyl ether of bisphenol-A epoxy.     

Synthesis,characterization, thermal,and flame retardant properties of phosphate-based epoxy resins

A new phosphorus-containing oxirane bis-glycidyl phenylphosphate (BGPP), and a diamine, bis(4-aminophenyl)phenylphosphate (BAPP), were synthesized. Both of these two phosphorus-containing compounds lead to phosphate-containing epoxy resin via curing reaction. The kinetics of the curing reaction of BGPP with various curing agents, including BAPP, were studied. The introduction of electron-withdrawing group into the compounds increases the BGPP and decreases the BAPP reactivity in the curing reaction. The thermal and the weight loss behavior of the cured epoxy resins were studied by TGA. High char yields (32–52%) as well as high limiting oxygen index (LOI) values (34–49) of these phosphorylated resins were found, confirming the usefulness of these phosphorus-containing epoxy resins as flame retardants. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 565–574, 1997.     

Preparation of a novel composite particles and its application in the fluorescent detection of proteins

A new fluorescence method for the detection of proteins with novel composite nanoparticles (CdS/PPA) has been developed. The composite nanoparticles have been prepared through an in-situ polymerization method under ultrasonic irradiation. The surface of the composite nanoparticles was covered with functional groups (-COOH). These groups may play a major role in the improving the water solubility and biocompatibility of the nanoparticles. The composite particles is combined with proteins in NaAc-HCl buffer solution (pH=1.99), which can result in strong fluorescence, and the response is linearly proportional to the concentration of proteins. In λem/λex=650 nm/365 nm place (the stoke’ shift is 285 nm), its fluorescent strength reaches the maximum. Under the optimum conditions, the linear range is 0.10–20.0 μg·ml⁻¹ with the detection limit of 41 ng·ml⁻¹ for HSA, and 0.10–15.0 μg·ml⁻¹ with the detection limit of 35 ng·ml⁻¹ for Human γ-IgG . The method has been applied to the determination of the total protein in human serum samples collected from the hospital and the results are satisfactory.     

Synthesis, characterization, thermal properties and flame retardancy of a novel nonflammable phosphazene-based epoxy resin

Hexakis(4-hydroxyphenoxy)-cyclotriphosphazene (PN-OH) was synthesized through nucleophilic substitution of the chloride atoms of hexachlorocyclotriphosphazene and reduction of the aldehyde groups, and its chemical structure was characterized by elemental analysis, ¹H and ³¹P NMR, and Fourier transform infrared (FTIR) spectroscopy. A new phosphazene-based epoxy resin (PN-EP) was successfully synthesized through the reaction between diglycidyl ether of bisphenol-A (DGEBA) and PN-OH, and its chemical structure was confirmed by FTIR and gel permeation chromatography. Four PN-EP thermosets were obtained by curing with 4,4′-diaminodiphenylmethane (DDM), dicyandiamide (DICY), novolak and pyromellitic dianhydride (PMDA). The reactivity of PN-EP with the four curing agents presents an increase in the order of DDM, PMDA, novolak and DICY. An investigation on their thermal properties shows that the PN-EP thermosets achieve higher glass-transition and decomposition temperatures in comparison with the corresponding DGEBA ones while their char yields increase significantly. The PN-EP thermosets also exhibit excellent flame retardancy. The thermosets with novolak, DICY and PMDA achieve the LOI values above 30 and flammability rating of UL94 V-0, whereas the one with DDM reaches the V-1 rating. The nonflammable halogen-free epoxy resin synthesized in this study has potential applications in electric and electronic fields in consideration of the environment and human health.     

Aluminum phosphate-based solid acid catalysts: Facile synthesis,characterization and their application in the esterification of propanoic acid with n-butanol

Novel solid acid catalysts synthesized from aluminum phosphate were prepared via a precipitation method and a subsequent sulfating treatment. Their catalytic performances for the esterification of propanoic acid with n-butanol were investigated. The as-prepared catalysts were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption–desorption, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption of ammonia (NH₃-TPD), infrared spectroscopy of adsorbed pyridine, and other techniques. Experimental results of esterification reactions indicated that the calcination temperature can significantly affect the catalytic performances and the catalyst calcined at 500 °C (SO₄²⁻/AlPO₄-500) exhibited the highest activity. The effects of different reaction conditions including reaction time, reaction temperature, catalyst amount and alcohol/acid molar ratio were studied in detail. The maximum propanoic acid conversion of 91% was achieved under optimum reaction conditions. Furthermore, the as-prepared SO₄²⁻/AlPO₄-500 catalysts were tested for their reusability in repeated reaction cycles and could be effectively regenerated by a simple reactivation method.     

Synthesis and biological evaluation of novel steroid-linked nitrogen mustards

Two novel steroid-linked nitrogen mustard conjugates 1a and 1b were synthesized by using estrogenic acid 4 coupled with aniline mustard 8 and phenol mustard 13 in an esterification or amidation procedure. Preliminary cytotoxic screening on cancer cell lines in vitro showed that, the steroid-ester linked nitrogen mustard conjugate la exhibited obvious increasing of activities.     

Synthesis and properties of a copolymer of poly(l,4-phenylene sulfide)-poly(2,4-phenylene sulfide acid) and its nano-apatite reinforced composite

A new kind of copolymer of poly(1,4-phenylene sulfide)-poly(2,4-phenylene sulfide acid) (PPS-PPSA) and its nano-apatite (NA) composite have been obtained by polycondensation in l-methly-2-pyrrolidone (NMP). The NA content in the composite can reach 60 wt.%. The structures and properties of copolymer and its NA composite were studied though infrared spectroscopy. X-ray photoelectron spectroscopy, transmission electron microscopy, atomic force microscopy. The copolymer has high molecular weight and excellent thermal properties. There is a stable interface formed between NA and PPS-PPSA copolymer in the composite. NA keeps the original morphological structure and crystal behavior in the composite. The composites have good homogeneity and outstanding thermal stability. NA particles are uniformly distributed in the composite. The diameter of apatite in the composite is about 40-60 nm. The PPSA in the copolymer can increase the affinity to apatite and does not decrease the melting point and thermal stability of copolymer.     

Studies on synthesis,characterization and adhesive strength evaluation of KFA substituted resole adhesives

Preliminary investigations revealed the presence of appreciable amount of gum rich in lignin and tannin in kendu fruit (Diospyros Cordifolia Roxb). The kendu fruit adhesive (KFA) was used to substitute phenol in resole formulations to achieve cost effectiveness. Substituted resole formulations with 50 and 100% KFA were prepared in alkaline medium through stepwise addition process. Unsubstituted and KFA substituted resole adhesives were then characterized by FT‐IR, thermogravimetric analysis, differential scanning calorimetry and X‐ray diffraction analysis. The adhesive strength of the above mentioned formulations were evaluated by comparing the results of mechanical tests as per the ASTM specifications using UTM‐LR‐100K LLOYD Instruments, UK. Analytical characterizations revealed the substitutions of phenol by KFA in the substituted resole formulations. The results of adhesive strength test revealed that the 50% KFA substituted PF resin exhibits better adhesive strength than the virgin phenol‐formaldehyde and 100% KFA‐formaldehyde resole formulation. Copyright © 2001 John Wiley & Sons, Ltd.     

新型四氢苯并[4',5']噻吩并[3',2'∶5,6]吡啶并[4,3-d]嘧啶类化合物衍生物的合成及抗肿瘤活性

本文以环己酮为原料,通过氮杂Wittig反应合成了一系列结构新颖的取代四氢苯并噻吩并吡啶并嘧啶衍生物,并采用MTT法考察所合成目标化合物对CNE2、KB、MGC-803、MCF-7和PC3这5种肿瘤细胞的抑制活性。初步的生物活性结果表明,目标化合物对5种肿瘤细胞均有抑制活性,尤其是对胃癌MGC-803细胞展现出了更强的抑制活性。其中3-(4-氟苯基)-2-((4-氟苯基)氨基)-5-甲基-8,9,10,11-四氢苯并[4',5']噻吩并[3',2':5,6]吡啶并[4,3-d]嘧啶-4(3H)-酮[化合物8c,IC_(50)=(0. 9±0. 25)μmol·L~(-1)]对MGC-803的活性最强,是5-氟尿嘧啶[IC_(50)=(18. 4±1. 43)μmol·L~(-1)]的20倍;同时,目标化合物对正常的胃黏膜上皮细胞GES-1没有毒性。四氢苯并[4',5']噻吩并[3',2':5,6]吡啶并[4,3-d]嘧啶类化合物具有良好的抗肿瘤活性,值得进一步深入研究。     

Facile synthesis and characterization of novel pseudo-hypercrosslinked resin

A kind of pseudo-hypercrosslinked polymer resin was firstly synthesized via a continuous Friedel-Crafts alkylation poly- merization of benzene, diphenyl and their dichloromethyl derivatives. And the micromorphology and adsorption properties of these resins were investigated. The results demonstrated that the novel resins have high-specific surface area （581.26-974.88 m^2/g）, high- pore volume （0.56-1.65 mL/g）, small average porous radius （1.93-3.67 nm） and excellent adsorption properties for small non-polar organic molecules.     

Synthesis and characterisation of a novel Y-shaped liquid crystalline epoxy and its effect on isotropic epoxy resin

ABSTRACT

A novel Y-shaped liquid crystalline epoxy with a rigid core with three flexible liquid crystalline arms (ETTPM) was synthesised and its structure was characterised by Fourier transform infrared spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. It was analysed and observed by differential scanning calorimetry, X-ray diffraction and polarised optical microscopy (POM) that the liquid crystal phase was stable on the temperature range of 107.8°C. In particular, an unusual transition phenomenon of liquid crystal phases was observed. Modified epoxy-resin-cured products were prepared using ETTPM, epoxy resin E51 and 4,4-diaminodiphenyl methane. The liquid crystalline domains in cured products were observed by researching their scattering effect on laser. Mechanical tests showed that ETTPM was effective for the mechanical properties improvement of epoxy-resin-cured products, as demonstrated in the improvement of impact strength, tensile strength and tensile elasticity modulus. The impact fracture cross-sections and surface morphologies were studied further by POM and scanning electron microscopy (SEM). Crack deformation, crack split and notable plastic deformations were found in modified epoxy-resin-cured products, and these factors played important roles in improving the impact strength.     

Synthesis and cytotoxicity evaluation of a novel justicidin G analogue and its phosphate ester

The novel justicidin G analogue 13 and its phosphate ester 15 were synthesized as potential anticancer agents in several steps starting from commercially available methyl gallate and veratraldehyde. The cytotoxicity of the intermediates was tested against HCT-8, BEL-7402, KETR3, HELA, BGC-823, KB and MCF-7 cell lines by the MTT test, and compound 15 exhibited significant cytotoxicity in HELA and KB cell lines.     

Synthesis and characterisation of a novel surfactant, sodium geranyl sulphate

An anionic surfactant, sodium geranyl sulphate (sodium 3,7-dimethyl-2,6-octadienyl sulphate), was synthesised from the natural extracted monoterpenol, geraniol. The final product yield is 51.5% after recrystallisation. The cis/trans isomer reduced the surface tension of water to 33 ± 0 mN m⁻¹ and yielded a critical micelle concentration of 89 ± 7 mM.     

Synthesis and properties of 3-acyl-γ-pyrones, a novel class of flavones and chromones

Using modified Baker-Venkataraman reaction a novel class of 3-acyl flavones and chromones have been synthesised. Reaction mechanism for their formation have been elucidated. The properties of 3-acyl flavonoids indicate them to be precursors for the synthesis of flavones.     

An experimental investigation of wear of glass fibre-epoxy resin and glass fibre-polyester resin composite materials

In this paper, the effects of resin content on the wear of woven roving glass fibre-epoxy resin and glass fibre-polyester resin composite materials have been examined. Furthermore, composite materials are experimentally investigated under different loads and speeds by using a block-on-shaft wear tester. The influences of two thermosetting resins epoxy and polyester on the wear of glass-woven roving reinforced composites under has been investigated dry conditions. The glass fibre-epoxy resin and the glass fibre-polyester resin composite materials specimens have been tested under different experiment conditions. Tests were conducted for 0.39 and 0.557 m/s speeds, at two different loads of 5 and 10 N. The weight losses were measured after measuring different sliding distances. Wear in the experiments was determined as weight loss. For each experiment, one specimen was used. The amount of wear was measured before the experiment and after the experiment with the apparatus of balance scales with the accuracy of 10⁻³ g. Glass fibre-epoxy resin composites generally showed higher strength and minimum wear when compared with glass fibre-polyester resin composites materials. In addition, Scanning electron microscopy (SEM) is used to study the worn surface to verify the results.     

Synthesis and biological evaluation of novel pyrazole carboxamide with diarylamine-modified scaffold as potent antifungal agents

Twenty-seven novel pyrazole carboxamides with diarylamine-modified scaffold were designed, synthesized and characterized in detail via ¹H NMR, ¹³C NMR, IR and ESI-HRMS. Preliminary bioassays showed that some of the target compounds exhibited good antifungal activity against Rhizoctonia solani, Rhizoctonia cerealis and Sclerotinia sclerotiorum. Among them, compound 9c-7 exhibited the highest antifungal activities against R. solani, R. cerealis and S. sclerotiorum in vitro with IC₅₀ values of 0.013, 1.608 and 1.874 μg/mL, respectively. Notably, compound 9c-7 still presented the highest fungicidal activities against R. solani in vivo with an IC₅₀ value of 22.21 μg/mL. Molecular docking simulation results reveal that compound 9c-7 binds well to the hydrophobic pockets of the receptor protein succinate dehydrogenase. This study suggests that compound 9c-7 could act as a potential fungicide to be used for further optimization.     

醇体系中新型晶体磷酸锆的合成和表征

醇体系中新型晶体磷酸锆的合成和表征赵玉娥，宋天佑，徐家宁，徐如人（吉林大学化学系，长春，１３００２３）关键词磷酸锆，合成，表征自１９６４年首次合成磷酸锆晶体［１］以来，人们又合成出多种磷酸锆晶体［２～４］。但在非水体系中合成磷酸锆的工作尚未见报道。本...