A nitrile butadiene elastomeric nanoparticle (NBENP) was used for modification of resol phenolic resin.The reaction between NBENP and resol was measured by FT-IR,and the curing behavior of resins was charactered by DS...A nitrile butadiene elastomeric nanoparticle (NBENP) was used for modification of resol phenolic resin.The reaction between NBENP and resol was measured by FT-IR,and the curing behavior of resins was charactered by DSC.The mecanical and thermal properties of modified resins were measured.Fra cture surface of modified phenolic resin was observed by SEM.The results showed that,the impact strength, flexural strength and heat resistance of NBENP modifie d phenolic resin were increased at the same time. A strong interface adhesion wa s formed because of the reaction between hydroxymethyl of resol and NBENP.This s pecial interface conduces to transmission of stress when materials were loaded,a nd inhibition of deformation and decomposition of phenolic matrix when heated.Th e microcrack,initiated with rubber particle,and cavitation of rubbers might be t he main reason for increase in toughness.The honeycomb structure in fracture sur face might be another possible reason for excellent mechanical properties.展开更多
Two carborane-containing resol phenolic resins（P1 and P2） with high boron content were synthesized via the reaction of carborane bisphenols（1 and 2） with formaldehyde in the presence of alkaline. HRMS results indi...Two carborane-containing resol phenolic resins（P1 and P2） with high boron content were synthesized via the reaction of carborane bisphenols（1 and 2） with formaldehyde in the presence of alkaline. HRMS results indicate that P1 is mainly composed of hydroxymethylated o-carborane bisphenols, the Mw of which was restrained around 500 due to the strong steric hindrance of o-carborane bisphenol. In contrast, the molecular weight of P2 was well regulated under various reaction conditions. The obtained resins were characterized with spectroscopic techniques including FTIR, 1H-NMR, ^13C-NMR, and 11B-NMR, which gave satisfactory results. TGA studies show that P2 shows char yield of 88.9% and 92.9% at 900 ℃ under nitrogen and air respectively. The imported carborane cage endows phenolic resin with ultrahigh char yield. Particularly, the char yield of the obtained carborane-containing phenolic resin under air is higher than that under nitrogen. FTIR and XRD confirm that the carborane cage could react with oxygen to form B2O3 at elevated temperatures, which postpones the thermal decomposition of phenolic resin and accounts for the high char yield.展开更多
The complexation reaction between borate ions and phenol-formaldehyde resol resin in aqueous solution was studied by pH measurement, small model molecules and infrared spectroscopy. The results show that the complexat...The complexation reaction between borate ions and phenol-formaldehyde resol resin in aqueous solution was studied by pH measurement, small model molecules and infrared spectroscopy. The results show that the complexation can proceed completely and rapidly at room temperature. Borate ion attacks phenol hydroxyl groups and adjacent position hydroxymethyl groups on the phenol ring of the resin, and forms the coordinate bond between boron atom in borate ion and oxygen atom in the hydroxyl groups. The complexation is a quantitative reaction. The complex is a six member ring containing two oxygens and one boron. The complexation can release hydrogen ions resulting in the decreasing pH in the resin solution.展开更多
The prepared methods and the gluability of resol resin adhesives containing cardboxymethlatedwood(CMW) as one of the main component were investigated. The carboxymethylated pine meal withweight increase(WI) 35～45% ca...The prepared methods and the gluability of resol resin adhesives containing cardboxymethlatedwood(CMW) as one of the main component were investigated. The carboxymethylated pine meal withweight increase(WI) 35～45% can easily dissolved in phenol by phenolysis. This CMW-phenol solu-tion can be resinificated by reaction with formaldehyde in presence of NaOH to obtain a clear watersoulble CMW-resol adhesive. It is found that the CMW-resol adhesives have good workable and ad-hesion properties and can achieve gluability which meets GB specification’s requirements for plywood.展开更多
[目的]研究家具用山杨改性的力学性能。[方法]使用甲阶酚醛树脂对山杨素材进行化学处理,通过比较试件抗弯弹性模量、抗弯强度和硬度,并结合实际情况,确定最佳工艺参数。[结果]最佳工艺参数:酚胶浓度为30%时,在绝对压力0.5 MPa的条件下...[目的]研究家具用山杨改性的力学性能。[方法]使用甲阶酚醛树脂对山杨素材进行化学处理,通过比较试件抗弯弹性模量、抗弯强度和硬度,并结合实际情况,确定最佳工艺参数。[结果]最佳工艺参数:酚胶浓度为30%时,在绝对压力0.5 MPa的条件下真空加压60 m in。[结论]在最佳工艺参数下山杨素材各方面性能得到最大提高。展开更多
Ⅰ. INTRODUCTION There exist many vibration-rotation transition lines between 5μm to 6.5μm in electric-discharge CO lasers with a low temperature or fast gas flow or chemical CO lasers. These lines will find wide ap...Ⅰ. INTRODUCTION There exist many vibration-rotation transition lines between 5μm to 6.5μm in electric-discharge CO lasers with a low temperature or fast gas flow or chemical CO lasers. These lines will find wide application in laser spectroscopy, laser chemistry, isotope separation, pollution monitoring, and optical pumping of other lasers. Since展开更多
Ⅰ.INTRODUCTION In modern physics (such as hypernuclei, baryonic structure and fractional parentage coefficient) symmetry group normal units are more and more useful. And it is thought that to deal with reduction of g...Ⅰ.INTRODUCTION In modern physics (such as hypernuclei, baryonic structure and fractional parentage coefficient) symmetry group normal units are more and more useful. And it is thought that to deal with reduction of groups product in terms of normal units is展开更多
This paper gives a characteristic property of the Euler characteristic for IBN rings. The following results: are proved. （1） If R is a commutative ring, M, N are two stable free R-modules, then χ（MN）=χ（M）χ（N...This paper gives a characteristic property of the Euler characteristic for IBN rings. The following results: are proved. （1） If R is a commutative ring, M, N are two stable free R-modules, then χ（MN）=χ（M）χ（N）, where χ denotes the Euler characteristic. （2） If f: K<sub>0</sub>（R）→Z is a ring isomorphism, where K<sub>0</sub>（R） denotes the Grothendieck group of R, K<sub>0</sub>（R） is a ring when R is commutative, then f（[M]）=χ（M） and χ（MN）=χ（M）χ（N） when M, N are finitely generated projective R-modules, where.the isomorphism class [M] is a generator of K<sub>0</sub>（R）. In addition, some applications of the results above are also obtained.展开更多
文摘A nitrile butadiene elastomeric nanoparticle (NBENP) was used for modification of resol phenolic resin.The reaction between NBENP and resol was measured by FT-IR,and the curing behavior of resins was charactered by DSC.The mecanical and thermal properties of modified resins were measured.Fra cture surface of modified phenolic resin was observed by SEM.The results showed that,the impact strength, flexural strength and heat resistance of NBENP modifie d phenolic resin were increased at the same time. A strong interface adhesion wa s formed because of the reaction between hydroxymethyl of resol and NBENP.This s pecial interface conduces to transmission of stress when materials were loaded,a nd inhibition of deformation and decomposition of phenolic matrix when heated.Th e microcrack,initiated with rubber particle,and cavitation of rubbers might be t he main reason for increase in toughness.The honeycomb structure in fracture sur face might be another possible reason for excellent mechanical properties.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.JD-1512)
文摘Two carborane-containing resol phenolic resins（P1 and P2） with high boron content were synthesized via the reaction of carborane bisphenols（1 and 2） with formaldehyde in the presence of alkaline. HRMS results indicate that P1 is mainly composed of hydroxymethylated o-carborane bisphenols, the Mw of which was restrained around 500 due to the strong steric hindrance of o-carborane bisphenol. In contrast, the molecular weight of P2 was well regulated under various reaction conditions. The obtained resins were characterized with spectroscopic techniques including FTIR, 1H-NMR, ^13C-NMR, and 11B-NMR, which gave satisfactory results. TGA studies show that P2 shows char yield of 88.9% and 92.9% at 900 ℃ under nitrogen and air respectively. The imported carborane cage endows phenolic resin with ultrahigh char yield. Particularly, the char yield of the obtained carborane-containing phenolic resin under air is higher than that under nitrogen. FTIR and XRD confirm that the carborane cage could react with oxygen to form B2O3 at elevated temperatures, which postpones the thermal decomposition of phenolic resin and accounts for the high char yield.
文摘The complexation reaction between borate ions and phenol-formaldehyde resol resin in aqueous solution was studied by pH measurement, small model molecules and infrared spectroscopy. The results show that the complexation can proceed completely and rapidly at room temperature. Borate ion attacks phenol hydroxyl groups and adjacent position hydroxymethyl groups on the phenol ring of the resin, and forms the coordinate bond between boron atom in borate ion and oxygen atom in the hydroxyl groups. The complexation is a quantitative reaction. The complex is a six member ring containing two oxygens and one boron. The complexation can release hydrogen ions resulting in the decreasing pH in the resin solution.
文摘The prepared methods and the gluability of resol resin adhesives containing cardboxymethlatedwood(CMW) as one of the main component were investigated. The carboxymethylated pine meal withweight increase(WI) 35～45% can easily dissolved in phenol by phenolysis. This CMW-phenol solu-tion can be resinificated by reaction with formaldehyde in presence of NaOH to obtain a clear watersoulble CMW-resol adhesive. It is found that the CMW-resol adhesives have good workable and ad-hesion properties and can achieve gluability which meets GB specification’s requirements for plywood.
文摘[目的]研究家具用山杨改性的力学性能。[方法]使用甲阶酚醛树脂对山杨素材进行化学处理,通过比较试件抗弯弹性模量、抗弯强度和硬度,并结合实际情况,确定最佳工艺参数。[结果]最佳工艺参数:酚胶浓度为30%时,在绝对压力0.5 MPa的条件下真空加压60 m in。[结论]在最佳工艺参数下山杨素材各方面性能得到最大提高。
文摘Ⅰ. INTRODUCTION There exist many vibration-rotation transition lines between 5μm to 6.5μm in electric-discharge CO lasers with a low temperature or fast gas flow or chemical CO lasers. These lines will find wide application in laser spectroscopy, laser chemistry, isotope separation, pollution monitoring, and optical pumping of other lasers. Since
文摘Ⅰ.INTRODUCTION In modern physics (such as hypernuclei, baryonic structure and fractional parentage coefficient) symmetry group normal units are more and more useful. And it is thought that to deal with reduction of groups product in terms of normal units is
基金The Project supported by National Natural Science Foundation of China.
文摘This paper gives a characteristic property of the Euler characteristic for IBN rings. The following results: are proved. （1） If R is a commutative ring, M, N are two stable free R-modules, then χ（MN）=χ（M）χ（N）, where χ denotes the Euler characteristic. （2） If f: K<sub>0</sub>（R）→Z is a ring isomorphism, where K<sub>0</sub>（R） denotes the Grothendieck group of R, K<sub>0</sub>（R） is a ring when R is commutative, then f（[M]）=χ（M） and χ（MN）=χ（M）χ（N） when M, N are finitely generated projective R-modules, where.the isomorphism class [M] is a generator of K<sub>0</sub>（R）. In addition, some applications of the results above are also obtained.
