Using brighten white and modified PET chips, fine denier hollow fibres (dpf=0.5～1.5) were prepared on a Fuji Filter MSTC-400 and VC-443A drawn machine, whose structure and properties were tested by X-ray diffraction ...Using brighten white and modified PET chips, fine denier hollow fibres (dpf=0.5～1.5) were prepared on a Fuji Filter MSTC-400 and VC-443A drawn machine, whose structure and properties were tested by X-ray diffraction mater, SOM-II sonic velocity meter and Instron-1122 Tensile tester, electron and light microscopy etc,. The results show: fine denier hollow taken-up yarns prepared at low spinning velocity have radial orientation, higher strength and elongation at rupture because radial stress is higher than normal stress. Fine denier hollow drawn yarns with hollow degree up to 18～35％ and high tenacity, together with high crystalline degree and small crystal and amorphous domains, can be empolyed as products.展开更多
The PET fibrc was grafted with acrylonitrile (AN) initiated by benzoyl peroxide(BPO). Then the AN-grafted fibre was treated in a solution containing copper-compound and sulfur reducing agent to obtain the electrically...The PET fibrc was grafted with acrylonitrile (AN) initiated by benzoyl peroxide(BPO). Then the AN-grafted fibre was treated in a solution containing copper-compound and sulfur reducing agent to obtain the electrically conductive PET fibre. In this paper the factors affecting the graft copolymerization were discussed and the optimum conditions of graft were then chosen. The conductive components of the electrically conductive PET fibre and their structures were also studied with the aid of X-ray diffractometry and X-ray photoelectron spectrometry. The properties of the conductive fibre, such as electric resistivity. Tm and tensile strength, were展开更多
This paper presents a composite model of the natural keratin fibres (wool and hair) whichconsists essentially of isotropic viscoelastic filaments, oriented parallel to each other in the fibreaxial direction, embedded ...This paper presents a composite model of the natural keratin fibres (wool and hair) whichconsists essentially of isotropic viscoelastic filaments, oriented parallel to each other in the fibreaxial direction, embedded in an isotropic viscoelastic matrix. The model accurately fits the exper-imental data on the fibre axial stress relaxation moduli and provides upper and lower bounds forthe initial/final values for the fibre transverse tensile and shear stress relaxation moduli andtransverse Poisson’s ratio. The partially water penertrable filament phase of the composite modelis identified as the microfibrils in the fine structure of keratin. The strong anisotropy of keratinsin mechanical properties and hygral/thermal expansion is analyzed in terms of composite struc-ture and mechanical as well as the thermal/hygral properties of the two constituent phases.展开更多
A series of glass fibre reinforced composites based on novel blend matrices were fabricated us-ing reaction injection moulding （RIM） processing.The blends were made of sub-sequentialinterpenetrating polymer networks...A series of glass fibre reinforced composites based on novel blend matrices were fabricated us-ing reaction injection moulding （RIM） processing.The blends were made of sub-sequentialinterpenetrating polymer networks of acrylic-polyurea or acrylic-copoly（urea-isocyanurate）.Themechanical and thermal properties were characterized by tensile test and dynamic mechanical ana-lysis.The fracture data from single edge notch bend tests were analysed using fracture mechanicsfor the composites to give K<sub>IC</sub> and G<sub>IC</sub>.The correlation between reaction kinetics and morphologyof the blend and the composite properties were discussed.The investigations showed that the novelblends have good bonding property on glass fibre,thus good processability in RIM,and the re-suited composites have good mechanical and thermal properties.展开更多
The impregnation of a special grade polyacrylonitrile （PAN） precursor fibres was carried out in a 8 wt. % KMnO4 aqueous solution to obtain modified PAN precursor fibres. The foctts is primarily on the effects of mod...The impregnation of a special grade polyacrylonitrile （PAN） precursor fibres was carried out in a 8 wt. % KMnO4 aqueous solution to obtain modified PAN precursor fibres. The foctts is primarily on the effects of modification on the chemical structure and the physical mechanical properties of precursor ribres, them-aft stabilised and their resulting carbon fibres, which were characterized by the con-bination use of densities, wide-angle X-my diffraction （WAXD）, X-my photoelectron spectrosopy （XPS）, Elemental analysis （EA）, Fourier transform infrared （FT-IR） and scanning clectronmicroscope （SEM）, etc. KMnO4 as a strong oxidizer can swell, oxidize and corrode the skin of a precursor fibre, tin, form partly C≡N groups to C=N ones, decrcase the crystal size, increase the orientation index, increase the crystallinity index, furthermore increase the densities of modified PAN precursors and resulting thermal stabiliscd fibres. As a result, the carbonfibres developed from modified PAN fibres show an improvement in tensile strength of 31.25% and an improvement in elongation of 77.78%, but a decrease of 16.52% in Young＇s modulus.展开更多
Free\|radical solution copolymerization of itaconic acid and acrylonitrile was carried out in DMSO at 58～60℃ using azodiisobutyronitrile as initiator.The resulting polymerization solution was spun to form PAN precur...Free\|radical solution copolymerization of itaconic acid and acrylonitrile was carried out in DMSO at 58～60℃ using azodiisobutyronitrile as initiator.The resulting polymerization solution was spun to form PAN precursors of carbon fibres.The precursors were treated with NiSO 4 aqueous solution at 95℃ on line.The structure and properties of untreated and treated PAN precursors and resultant carbon fibres were characterized by IR,SEM,dynamic viscoelasticity study,stabilization process and so on.It was suggested that carbon fibres developed from modified PAN fibres showed an improvement in tensile strength by about 20%～30% and Young’s modulus by about 5%～10%.展开更多
采用光学显微镜(LM)和扫描电子显微镜(SEM)并结合Kajaan i FS200分析仪研究了沙柳(Salix psamm ophilaC.W ang et Ch.Y.Yang)的纤维形态和解剖结构。结果表明:沙柳主要由导管、木纤维、木射线薄壁细胞及少量轴向薄壁细胞组成。沙柳属于...采用光学显微镜(LM)和扫描电子显微镜(SEM)并结合Kajaan i FS200分析仪研究了沙柳(Salix psamm ophilaC.W ang et Ch.Y.Yang)的纤维形态和解剖结构。结果表明:沙柳主要由导管、木纤维、木射线薄壁细胞及少量轴向薄壁细胞组成。沙柳属于阔叶木散孔材,年轮界限明显,木射线单列同型、导管上的纹孔排列方式较复杂。通过与毛白杨、麦草和红松的形态学参数比较研究发现,沙柳虽然属于短纤维,纤维平均长度为0.52 mm,但是其纤维含量较高,纤维形态良好,长宽比值较大,壁腔比值较小,有助于在打浆抄纸过程中形成纤维间良好的结合,提高纸张的物理强度,是良好的造纸原料。展开更多
文摘Using brighten white and modified PET chips, fine denier hollow fibres (dpf=0.5～1.5) were prepared on a Fuji Filter MSTC-400 and VC-443A drawn machine, whose structure and properties were tested by X-ray diffraction mater, SOM-II sonic velocity meter and Instron-1122 Tensile tester, electron and light microscopy etc,. The results show: fine denier hollow taken-up yarns prepared at low spinning velocity have radial orientation, higher strength and elongation at rupture because radial stress is higher than normal stress. Fine denier hollow drawn yarns with hollow degree up to 18～35％ and high tenacity, together with high crystalline degree and small crystal and amorphous domains, can be empolyed as products.
文摘The PET fibrc was grafted with acrylonitrile (AN) initiated by benzoyl peroxide(BPO). Then the AN-grafted fibre was treated in a solution containing copper-compound and sulfur reducing agent to obtain the electrically conductive PET fibre. In this paper the factors affecting the graft copolymerization were discussed and the optimum conditions of graft were then chosen. The conductive components of the electrically conductive PET fibre and their structures were also studied with the aid of X-ray diffractometry and X-ray photoelectron spectrometry. The properties of the conductive fibre, such as electric resistivity. Tm and tensile strength, were
文摘This paper presents a composite model of the natural keratin fibres (wool and hair) whichconsists essentially of isotropic viscoelastic filaments, oriented parallel to each other in the fibreaxial direction, embedded in an isotropic viscoelastic matrix. The model accurately fits the exper-imental data on the fibre axial stress relaxation moduli and provides upper and lower bounds forthe initial/final values for the fibre transverse tensile and shear stress relaxation moduli andtransverse Poisson’s ratio. The partially water penertrable filament phase of the composite modelis identified as the microfibrils in the fine structure of keratin. The strong anisotropy of keratinsin mechanical properties and hygral/thermal expansion is analyzed in terms of composite struc-ture and mechanical as well as the thermal/hygral properties of the two constituent phases.
文摘A series of glass fibre reinforced composites based on novel blend matrices were fabricated us-ing reaction injection moulding （RIM） processing.The blends were made of sub-sequentialinterpenetrating polymer networks of acrylic-polyurea or acrylic-copoly（urea-isocyanurate）.Themechanical and thermal properties were characterized by tensile test and dynamic mechanical ana-lysis.The fracture data from single edge notch bend tests were analysed using fracture mechanicsfor the composites to give K<sub>IC</sub> and G<sub>IC</sub>.The correlation between reaction kinetics and morphologyof the blend and the composite properties were discussed.The investigations showed that the novelblends have good bonding property on glass fibre,thus good processability in RIM,and the re-suited composites have good mechanical and thermal properties.
基金HAIPURT(No.2006KYCX009)National Natural Science Foundation of Henan(No.2006430019)Hanan Innvation Project(No.0523021300)
文摘The impregnation of a special grade polyacrylonitrile （PAN） precursor fibres was carried out in a 8 wt. % KMnO4 aqueous solution to obtain modified PAN precursor fibres. The foctts is primarily on the effects of modification on the chemical structure and the physical mechanical properties of precursor ribres, them-aft stabilised and their resulting carbon fibres, which were characterized by the con-bination use of densities, wide-angle X-my diffraction （WAXD）, X-my photoelectron spectrosopy （XPS）, Elemental analysis （EA）, Fourier transform infrared （FT-IR） and scanning clectronmicroscope （SEM）, etc. KMnO4 as a strong oxidizer can swell, oxidize and corrode the skin of a precursor fibre, tin, form partly C≡N groups to C=N ones, decrcase the crystal size, increase the orientation index, increase the crystallinity index, furthermore increase the densities of modified PAN precursors and resulting thermal stabiliscd fibres. As a result, the carbonfibres developed from modified PAN fibres show an improvement in tensile strength of 31.25% and an improvement in elongation of 77.78%, but a decrease of 16.52% in Young＇s modulus.
文摘Free\|radical solution copolymerization of itaconic acid and acrylonitrile was carried out in DMSO at 58～60℃ using azodiisobutyronitrile as initiator.The resulting polymerization solution was spun to form PAN precursors of carbon fibres.The precursors were treated with NiSO 4 aqueous solution at 95℃ on line.The structure and properties of untreated and treated PAN precursors and resultant carbon fibres were characterized by IR,SEM,dynamic viscoelasticity study,stabilization process and so on.It was suggested that carbon fibres developed from modified PAN fibres showed an improvement in tensile strength by about 20%～30% and Young’s modulus by about 5%～10%.
文摘采用光学显微镜(LM)和扫描电子显微镜(SEM)并结合Kajaan i FS200分析仪研究了沙柳(Salix psamm ophilaC.W ang et Ch.Y.Yang)的纤维形态和解剖结构。结果表明:沙柳主要由导管、木纤维、木射线薄壁细胞及少量轴向薄壁细胞组成。沙柳属于阔叶木散孔材,年轮界限明显,木射线单列同型、导管上的纹孔排列方式较复杂。通过与毛白杨、麦草和红松的形态学参数比较研究发现,沙柳虽然属于短纤维,纤维平均长度为0.52 mm,但是其纤维含量较高,纤维形态良好,长宽比值较大,壁腔比值较小,有助于在打浆抄纸过程中形成纤维间良好的结合,提高纸张的物理强度,是良好的造纸原料。
