The aim of this study is to investigate the effect of chemical extraction method on the properties of doum palm fibres. The method of extraction which is carried out is a soda treatment. First, an investigation of the...The aim of this study is to investigate the effect of chemical extraction method on the properties of doum palm fibres. The method of extraction which is carried out is a soda treatment. First, an investigation of the extraction processes was undertaken. Secondly, the physical properties (surface morphology, density, linear density and diameter), the mechanical properties (tenacity, strain) and chemical properties (FT-IR spectra) of doum palm fibres were inspected. Finally, a comparison between properties of doum palm fibres and other vegetal ones has been included. Results indicates an influence of soda treatment on properties of Doum palm fibers. In fact, there is an improvement on fibers diameter and linear density while increasing soda concentration, temperature and treatment duration. Moreover, the studied fibers have a low density which does not exceed 1. The fibers tenacity achieved the maximum value of 20.86 cN/Tex when precessing in the following combination (0.75 N, 100°C and 180 mn). In the end, the FTIR spectra reveals a change in structure after this alkali treatment while increasing the cellulose amount exposed on the fiber surface and consequently the number of possible reaction sites (OH groups).展开更多
Plasma treatment can be used to modify the structure of natural fibre like jute for a variety of applications. Environmentally friendly jute fibre was treated with argon and oxygen plasma. The treated samples were cha...Plasma treatment can be used to modify the structure of natural fibre like jute for a variety of applications. Environmentally friendly jute fibre was treated with argon and oxygen plasma. The treated samples were characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR） and optical microscope. The macromolecular and microstructural changes in cellulose confirmed the change by plasma treatment. The XRD results confirmed that the crystal size and the crystallinity of the plasma treated fibre increased. Argon plasma treated fibre had a smooth and compact surface, compared to oxygen plasma treated fibre. The maximum stain （i.e. stress） concentrated in the oxygen plasma treated fibre. Optical micrographs showed the oxygen plasma treated fibre tended to rupture due to higher strain （i.e., stress） compared to fibre with argon plasma treatment. FTIR results also provided the evidence of change in the chemical constituents with plasma treatment.展开更多
This review is based on the surface treatment of natural fibres which can be used in technical applications. Natural fibres on their own have some draw backs regarding moisture uptake, quality variations, low thermal ...This review is based on the surface treatment of natural fibres which can be used in technical applications. Natural fibres on their own have some draw backs regarding moisture uptake, quality variations, low thermal stability, and poor wettability. Insufficient adhesion between polymer matrix and fibre leads in time to debonding. Overcoming the weaknesses of these natural fibres gave the motivation for this study where physical and chemical methods of modification were considered. Physical methods such as electric discharge and mercerization were reported as well as the chemical methods such as graft copolymerization and treatment with isocyanates, and the results due to these modifications were discussed. This study reveals that natural fibres are good candidates for reinforcement but they have to be suitably treated to improve their properties if they are to be used in technical applications. The various fibre surface treatments actually improve the interfacial adhesion between the fibre surface and the matrix, thereby giving good mechanical properties to the resulted polymer composites.展开更多
The G3 and CBS-QB3 theoretical methods are employed to study the decomposition of CF3OH into FCFO and HF by water, water dimmer, and ammonia. The decomposition of CF3OH into FCFO and HF is unlikely to occur in the atm...The G3 and CBS-QB3 theoretical methods are employed to study the decomposition of CF3OH into FCFO and HF by water, water dimmer, and ammonia. The decomposition of CF3OH into FCFO and HF is unlikely to occur in the atmosphere due to the high activated energy of 88.7 k J/mol at the G3 level of theory. However, the computed results predict that the barrier for unimolecular decomposition of CF3OH is decreased to 25.1 kJ/mol from 188.7 k J/mol with the aid of NH3 at the G3 level of theory, which shows that the ammonia play a strong catalytic effect on the split of CF3OH. In addition, the calculated rate constants show that the decomposition of CF3OH by NH3 is faster than those of H2O and the water dimmer by 10^9 and 10^5 times respectively. The rate constants combined with the corresponding concentrations of these species demonstrate that the reaction CF3OH with NH3 via TS4 is of great importance for the decomposition of CF3OH in the atmosphere.展开更多
According to data collected from 1935 statistics-worthy Chinese chemical fibre enterprises surveyed by National Bureau of Statistics of China, the total profits reached CNY8.066 billion in Jan. -May, 2010, up 200.08 p...According to data collected from 1935 statistics-worthy Chinese chemical fibre enterprises surveyed by National Bureau of Statistics of China, the total profits reached CNY8.066 billion in Jan. -May, 2010, up 200.08 per cent y/y, 234.78 percentage points higher than the Jan.-May 2009 period. Technology improvement and industrial structural adjustment played a very major role on profi t growth.展开更多
Recently recommended by China Chemical Fibre Industry Association(CCFA),four companies of Jiangsu Shenghong Chemical Fibre Co.,Ltd.,Jiangsu Hengli Chemical Fibre Co.,Ltd.,Jiangsu Yingxiang Chemical Fibre Company Limit...Recently recommended by China Chemical Fibre Industry Association(CCFA),four companies of Jiangsu Shenghong Chemical Fibre Co.,Ltd.,Jiangsu Hengli Chemical Fibre Co.,Ltd.,Jiangsu Yingxiang Chemical Fibre Company Limited,Jiangsu Xinmin Technology Co.,Ltd.展开更多
According to National Bureau of Statistics of China,from January to May 2010,total profits of China’s Chemical Fibre Industry jumped 200 per cent to 8.066 billion yuan.The production rose 13.43 percent y/y to 14.4739...According to National Bureau of Statistics of China,from January to May 2010,total profits of China’s Chemical Fibre Industry jumped 200 per cent to 8.066 billion yuan.The production rose 13.43 percent y/y to 14.4739 million tons in the f irst half of 2010.Goods delivered for chemical fiber exports increased by 50.21 per cent to 792,000 from January to May from the year-earlier period.展开更多
文摘The aim of this study is to investigate the effect of chemical extraction method on the properties of doum palm fibres. The method of extraction which is carried out is a soda treatment. First, an investigation of the extraction processes was undertaken. Secondly, the physical properties (surface morphology, density, linear density and diameter), the mechanical properties (tenacity, strain) and chemical properties (FT-IR spectra) of doum palm fibres were inspected. Finally, a comparison between properties of doum palm fibres and other vegetal ones has been included. Results indicates an influence of soda treatment on properties of Doum palm fibers. In fact, there is an improvement on fibers diameter and linear density while increasing soda concentration, temperature and treatment duration. Moreover, the studied fibers have a low density which does not exceed 1. The fibers tenacity achieved the maximum value of 20.86 cN/Tex when precessing in the following combination (0.75 N, 100°C and 180 mn). In the end, the FTIR spectra reveals a change in structure after this alkali treatment while increasing the cellulose amount exposed on the fiber surface and consequently the number of possible reaction sites (OH groups).
文摘Plasma treatment can be used to modify the structure of natural fibre like jute for a variety of applications. Environmentally friendly jute fibre was treated with argon and oxygen plasma. The treated samples were characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR） and optical microscope. The macromolecular and microstructural changes in cellulose confirmed the change by plasma treatment. The XRD results confirmed that the crystal size and the crystallinity of the plasma treated fibre increased. Argon plasma treated fibre had a smooth and compact surface, compared to oxygen plasma treated fibre. The maximum stain （i.e. stress） concentrated in the oxygen plasma treated fibre. Optical micrographs showed the oxygen plasma treated fibre tended to rupture due to higher strain （i.e., stress） compared to fibre with argon plasma treatment. FTIR results also provided the evidence of change in the chemical constituents with plasma treatment.
文摘This review is based on the surface treatment of natural fibres which can be used in technical applications. Natural fibres on their own have some draw backs regarding moisture uptake, quality variations, low thermal stability, and poor wettability. Insufficient adhesion between polymer matrix and fibre leads in time to debonding. Overcoming the weaknesses of these natural fibres gave the motivation for this study where physical and chemical methods of modification were considered. Physical methods such as electric discharge and mercerization were reported as well as the chemical methods such as graft copolymerization and treatment with isocyanates, and the results due to these modifications were discussed. This study reveals that natural fibres are good candidates for reinforcement but they have to be suitably treated to improve their properties if they are to be used in technical applications. The various fibre surface treatments actually improve the interfacial adhesion between the fibre surface and the matrix, thereby giving good mechanical properties to the resulted polymer composites.
基金This work was supported by the National Natural Science Foundation of China （No.10865003） and the Guizhou University for Nationalities （2010）. The authors thank professors W. T. Duncan, R. L. Bell, and T. N. Truong or providing the rate program through the internet.
文摘The G3 and CBS-QB3 theoretical methods are employed to study the decomposition of CF3OH into FCFO and HF by water, water dimmer, and ammonia. The decomposition of CF3OH into FCFO and HF is unlikely to occur in the atmosphere due to the high activated energy of 88.7 k J/mol at the G3 level of theory. However, the computed results predict that the barrier for unimolecular decomposition of CF3OH is decreased to 25.1 kJ/mol from 188.7 k J/mol with the aid of NH3 at the G3 level of theory, which shows that the ammonia play a strong catalytic effect on the split of CF3OH. In addition, the calculated rate constants show that the decomposition of CF3OH by NH3 is faster than those of H2O and the water dimmer by 10^9 and 10^5 times respectively. The rate constants combined with the corresponding concentrations of these species demonstrate that the reaction CF3OH with NH3 via TS4 is of great importance for the decomposition of CF3OH in the atmosphere.
文摘According to data collected from 1935 statistics-worthy Chinese chemical fibre enterprises surveyed by National Bureau of Statistics of China, the total profits reached CNY8.066 billion in Jan. -May, 2010, up 200.08 per cent y/y, 234.78 percentage points higher than the Jan.-May 2009 period. Technology improvement and industrial structural adjustment played a very major role on profi t growth.
文摘Recently recommended by China Chemical Fibre Industry Association(CCFA),four companies of Jiangsu Shenghong Chemical Fibre Co.,Ltd.,Jiangsu Hengli Chemical Fibre Co.,Ltd.,Jiangsu Yingxiang Chemical Fibre Company Limited,Jiangsu Xinmin Technology Co.,Ltd.
文摘According to National Bureau of Statistics of China,from January to May 2010,total profits of China’s Chemical Fibre Industry jumped 200 per cent to 8.066 billion yuan.The production rose 13.43 percent y/y to 14.4739 million tons in the f irst half of 2010.Goods delivered for chemical fiber exports increased by 50.21 per cent to 792,000 from January to May from the year-earlier period.
