Flax fiber(FF) was used to reinforce wood flour/high density polyethylene composites(WF/PE).WF/PE particles were uniformly mixed with FF via high-speed mixing and then extruded with a single screw extruder to prepare ...Flax fiber(FF) was used to reinforce wood flour/high density polyethylene composites(WF/PE).WF/PE particles were uniformly mixed with FF via high-speed mixing and then extruded with a single screw extruder to prepare FF reinforced WF/PE composites(FF/WF/PE).Mechanical testing,dynamic mechanical analysis,scanning electron microscopy(SEM),creep measurement and Torque rheology were used to characterize the resulting composites.The results indicate that the mechanical performance of the composites could be remarkably improved by adding a limited amount of FF.The flexural strength and modulus increased by 14.6 and 51.4%,respectively(FF content of 9 wt%),while the unnotched impact strength could be increased by 26.5%(FF content of12 wt%).The creep resistance and toughness of thecomposite was markedly improved without changing the plastic content of the composite material.展开更多
The large number of oily wastewater discharges and oil spills are bringing about severe threats to environment and human health.Corresponding to this challenge,a functional PAA-ZnO-HDTMS flax fiber with UV-induced swi...The large number of oily wastewater discharges and oil spills are bringing about severe threats to environment and human health.Corresponding to this challenge,a functional PAA-ZnO-HDTMS flax fiber with UV-induced switchable wettability was developed for efficient oil-water separation in this study.The developed flax fiber was obtained through PAA grafted polymerization and then ZnO-HDTMS nanocomposite immobilization.The as-prepared PAA-ZnO-HDTMS flax fiber was hydrophobic initially and could be switched to hydrophilic through UV irradiation.Its hydrophobicity could be easily recovered through being stored in dark environment for several days.To optimize the performance of the PAA-ZnO-HDTMS flax fiber,the effects of ZnO and HDTMS concentrations on its switchable wettability were investigated.The optimized PAA-ZnO-HDTMS flax fiber had a large water contact angle(∼130°)in air and an extremely small oil contact angle(∼0°)underwater initially.After UV treatment,the water contact angle was decreased to 30°,while the underwater oil contact angle was increased to more than 150°.Based on this UV-induced switchable wettability,the developed PAA-ZnO-HDTMS flax fiber was applied to remove oil from immiscible oil-water mixtures and oil-in-water emulsion with great reusability for multiple cycles.Thus,the developed flax fiber could be further fabricated into oil barrier or oil sorbent for oil-water separation,which could be an environmentally-friendly alternative in oil spill response and oily wastewater treatment.展开更多
The aim of this study is to show the interest of the mechanical and dynamical properties of glass-flax hybrid composites.Therefore,various staking sequences of glass-flax hybrid composites were manufactured and tested...The aim of this study is to show the interest of the mechanical and dynamical properties of glass-flax hybrid composites.Therefore,various staking sequences of glass-flax hybrid composites were manufactured and tested in free vibrations.The damping coefficients were identified by fitting the experimental responses of free-free bending vibrations.The obtained results show that the staking sequences and the position of flax fiber layers in the hybrid composites changed the properties,so a classification of different stacking sequences was established.In fact,the hybrid laminate made of two glass external layers placed on both sides of four flax layers is very interesting in term of its mechanical and damping properties.Indeed,it showed better specific bending modulus and loss factor than glass composites with proportions of 31 and 39%,respectively.A study of a structure of this composite has been made to validate the obtained results.展开更多
Flax and hemp fibers were used as reinforcing materials to commingle with polypropylene(PP)fiber to realize the mixture of two materials at the stage of yarn.Meanwhile,PP filaments were introduced to produce a core-sp...Flax and hemp fibers were used as reinforcing materials to commingle with polypropylene(PP)fiber to realize the mixture of two materials at the stage of yarn.Meanwhile,PP filaments were introduced to produce a core-spun yarn with flax/PP as core and PP filament as outer sheath.The commingled yarns were woven into 2D fabric which was used as the prefabricated material.The composite laminates were prepared by hot press technology.The effects of manufacture technology,yarn structure,and fiber weight fraction on flexural properties of composites were investigated.展开更多
The effecf of potassium fertilizer on Nitrate Reductase Activity (NRA), Hydrogen Peroxide Activity (HPA),Peroxidase Activity (PODA) in the fiber flax was studied on campus of NEAU in 1995 and 1996. The result showed t...The effecf of potassium fertilizer on Nitrate Reductase Activity (NRA), Hydrogen Peroxide Activity (HPA),Peroxidase Activity (PODA) in the fiber flax was studied on campus of NEAU in 1995 and 1996. The result showed that the changing of NRA,HPA and PODA was same in the period from the quick growth to blossom period in the different treamets. NAR and HPA was the highest in the quick growth period then cut down gradually,and PODA was just right contrary. The other side,it was obviously different to NRA, HPA and PODA in the different Potassium levels. NRA and HPA presented the highest enzyme activity in the trea- ment of K2O 22.5kg·ha-1 PODA in creased gradually with the increase of Potassium. PODA was the high- est in the treament of K2O 67.5kg·ha-1. But all of the Potassium treatments was higher than CK whatever NRA,HPA and PODA. Potassium may enhanced the primary stem yield and fiber percentage and lead to fiber yield rising.展开更多
Winter fiber flax has been planted in a large area in Yunnan Province, the southwestern part of China, and other areas of the world, but little is known about the influence of fertilization on the fiber yield and qual...Winter fiber flax has been planted in a large area in Yunnan Province, the southwestern part of China, and other areas of the world, but little is known about the influence of fertilization on the fiber yield and quality. For that, a two-factor experiment in random block designed was carried out by specifying nitrogen (N), phosphorus (P) and potassium (K) as factor A, boron (B), manganese (Mn), copper (Cu), zinc (Zn) and molybdenum (Mo) as factor B each in four levels and their complete combinations. With the increase of N, P and K fertilizers, the yields of long-fiber and total-fiber obviously increased resulting from the increased straw yield, although the portion of retted-stem in straw, contents of longfiber and total-fiber decreased. The fiber tensile strength and flexibility increased as well. The micronutrients application increased the yields of straw, long-fiber and total-fiber, but gave no influence to fiber content and the fiber qualities. Combinations of the macronutrients and micronutrients gave obvious influences to the yields of straw and fiber, contents of long-fiber and total-fiber, fiber fineness and tensile strength, but little influence to the fiber flexibility. The fertilizers formula A2B2, i.e. N-P2O5-K2O 172.8, 28.8 172.8 kg/hm2, Zn-Cu-B-M-Mo 2363, 1654, 236, 2363,165 g/hm2, was the best, yielding most in the straw, long-fiber and total-fiber, with synchronous improvement of the three quality indices.展开更多
This study demonstrated that Bacillus licheniformis HDYM-03 and Bacillus megaterium HDYM-09, isolated from a liquid sample of fl ax retting pool, were able to produce pectinolytic enzymes using polysaccharides as subs...This study demonstrated that Bacillus licheniformis HDYM-03 and Bacillus megaterium HDYM-09, isolated from a liquid sample of fl ax retting pool, were able to produce pectinolytic enzymes using polysaccharides as substrates. Bacillus megaterium HDYM-09 produced pectin lyase that exhibited the highest activity of 2116.71 ± 11.55 U/mL. Bacillus licheniformis HDYM-03 produced pectate lyase that exhibited the highest activity of 611.21 ± 14.54 U/mL. Based on these fi ndings, we constructed four retting systems to degrade the pectin substance. The results showed that the content of galacturonic acid in the mixed system was 529.21 μg/mL, the content of reducing sugar was 98.14 mg/mL, and the weight loss ratio of cells reached 19.49%, which were signifi cantly higher than those in other systems. The mixed system has more advantages, and the utilization rate of degumming was higher, which further ensured that the degumming can be carried out effi ciently and quickly. The mixed system exhibits feasible applications in the fi ber and textile industry.展开更多
The present work is focused on better understanding of the interfacial interactions of SBA-15 mesoporous silica particles with flax fibers. In order to overcome the inherent complexity of flax fiber surface compositio...The present work is focused on better understanding of the interfacial interactions of SBA-15 mesoporous silica particles with flax fibers. In order to overcome the inherent complexity of flax fiber surface composition we have prepared model polysaccharide surfaces representing the main component of the flax fibers, e.g. cellulose, polygalacturonic acid (PGUA), and xyloglucan (XG) with thicknesses of about 200 nm, 100 nm, and 110 nm, respectively. The ξ-potential measurements of both silica and polysaccharides were performed in aqueous solutions as a function of pH and ionic strength. ξ-potential, AFM and SEM results supported the important role of electrostatic interactions in the silica adsorption on polysaccharide surfaces, since silica adsorption increased remarkably with ionic strength. The adsorption density of the SBA-15 onto the various polysaccharides was Cellulose > PGUA > XG, and the maximum was observed at pH = 4. Urea used as hydrogen bonds breaker reduced significantly the adsorption of SBA-15 on the polysaccharide surfaces, which highlighted the significant contribution of hydrogen bonding in the adsorption process. It was observed that most adsorbed SBA-15 particles were resistant to ultrasonic washing, which revealed their strong irreversible adsorption. Finally, direct adsorption experiments on both raw and treated real flax fibers yielded results consistent with those of model surfaces showing the important role of the surface fibers treatments on the improvement of the interfacial adhesion of the silica particles with flax fibers. The remarkable affinity of the SBA-15 particles with treated flax fibers is encouraging to design superinsulators composites with tuneable mechanical performances.展开更多
基金supported by the Natural Science Foundation of China(Grant No.31600459)the Natural Science Foundation of Heilongjiang Province of China(Grant No.C2016001)
文摘Flax fiber(FF) was used to reinforce wood flour/high density polyethylene composites(WF/PE).WF/PE particles were uniformly mixed with FF via high-speed mixing and then extruded with a single screw extruder to prepare FF reinforced WF/PE composites(FF/WF/PE).Mechanical testing,dynamic mechanical analysis,scanning electron microscopy(SEM),creep measurement and Torque rheology were used to characterize the resulting composites.The results indicate that the mechanical performance of the composites could be remarkably improved by adding a limited amount of FF.The flexural strength and modulus increased by 14.6 and 51.4%,respectively(FF content of 9 wt%),while the unnotched impact strength could be increased by 26.5%(FF content of12 wt%).The creep resistance and toughness of thecomposite was markedly improved without changing the plastic content of the composite material.
基金supported by the Natural Science and Engineering Research Council of Canada,the Canada Foundation for Innovation(CFI)(36668)the Canada Research Chairs Program(CRC),the Western Diversification Program(Canada)(15269)the Petroleum Technology Research Centre.
文摘The large number of oily wastewater discharges and oil spills are bringing about severe threats to environment and human health.Corresponding to this challenge,a functional PAA-ZnO-HDTMS flax fiber with UV-induced switchable wettability was developed for efficient oil-water separation in this study.The developed flax fiber was obtained through PAA grafted polymerization and then ZnO-HDTMS nanocomposite immobilization.The as-prepared PAA-ZnO-HDTMS flax fiber was hydrophobic initially and could be switched to hydrophilic through UV irradiation.Its hydrophobicity could be easily recovered through being stored in dark environment for several days.To optimize the performance of the PAA-ZnO-HDTMS flax fiber,the effects of ZnO and HDTMS concentrations on its switchable wettability were investigated.The optimized PAA-ZnO-HDTMS flax fiber had a large water contact angle(∼130°)in air and an extremely small oil contact angle(∼0°)underwater initially.After UV treatment,the water contact angle was decreased to 30°,while the underwater oil contact angle was increased to more than 150°.Based on this UV-induced switchable wettability,the developed PAA-ZnO-HDTMS flax fiber was applied to remove oil from immiscible oil-water mixtures and oil-in-water emulsion with great reusability for multiple cycles.Thus,the developed flax fiber could be further fabricated into oil barrier or oil sorbent for oil-water separation,which could be an environmentally-friendly alternative in oil spill response and oily wastewater treatment.
文摘The aim of this study is to show the interest of the mechanical and dynamical properties of glass-flax hybrid composites.Therefore,various staking sequences of glass-flax hybrid composites were manufactured and tested in free vibrations.The damping coefficients were identified by fitting the experimental responses of free-free bending vibrations.The obtained results show that the staking sequences and the position of flax fiber layers in the hybrid composites changed the properties,so a classification of different stacking sequences was established.In fact,the hybrid laminate made of two glass external layers placed on both sides of four flax layers is very interesting in term of its mechanical and damping properties.Indeed,it showed better specific bending modulus and loss factor than glass composites with proportions of 31 and 39%,respectively.A study of a structure of this composite has been made to validate the obtained results.
文摘Flax and hemp fibers were used as reinforcing materials to commingle with polypropylene(PP)fiber to realize the mixture of two materials at the stage of yarn.Meanwhile,PP filaments were introduced to produce a core-spun yarn with flax/PP as core and PP filament as outer sheath.The commingled yarns were woven into 2D fabric which was used as the prefabricated material.The composite laminates were prepared by hot press technology.The effects of manufacture technology,yarn structure,and fiber weight fraction on flexural properties of composites were investigated.
文摘The effecf of potassium fertilizer on Nitrate Reductase Activity (NRA), Hydrogen Peroxide Activity (HPA),Peroxidase Activity (PODA) in the fiber flax was studied on campus of NEAU in 1995 and 1996. The result showed that the changing of NRA,HPA and PODA was same in the period from the quick growth to blossom period in the different treamets. NAR and HPA was the highest in the quick growth period then cut down gradually,and PODA was just right contrary. The other side,it was obviously different to NRA, HPA and PODA in the different Potassium levels. NRA and HPA presented the highest enzyme activity in the trea- ment of K2O 22.5kg·ha-1 PODA in creased gradually with the increase of Potassium. PODA was the high- est in the treament of K2O 67.5kg·ha-1. But all of the Potassium treatments was higher than CK whatever NRA,HPA and PODA. Potassium may enhanced the primary stem yield and fiber percentage and lead to fiber yield rising.
文摘Winter fiber flax has been planted in a large area in Yunnan Province, the southwestern part of China, and other areas of the world, but little is known about the influence of fertilization on the fiber yield and quality. For that, a two-factor experiment in random block designed was carried out by specifying nitrogen (N), phosphorus (P) and potassium (K) as factor A, boron (B), manganese (Mn), copper (Cu), zinc (Zn) and molybdenum (Mo) as factor B each in four levels and their complete combinations. With the increase of N, P and K fertilizers, the yields of long-fiber and total-fiber obviously increased resulting from the increased straw yield, although the portion of retted-stem in straw, contents of longfiber and total-fiber decreased. The fiber tensile strength and flexibility increased as well. The micronutrients application increased the yields of straw, long-fiber and total-fiber, but gave no influence to fiber content and the fiber qualities. Combinations of the macronutrients and micronutrients gave obvious influences to the yields of straw and fiber, contents of long-fiber and total-fiber, fiber fineness and tensile strength, but little influence to the fiber flexibility. The fertilizers formula A2B2, i.e. N-P2O5-K2O 172.8, 28.8 172.8 kg/hm2, Zn-Cu-B-M-Mo 2363, 1654, 236, 2363,165 g/hm2, was the best, yielding most in the straw, long-fiber and total-fiber, with synchronous improvement of the three quality indices.
基金supported by the National Natural Science Foundation of China (Nos. 31270534, 31770538)the National Natural Science Youth Foundation of China (No. 31300355)the Post-Doctorate Foundation of Heilongjiang Province (No. LBH-Z15214)
文摘This study demonstrated that Bacillus licheniformis HDYM-03 and Bacillus megaterium HDYM-09, isolated from a liquid sample of fl ax retting pool, were able to produce pectinolytic enzymes using polysaccharides as substrates. Bacillus megaterium HDYM-09 produced pectin lyase that exhibited the highest activity of 2116.71 ± 11.55 U/mL. Bacillus licheniformis HDYM-03 produced pectate lyase that exhibited the highest activity of 611.21 ± 14.54 U/mL. Based on these fi ndings, we constructed four retting systems to degrade the pectin substance. The results showed that the content of galacturonic acid in the mixed system was 529.21 μg/mL, the content of reducing sugar was 98.14 mg/mL, and the weight loss ratio of cells reached 19.49%, which were signifi cantly higher than those in other systems. The mixed system has more advantages, and the utilization rate of degumming was higher, which further ensured that the degumming can be carried out effi ciently and quickly. The mixed system exhibits feasible applications in the fi ber and textile industry.
文摘The present work is focused on better understanding of the interfacial interactions of SBA-15 mesoporous silica particles with flax fibers. In order to overcome the inherent complexity of flax fiber surface composition we have prepared model polysaccharide surfaces representing the main component of the flax fibers, e.g. cellulose, polygalacturonic acid (PGUA), and xyloglucan (XG) with thicknesses of about 200 nm, 100 nm, and 110 nm, respectively. The ξ-potential measurements of both silica and polysaccharides were performed in aqueous solutions as a function of pH and ionic strength. ξ-potential, AFM and SEM results supported the important role of electrostatic interactions in the silica adsorption on polysaccharide surfaces, since silica adsorption increased remarkably with ionic strength. The adsorption density of the SBA-15 onto the various polysaccharides was Cellulose > PGUA > XG, and the maximum was observed at pH = 4. Urea used as hydrogen bonds breaker reduced significantly the adsorption of SBA-15 on the polysaccharide surfaces, which highlighted the significant contribution of hydrogen bonding in the adsorption process. It was observed that most adsorbed SBA-15 particles were resistant to ultrasonic washing, which revealed their strong irreversible adsorption. Finally, direct adsorption experiments on both raw and treated real flax fibers yielded results consistent with those of model surfaces showing the important role of the surface fibers treatments on the improvement of the interfacial adhesion of the silica particles with flax fibers. The remarkable affinity of the SBA-15 particles with treated flax fibers is encouraging to design superinsulators composites with tuneable mechanical performances.
