The novel alginate/N‐succinyl‐chitosan antibacterial blend fibers

Alginate/ N‐Succinyl‐chitosan (SCS) blend fibers, prepared by spinning their mixture solution through a viscose‐type spinneret into a coagulating bath containing aqueous CaCl₂, were studied for structure and properties with the aid of infrared spectroscopy (IR) and X‐ray diffraction (XRD). The results indicated a good miscibility between alginate and SCS, because of the strong interaction from the intermolecular hydrogen bonds. The best values of the dry tensile strength and breaking elongation were obtained when SCS content was 30 wt %. The wet tensile strength decreased with the increase of SCS content, and the wet breaking elongation achieved maximum value when the SCS content was 30 wt %. Introduction of SCS in the blend fiber improved water‐retention properties of blend fiber compared to pure alginate fiber. Antibacterial fibers, obtained by treating the fibers with aqueous solution of silver nitrate, exhibited good antibacterial activity to Staphylococcus aureus. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation and characterization of chitosan/poly(vinyl alcohol) blend fibers

Chitosan and poly(vinyl alcohol) blend fibers were prepared by spinning their solution through a viscose‐type spinneret at 25°C into a coagulating bath containing aqueous NaOH and ethanol. The influence of coagulation solution composition on the spinning performance was discussed, and the intermolecular interactions of blend fibers were studied by infrared analysis (IR), X‐ray diffraction (XRD), and scanning electron micrograph (SEM) and by measurements of mechanical properties and water‐retention properties. The results demonstrated that the water‐retention properties and mechanical properties of the blend fibers increase due to the presence of PVA in the chitosan substract, and the mechanical strength of the blends is also related to PVA content and the degree of deacetylation of chitosan. The best mechanical strength values of the blend fibers, 1.82 cN/d (dry state) and 0.81 cN/d (wet state), were obtained when PVA content was 20 wt % and the degree of deacetylation of chitosan was 90.2%. The strength of the blend fibers, especially wet tenacity could be improved further by crosslinking with glutaraldehyde. The water‐retention values (WRV) of the blend fibers were between 170 and 241%, obviously higher than pure chitosan fiber (120%). The structure analysis indicated that there are strong interaction and good miscibility between chitosan and poly(vinyl alcohol) molecular resulted from intermolecular hydrogen bonds. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2558–2565, 2001     

Preparation and characterization of alginate/gelatin blend fibers

Alginate and gelatin blend fibers were prepared by spinning their solution through a viscose‐type spinneret into a coagulating bath containing aqueous CaCl₂ and ethanol. The structure and properties of the blend fibers were studied with the aid of infrared spectra, scanning electron micrography, X‐ray diffraction, and thermogravimetric analysis. Mechanical properties and water‐retention properties were measured. The best values of the tensile strength and breaking elongation of blend fibers were obtained when gelatin content was 30 wt %. The water‐retention values of blend fibers increase as the amount of gelatin is raised. The structural analysis indicated that there was strong interaction and good miscibility between alginate and gelatin molecules resulted from intermolecular hydrogen bonds. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1625–1629, 2005     

再生羽毛蛋白纤维的研制

介绍了再生羽毛蛋白纤维的纺制工艺,对纺制纤维的理、化性能进行了测试分析,结果显示：采用氧化法制取羽毛角蛋白原液,纺丝原液中纤维素、蛋白质比例6∶4,碱的质量分数为3%,纺丝液黏度为40～60 s时,纺制出的再生羽毛蛋白纤维（2.7 dtex）干强为2.1 cN/dtex,湿强为1.8 cN/dtex,初始模量为33 cN/dtex,回潮率为13.8%,具有优良的强伸性及吸湿透汽性,同时对皮肤具有很好的亲和力。     

Influence of process parameters on the structure formation of man‐made cellulosic fibers from ionic liquid solution

The influence of dry‐jet wet spinning parameters on the production of man‐made cellulosic fibers from 13 wt % cellulose/1,5‐diazabicyclo[4.3.0]non‐5‐ene acetate solutions was investigated. The spinneret nozzle diameter, extrusion velocity, draw ratio, and coagulation bath temperature were the studied parameters. The production of highly oriented fibers was favored by selecting higher extrusion velocity and lower spinneret diameter. A spinneret size of 100 µm and a draw ratio of 6 were sufficient to highly orient the cellulose macromolecules and achieve tenacities above 40 cN/tex (600 MPa). Total orientation assessed via birefringence measurement, tenacity, and Young's modulus values reached a plateau at a draw of 6 and no further development in properties was observed. A temperature of the aqueous coagulation bath of 15 °C slightly promoted greater orientation of the fibers by hampering structural changes of the cellulose macromolecules in the nascent solid fibers. Furthermore, the determination of the elongational viscosity of the liquid thread via the measurement of radial force tensor was tested and showed promising results. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43718.     

Dry jet‐wet spinning of bagasse/N‐methylmorpholine‐N‐oxide hydrate solution and physical properties of lyocell fibres

Sugarcane bagasse, a cheap cellulosic waste material, was investigated as a raw material for producing lyocell fibers at a reduced cost. In this study, bagasse was dissolved in N‐methylmorpholine‐N‐oxide (NMMO) 0.9 hydrate, and fibers were prepared by the dry jet‐wet spinning method with coagulation in an aqueous NMMO solution. The effects of NMMO in 0 to 50% concentrations on the physical properties of fibers were investigated. The coagulating bath contained water/NMMO (10%) solution produced fiber with the highest drawability and highest physical properties. The cross‐section morphology of these fibers reveals fibrillation due to the high degree of crystallinity and high molecular orientation. In the higher NMMO concentrated baths (30 to 50%), the prepared fibers were hollow inside, which could be useful to make highly absorbent materials. The lyocell fibers prepared from bagasse have a tensile strength of 510 MPa, initial modulus of 30 GPa, and dynamic modulus of approximately 41 GPa. These properties are very comparable with those of commercial lyocell fibers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

竹笋壳纤维的力学性能

为了了解竹笋壳纤维的基本力学性能,为竹笋壳纤维的进一步开发利用提供理论依据,研究了竹笋壳纤维拉伸断裂性能、松弛性能和定伸长弹性性能等力学指标。结果表明,竹笋壳纤维断裂性能指标拉伸断裂强度、初始模量和断裂伸长率分别为3．21cN／dtex、214．32cN／dtex和2．01％,在湿态下竹笋壳纤维的拉伸断裂强度和初始模量下降较大,分别下降了38．6％和33．1％,断裂伸长率变化不大;比较干、湿态下竹笋壳纤维的抗应力松弛性能和定伸长抗伸回弹性,湿态下的抗应力松弛性能和弹性能力较优。     

Properties of fibers produced from soy protein isolate by extrusion and wet-spinning

Fibers were produced from soy protein isolate by both wet-spinning and extrusion. In the wet-spinning process, aged, alkaline protein solution was forced through a spinnerette into an acid coagulating bath. In the extrusion process, a twinscrew extruder forced a protein isolate-water mixture through a die. The physical properties of the fibers were measured at various water activities. The fibers produced by both methods were brittle and lacked tensile strength (tenacity). The addition of glycerol reduced brittleness in extruded fibers. Zinc and calcium ions decreased the brittleness of wet-spun fibers. The tenacity of soy fibers was significantly improved by post-spinning treatments, including acetic anhydride, acetaldehyde, glyoxal, glutaraldehyde, a combination of glutaraldehyde and acetic anhydride, and stretching. The best extruded fibers were produced with a mixture of 45% soy protein, 15% glycerol, and 40% water, finished with a combination of glutaraldehyde and acetic anhydride and then stretched to 150% their original lengths. The best wet-spun fibers were produced with a 19.61% soy protein suspension at pH 12.1; coagulated in a 4% hydrochloric acid solution that contained 3.3% sodium chloride, 3.3% zinc chloride, and 3.3% calcium chloride; and followed by treatment with 25% glutaraldehyde and stretching to 170% their original lengths.     

Adhesion and Physicochemical Properties of Soy Protein Modified by Sodium Bisulfite

Soy protein adhesives with a high solid content (28–39 %) were extracted from soy flour slurry modified with sodium bisulfite (NaHSO₃) at different concentrations. 11S‐dominated soy protein fractions (SP 5.4) and 7S‐dominated soy protein fractions (SP 4.5) were precipitated at pH 5.4 and pH 4.5, respectively. The objective of this work was to study the effects of NaHSO₃ on adhesion and physicochemical properties of soy protein. The adhesion performance of NaHSO₃‐modified SP 4.5 was better than SP 5.4; the wet strength of these two fractions was from 2.5 to 3.2 MPa compared with 1.6 MPa of control soy protein isolate. SDS‐PAGE results revealed the reducing effects of NaHSO₃ on soy protein. The isoelectric pH of soy protein decreased as NaHSO₃ increased due to the induced extra negative charges (RS‐SO₃^?) on the protein surface. The rheological properties of soy protein adhesives were improved significantly. Unmodified samples SP 5.4 and SP 4.5 had clay‐like properties and extremely high viscosity, respectively; with 2–8 g/L NaHSO₃ modification, both SP 5.4 and SP 4.5 had a viscous cohesive phase with good flowability. Overall, NaHSO₃‐modified soy protein adhesives in our study have many advantages over the traditional soy protein isolate adhesive such as better adhesion performance, higher solid content but with good flowability and longer shelf life.     

Dry‐jet‐wet spun polyurethane fibers. I. Optimization of the spinning parameters

This study examined the spinning of polyurethane‐based elastomeric fibers with the dry‐jet‐wet spinning method. The three important spinning variables that were chosen were the coagulation bath ratio (dimethylformamide/water), the bath temperature, and the stretch ratio. A three‐variable factorial design method, proposed by Box and Behnken, was used to optimize these process parameters. The spinning process was further fine‐tuned by the variation of the stretch ratio and the dope solid content. The effect of the dry‐jet length on the fiber properties was also studied. The tenacity and elastic recovery properties of the fibers were found to be optimum at a bath ratio (dimethylformamide/water) of 60 : 40, a bath temperature of 15°C, and a stretch ratio of 2.5. The density and sonic modulus were measured to determine the effect of varying the process variables on structural parameters such as the density and orientation. The surface morphological features, as revealed by scanning electron microscopy, were correlated to the fiber properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Study of the coagulated structure and fiber strength with wet spinning of aliphatic polyketone with aqueous composite metal salt solutions

Poly(1‐oxotrimethylene) (ECO) was dissolved in aqueous calcium chloride (CaCl₂)/zinc chloride (ZnCl₂) composite metal salt solutions, and the solutions had phase‐separation temperatures greater than 0°C. A higher proportion of CaCl₂ with respect to ZnCl₂ increased the phase‐separation temperature of the ECO solutions. When wet spinning was carried out with a coagulation bath at 2°C, an ECO solution with a higher phase‐separation temperature tended to produce greater ECO fiber strength. Therefore, a higher phase‐separation temperature resulted in coagulated filaments with a denser and more homogeneous cross‐sectional structure. When the metal salt concentration of the coagulation bath was increased with an ECO solution with a phase‐separation temperature of 22°C and a coagulation‐bath temperature of 2°C, the strength of the ECO fibers tended to be lower. Although little difference was observed in the uniformity of the fiber cross sections, a higher metal salt concentration in the coagulation bath facilitated greater spherical growth of the coagulated particles. Large, spherical coagulated particles promoted defects during drawing and thus lowered the strength of the ECO fibers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1250–1258, 2005     

Investigation the jet stretch in PAN fiber dry‐jet wet spinning for PAN‐DMSO‐H2O system

The jet stretch of dry‐jet wet spun PAN fiber and its effects on the cross‐section shape of fibers were investigated for a PAN‐DMSO‐H₂O system. Clearly, the spinning parameters, such as dope temperature, bath concentration, bath temperature, and air gap, all influenced the jet stretch. Also, under uniform conditions, the postdrawing ratio as well as that of jet stretch changed. Under given conditions, as the bath temperature was below 30°C or above 45°C, jet stretch had little effect on the cross‐sectional shapes of PAN fiber. Within the temperature of 30–45°C, fiber's cross‐section shapes change obviously from round over an approximate circular shape into to an elliptical or a flat shape. The scope of jet stretch produced PAN fiber with circular cross‐section was bigger than that in wet spinning. These results indicated that appropriate air gap height, under milder formation conditions in dry‐jet wet spinning, could result in higher jet stretch and higher postdrawing ratio. The appropriate jet stretch and postdrawing ratio could result in circular profile of PAN fiber, which were helpful to produce round PAN precursor with finer size and better properties for carbon fiber. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Fibers from urea–formaldehyde resins

The preparation of fibers from aqueous urea–formaldehyde resins has been investigated; a dry spinning process has been developed based on the extrusion of catalyzed resin into a drying chamber at 180–220°C, producing a multifilament yarn at spinning speeds of up to 600 m/min. A range of UF filaments was produced with diameters between 10–70 μm; the tenacities of spun filaments were 6–10 cN/tex, initial moduli were 220–340 cN/tex, and elongation at break was 4–10%. The best tensile properties resulted from conditions that produced the smallest diameter fibers. Postspin heat treatment improved the tenacity to 14 cN/tex and the elongation to 20%. Spinnability improved with increased viscosity of the spinning solution and increased cell temperature, while tenacity and elongation increased with increasing cell temperature and spinning stretch. A correlation was found between TGA weight loss (between 105 and 200°C) and fiber tenacity. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 64–74, 2000     

Processing,structure, and properties of gel spun PAN and PAN/CNT fibers and gel spun PAN based carbon fibers

Polyacrylonitrile (PAN) and PAN/carbon nanotube (PAN/CNT) fibers were manufactured through dry‐jet wet spinning and gel spinning. Fiber coagulation occurred in a solvent‐free or solvent/nonsolvent coagulation bath mixture with temperatures ranging from ?50 to 25°C. The effect of fiber processing conditions was studied to understand their effect on the as‐spun fiber cross‐sectional shape, as well as the as‐spun fiber morphology. Increased coagulation bath temperature and a higher concentration of solvent in the coagulation bath medium resulted in more circular fibers and smoother fiber surface. as‐spun fibers were then drawn to investigate the relationship between as‐spun fiber processing conditions and the drawn precursor fiber structure and mechanical properties. PAN precursor fiber tows were then stabilized and carbonized in a continuous process for the manufacture of PAN based carbon fibers. Carbon fibers with tensile strengths as high as 5.8 GPa and tensile modulus as high as 375 GPa were produced. The highest strength PAN based carbon fibers were manufactured from as‐spun fibers with an irregular cross‐sectional shape produced using a ?50°C methanol coagulation bath, and exhibited a 61% increase in carbon fiber tensile strength as compared to the carbon fibers manufactured with a circular cross‐section. POLYM. ENG. SCI., 55:2603–2614, 2015. © 2015 Society of Plastics Engineers     

Chitin nanocrystal reinforced wet‐spun chitosan fibers

Chitosan (CS) has been extensively studied and found wide applications in the field of biomedicine because of its favorable biological properties. Normal CS fibers are manufactured either by wet‐spinning or by dry‐jet wet‐spinning. However, the poor tensile strength of CS fibers raises much concern. The present study uses chitin nanocrystal (ChiNC), a stiff rod‐like nanofiller, to enhance the mechanical properties of wet‐spun CS fibers. Owing to the good compatibility between CS and ChiNC, the nanoparticles are well distributed in the CS matrix. When the ChiNCs loading is 5 wt %, the optimal mechanical properties of CS fibers are obtained, and the peak stress is 2.2 cN/dtex and modulus is 145.6 cN/dtex, which are increased by 57% and 84.5%, respectively, compared to that of nonfilled CS fibers under the same processing condition. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40852.     

Physical properties of poly(vinyl alcohol) fibers prepared from wet spinning/multi-step drawing

The preparation of poly(vinyl alcohol) (PVA) fibers by multi-step drawing was examined. The high draw ratio was attained when the drawing just before melting point was repeated. The influences of the draw ratio on mechanical and thermal properties of the fibers were studied. We utilized the wide angle x-ray diffraction (WAXD) as a medium to observe the erystallinity and the orientation of PVA fibers to study their effects on the physical properties of the fibers. With various coagulation bath concentration, both the tenacity and Young's modulus of fibers would increase as the draw ratios increased, the elongation would decrease at the same time. The tenacity was able to reach 41.0 cN/tex with the Young's modulus being 856.2 cN/tex; also, as the draw ratios increased, both crystallinity and orientation would increase. The crystallinity was about 67.2 % and the orientation was about 86.4%.     

用于与羊毛混纺的低温可染聚酯纤维性能研究

研究了常规涤纶 (NPET)和两种常压可染改性涤纶 (EDDP、ECDP)的力学性能、热性能、结晶性能等 ,并与羊毛进行了比较。结果表明 ,EDDP、ECDP的断裂强度分别为 3 4.8c N/tex和 3 0 .6c N/tex,明显低于 NPET。EDDP的断裂伸长达 5 9.4% ,明显大于 N PET及 ECDP。EDDP和 ECDP的含水率分别为 1.0 1%和 1.2 8% ,明显高于常规涤纶 ,但仍远低于羊毛。两种改性涤纶的热稳定性劣于NPET。与 NPET和 ECDP相比 ,EDDP具有较高的结晶速率。经 160～ 180℃热定型后 ,改性涤纶的 Tg比常规涤纶 Tg低约 10℃ ,干热收缩率则高于常规涤纶。     

New class of cellulose fiber spun from the novel solution of cellulose by wet spinning method

A novel cellulose solution, prepared by dissolving an alkali-soluble cellulose, which was obtained by the steam explosion treatment on almost pure natural cellulose (soft wood pulp), into the aqueous sodium hydroxide solution with specific concentration (9.1 wt %) was employed for the first time to prepare a new class of multifilament-type cellulose fiber. For this purpose a wet spinning system with acid coagulation bath was applied. The mechanical properties and structural characteristics of the resulting cellulose fibers were compared with those of regenerated cellulose fibers such as viscose rayon and cuprammonium rayon commercially available. X-ray analysis shows that the new cellulose fiber is crystallographically cellulose II, and its crystallinity is higher but its crystalline orientation is slightly lower than those of other commercial regenerated fibers. The degree of breakdown of intramolecular hydrogen bond at C₃[X_am(C₃)] of the cellulose fiber, as determined by solid-state cross-polarization magic-angle sample spinning (CP/MAS) ¹³C NMR, is much lower than other, and the NMR spectra of its dry and wet state were significantly different from each other, indicating that cellulose molecules in the new cellulose fiber are quite mobile when wet. This phenomenon has not been reported for so-called regenerated cellulose fibers.     

Preparation and characterization of alginate/Hydroxypropyl chitosan blend fibers

Hydroxypropyl chitosan (HPCS) was synthesized from chitosan and propylene oxide under alkali conditions. It was characterized by IR spectroscopy and X-ray diffraction (XRD). We prepared alginate/HPCS blend fibers by spinning their solution through a viscose-type spinneret into a coagulating bath containing aqueous CaCl₂ and ethanol. The structure and properties of the blend fibers were studied with the aid of IR spectroscopy, scanning electron microscopy, and XRD. The results indicate a good miscibility between alginate and HPCS because of the strong interaction of the intermolecular hydrogen bonds. The mechanical properties and water-retention properties were also measured. The best values of the tensile strength and breaking elongation of the blend fibers were obtained when the HPCS content was 30 wt %. The water-retention values of the blend fibers increased as the amount of HPCS increased. Antibacterial fibers, obtained by the treatment of the fibers with an aqueous solution of silver nitrate, exhibited good antibacterial activity to Staphylococcus aureus. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

海藻酸钙/纳米TiO_2共混纤维的制备与表征

将含固体质量分数为5%的海藻酸钠纺丝原液与纳米二氧化钛(TiO2)水分散液均匀混合,制得海藻酸钠/纳米TiO2混合纺丝原液,采用湿法纺丝,通过氯化钙凝固浴,经拉伸、水洗,制备了海藻酸钙/纳米TiO2共混纤维,研究了纳米TiO2含量对共混纤维结构及性能的影响。结果表明:纳米TiO2的加入,提高了共混纤维的力学性能;加入质量分数为0.5%的纳米TiO2,海藻酸钙大分子链上的红外特征吸收峰峰形明显变宽,共混纤维的力学性能最佳,断裂强度为2.93 cN/dtex,断裂伸长率为7.34%,优于海藻酸钙纤维;添加纳米TiO2质量分数为3%时,纳米TiO2在共混纤维中仍能较好的分散,且纤维表面光滑。加入纳米TiO2后,共混纤维的热稳定性提高。