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The raw material of polylactide (PLA) is lactic acid obtained by biological fermentation. PLA is the most promising degradable polymer to replace traditional plastics to address the pollution problems caused by their non-degradability. However, the application of PLA is hindered by its low softening temperature, easy hydrolysis, and poor toughness. Herein, the ternary composites with PLLA, PDLA and Poly (butylene adipate-co-terephthalate) (PBAT) were prepared by melt blending to balance its thermal stability, hydrolysis, and toughness. The effects of PBAT content (3 %, 6 %, 9 % and 12 %) and isothermal crystallization temperature on composite properties were fully investigated. The results show that the composite of stereo-complexed PLA (sc-PLA) with 6 % PBAT crystallized at 110 °C exhibits good comprehensive properties. Its vicat softening temperature (VST), mass loss rate under alkaline (pH = 12) and breaking elongation are 166 °C, 21.6 % and 4.40 %, respectively. Compared with the pure PLLA sample crystallized at same condition, the VST, mass loss rate and breaking elongation are 159 °C, 24.7 % and 3.76 % respectively, which increased by nearly 5 %, 13 % and 20 %. This indicates that this strategy is feasible to balance the heat resistance, hydrolysis resistance and toughness of PLA, while it sacrifices the tensile strength a little. This work provides a new way to modify and improve the PLA properties. Nonetheless, it is also necessary to coordinate the compatibility of PLA and PBAT.

In this research, bio-based polyamide (bio-PA) was synthesized from dimethyl furan-2,5-dicarboxylate and 1,3-cyclohexanedimethanamine by melt polymerization. The properties of bio-PA were analyzed by Fourier transform infrared spectrometer (FTIR), nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA), respectively. The results show that this bio-PA presents high glass transition temperature (Tg) from 150°C to 180°C and poor crystallization due to the asymmetric rigid structure of cyclohexane and furan. Its molecular weight is low, ascribing to the large steric hindrance from cyclohexane and furan, and the side reaction of N-methylation and decarboxylation. Besides, the results of solubility reveal that this bio-PA can be dissolved in DMSO, DMF and DMAC.

In recent years, natural polymer-based electrospun fibers (EFs) with huge specific surface area, good biocompatibility, and biological activity obtained from electrospinning process exhibit tremendous vitality in the field of biomedical areas. Herein, the parameters of electrospinning from two perspectives, polymer solution such as solvent, polymeric relative molecular mass, concentration, viscosity, and conductivity of the solution, and electrospinning process such as spinning voltage, spinning flow rate, needle tip to collector distance, temperature, and humidity are first detailed. Next, the raw materials consisting of polysaccharides such as cellulose, hyaluronic acid, alginate, and chitosan as well as proteins such as collagen, gelatin, silk fibroin, and keratin are summarized. The preparation method and related characteristics of EFs with multistage structures such as porous, core-shell, Janus, bamboo-like and other structures are introduced. The biomedical applications of these natural polymer-based EFs mainly including tissue engineering, drug sustained release, wound dressings, and biomedical sensors are systematically recapitulated. Finally, the outlook on natural EFs is further proposed.

In this research, nanocellulose crystal (NCC) grafted with lactic acid (LA) oligomer was synthesized by one-pot method and used to reinforce the poly( l -lactic acid) (PLLA) matrix. FT-IR, XRD, and 13C NMR were used to analyze the structure of modified nanocellulose crystal (g-NCC). The results of GPC suggested that the degree of polymerization of the grafted segments was 23, and the degree of hydroxyl substitution of g-NCC was 2.4%. For the g-NCC/PLLA composite, its crystallization rate increases significantly compared with pure PLLA, indicating that g-NCC acted as a nucleating agent to promote the crystallization. Moreover, tensile strength of the composite materials was significantly improved from 41.9 MPa to 53.9 MPa due to the enhanced compatibility. This study provides a fast and effective modification method for g-NCC/PLLA biodegradable composites. According to the above-mentioned experimental results, the g-NCC/PLLA composites can be considered as a potential material in the packaging field, mainly due to its proper biological and physicochemical properties.

As a bio-based polyamide, PA56 is restricted in many fileds due to its flammability. In this research, flame-retardant PA56 copolymers (FRPA56s) were designed and successfully synthesized with the introduction of 9,10-dihydro-10-[2,3-di(hydroxy carbonyl)propyl]-10-phosphaphenanthrene-10-oxide (DDP) unit. The thermal properties, thermal degradation and flame behavior of the resultant copolymer were investigated by DSC, TGA, LOI, UL-94 and cone calorimeter tests, respectively. Compared to PA56, the peak value of heat release rate and total heat release of FRPA56 containing 1.2 mol% DDP decrease by 35 % and 19 %, respectively, indicating the high flame-retardant efficiency of DDP. It is also found that FRPA56 with only 1.0 mol% DDP passes V-0 grade in the UL-94 test while its thermal performance is almost the same as homopolymer PA56. The pyrolysis products in both the condensed and gas phases were further systematically analyzed by SEM, Raman, X-ray photoelectron spectroscopy and TGA-GC/MS. The flame-retardant mechanism was also proposed for FRPA56s.

In this study, polyacrylic acid modified filter paper (FP/PAA) was synthesized by in-situ polymerization of acrylic acid, which was used as a matrix to chelate nano-scale zero valent iron (nZVI). The loading content of nZVI in the filter paper reached 24.8%. The fabricated composite FP/PAA/nZVI was characterized by SEM, FT-IR and TGA respectively. Moreover, it was used for the removal of methyl blue and methylene blue as model anionic and cationic dyes. The effect of initial dye concentration on decolorization efficiency was investigated. The results showed that FP/PAA/nZVI enhanced the removal of dye from the simulated dye wastewater and the decolorization efficiency exceeded 95% for the dye solutions lower than 20 mg/L. More importantly, the filter paper supported nZVI realized the continuous treatment of simulated dye wastewater by a simple filtration process. This study hopes to serve as a basis for the application of nZVI in textile wastewater treatment.

This paper investigated the feasibility of enhancing the interface between lignocellulosic fibers and a polypropylene matrix via structure alteration of lignin at elevated temperatures. Alkali treatment can remove gum substances from lignocellulose fibers effectively at elevated temperatures but easily causes damages to fiber strength. In previous studies on directional delignification of lignocellulosic fibers, loss of fiber strength is avoided but condensation and degradation of lignin are accelerated. So far, few reports have been available on the effect of lignin structures on the interface between fibers and a matrix. In this study, jute fibers with different lignin structures are produced at 100 and 130 &deg, C for reinforcing a polypropylene matrix. The interface between the fibers and matrix is analyzed. The result shows that decrease in aliphatic hydroxyl concentration by 9.5% at 130 &deg, C from 3 to 5 h contributes to a 14.2% decrease in the surface energy of jute fibers. Meanwhile, the polydispersity index of lignin decreases from 1.21 to 1.15. Centralized distribution of lignin molecule-weight and reduction in fiber surface energy improves the interface between the fibers and matrix, which manifests as a 30.8% increase in the impact strength of the composites. Similar improvement is not observed in the composites reinforced with jute fibers at 100 &deg, C, due to the absence of lignin-structure changes. This paper provides a new strategy to improve the interface between lignocellulose fibers and a hydrophobic matrix.

Ultrasound-microwave-assisted (UMA) extraction method with blended solvent 70% ethanol/30% water with HCl significantly improved extraction of biocolorants from sorghum husk. Sorghum is a staple food in many parts of the world. As the demand for the grain soars, there is an equivalent increase in quantity of sorghum husk generated. Sorghum husk is a promising source for natural functional dye. However, the phenolic colorants in sorghum husk are bound to the cell wall and are difficult to extract. This paper is focused on improving the extraction of natural dye from sorghum husk and investigating the effect of the extraction methods and solvents on the dyeing properties of sorghum husk extracts (SHE). UMA extraction method with blended solvent 70% ethanol/30% water with HCl (1 ml HCl per 100 ml) had a SHE yield of 16.7%, which was 3.6 times the yield of 4.6% by conventional shaking (CS) method with water as solvent. SHE extracted by the UMA method had high contents of apigeninidin as well as luteolinidin and higher thermal stabilities than SHE extracted with water. SHE with different solvents produced different shades when dyeing wool and cotton fabrics. SHE by 70% ethanol/30% water with or without HCI had similar dye strength and significantly higher dye strength compared to SHE extracted by water. The dyed wool and cotton fabrics had good colorfastness to laundry, crocking and light. UMA extraction with blended solvent 70% ethanol/30% water with HCI was an efficient method to extract dye from sorghum husk and provided the potential for industrial application. The use of sorghum husk as a source of industrial dye will significantly add value to the sorghum plant and reduce the disposal of sorghum husk.

A clean and cost-effective method for 100% stereo-complexation in polylactide (PLA) fibers with molecular weight (MW) as high as 6 × 105 demonstrates good potential for industrial-scale continuous manufacture. Polylactide, a widely recognized biodegradable and renewable biopolymer, has a negligible share of plastic markets due to its poor hydrolytic and thermal resistance. Stereo-complexation is effective in overcoming these challenges. However, current stereo-complexation approaches usually require solvents and/or external nucleation reagents, and are expensive and complicated. Moreover, high-MW PLAs favored for developing durable products are difficult to be stereo-complexed. In this research, enantiomeric PLAs both with MW up to 6 × 105 were completely stereo-complexed via a facile thermal treatment on pilot-scale devices. Neither solvent nor nucleation agent was used. For poly(L-lactide) (PLLA) fibers with MW of 6 × 105, percentage retention of MW and percentage retention of tensile strength after hydrolysis under simulated textile dyeing condition increased from 39% to 93% and from 20% to 89%, respectively, after complete stereo-complexation. The melting point, softening point and percentage retention of MW after hydrolysis of stereo-complexed PLA (sc-PLA) fibers were up to 51 °C, up to 59 °C and up to 183% higher than that of PLLA fibers with the same MW, respectively. The mechanism of thorough stereo-complexation in high-MW PLA fibers was proposed and verified. It is promising to use this approach to broaden industrial applications of renewable and degradable biopolymers for sustainable development of material industries.

One-hundred percent stereo-complexation in poly(l-lactide) (PLLA)/poly(d-lactide) (PDLA) fibers with non-equivalent molecular weights could be achieved via thermal treatment. Stereo-complexed polylactide (sc-PLA) fibers exhibited excellent hydrolysis resistance and thermal resistance. Till now, preparation of sc-PLA fibers with satisfactory qualities required both PLLA and PDLA with equivalently high molecular weights. Moreover, the high-molecular-weight PDLAs are expensive, restricting industrial-scale production and applications of sc-PLA products. In this study, equal-weight mixtures of low-molecular-weight PDLA (L-PDLA) and high-molecular-weight PLLA (H-PLLA) were melt spun into sc-PLA fibers and then completely stereo-complexed via thermal treatment. The hydrolysis resistance of L3/D1 fibers [PLLA (Mv = 3.0 × 105)/PDLA (Mv = 1.0 × 105)] was similar to that of L3/D3 fibers [PLLA (Mv = 3.0 × 105)/PDLA (Mv = 3.2 × 105)], but much higher than that of L3 fibers [PLLA (Mv = 3.0 × 105)]. Melting temperature and softening temperature of L3/D1 fibers (223 and 126 °C) were also similar to those of L3/D3 fibers (224 and 131 °C), but higher than that of L3 fibers (172 and 72 °C). Utilizing H-PLLA and L-PDLA to prepare sc-PLA fibers with excellent performance is conducive to the wide industrial application of sc-PLA.

A facile and clean technology for stereo-complexation of polylactides (PLAs) shows potential to be readily incorporated into continuous industrial processes for manufacture of films, fibers and other plastic products. Using this approach, complete stereo-complexation of high-molecular-weight PLAs could be achieved via simple thermal treatment, rendering the production of durable PLA commodities inexpensive and industrially scalable. Currently, due to their high susceptibility to water and heat, PLA products have restricted industrial applications, and cannot compete with their petroleum-derived counterparts. Stereo-complexation of poly( l -lactic acid) (PLLA) and poly( d -lactic acid) (PDLA) could effectively decrease water and heat sensitivity of common PLLA products. However, many stereo-complexation processes required harmful solvents or nucleating agents, and thus, were costly, complicated, and had low potential for short-term industrialization. Moreover, complete stereo-complexation was mostly achieved for PLAs with weight-average molecular weight lower than 1 × 10 5 . In this research, PLLA and PDLA both with viscosity-average molecular weight of 3 × 10 5 were completely stereo-complexed (sc) via simple thermal treatment. Comparing to PLLA fibers, sc-PLA fibers had softening points 60 °C higher, and their thermal and hydrolytic stability significantly enhanced. Relationship among temperature of thermal treatment, degree of stereo-complexation and performance properties of sc-PLA fibers were also established. This clean technology makes possible industrial-scale production of commercializable biobased plastics.

We report a novel application of sorghum husk extracts (SHE) as a natural functional dye for wool fabrics. Sorghum husk is an abundant, cheap and readily available agricultural byproduct. A small proportion of sorghum husk has been used to extract food colorants. In order to add value to sorghum and decrease environmental pollution, a number of investigations need to be undertaken to explore newer application for the husk. This paper investigated the stability of SHE, the colorfastness, UV-protection and fluorescence properties of dyed wool fabrics with SHE by different dyeing methods. SHE had good thermal and pH stability suitable for the dyeing and finishing processes of textiles. Wool fabrics dyed directly or with Al3+ and Fe2+ mordant demonstrated good colorfastness to washing, to rubbing, to wet ironing and acceptable colorfastness to light. The dyed wool fabrics showed good UV-protection and fluorescence properties. After 30 home laundering cycles, the UV-Protection Factor (UPF) and fluorescence int...

In this study, composite membranes were prepared from mixed solution of polyvinylidene fluoride (PVDF) and cellulose via the non-solvent-induced phase separation (NIPS) method. N, N-dimethylacetamide (DMAc) and 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) were used as the solvent for PVDF and cellulose, respectively. SEM and in situ scanning techniques were used to investigate the morphology of the prepared membranes. The results showed that viscose cellulose/[Bmim]Cl solution acted as a porogenic agent during the membrane preparation process. Hydrophilicity of the composites was evaluated by water contact angle, moisture regain and equilibrium water uptake, which demonstrated that the wettability of the membranes was associated with the hydrophilic group and the roughness of the surface. Most importantly, the α → β transformation in PVDF matrix was demonstrated from the results of WAXD, FT-IR and DSC. The quantitative analysis indicated that the β-phase content in PVDF reached 90.1% when cellulose content was 5%, which is higher than many published references and was ascribed to the cooperation of cellulose and ionic liquid. Besides, the crystallinity, thermal stability and mechanical properties of the composite membranes were studied as well.

Natural extracts gallnut tannins (GTs) were used as functional components to prepare chitosan/gallnut tannins (CS/GTs) composite fiber by blended solution spinning. Chitosan fiber has great potential to be used as absorbent suture and dressing due to its good biocompatibility. However, the weak mechanical properties limited its application. Chitosan and GTs were blended in aqueous solution of acetic acid to spin the composite fiber. The results indicated that CS/GTs fiber can be easily prepared due to the appropriate rheology characteristics for blended solution. Compared with pure chitosan fiber, CS/GTs fiber with 10% GTs showed lower hydrophilicity and higher dry, wet breaking strength by more than 40% due to ionic cross-linking between chitosan and GTs. The bacterial reduction to Staphylococcus aureus increased from 49.0 to 99.7% and about double green and red fluorescent intensity were observed for CS/GTs fiber. GTs have great potentiality in improving the properties of chitosan fiber.

Without additional matrix or reinforcement, compression molded composites from waste polypropylene (PP) carpets/nylon (PA) carpets or PP carpets/polyester (PET) carpets have higher mechanical properties and sound absorption than traditional jute/PP composites. Large amount of carpets have been discarded every year, leading to waste of petro-based materials and serious environmental pollution. Fabrication of composites from discarded carpets via compression molding could save petroleum resources and alleviate environmental pressure. In this research, the compression molded composites from waste PP/PA carpets or PP/PET carpets showed good mechanical properties, sound absorption and water stability. Compared to the jute/PP composites, nylon 6,6 (PA66)/PP carpet composites had 37% and 9% higher flexural strength and impact resistance, as well as 45% and 10% higher sound absorption and water stability, indicating their potential for transportation and construction industries.

In this work, acidic ionic liquid glycine hydrochloride (Gly·HCl) is reported as a new solvent for dissolving chitosan. The regenerated chitosan fibers were fabricated by a wet spinning process and characterized by scanning electronic microscopy, fourier transform infrared spectroscopy, wide-angle X-ray diffraction and thermal gravimetric analysis. The result shows that the regenerated chitosan fibers had the same chemical structure as the raw chitosan flake, however, its thermal stability and crystallinity is a little low. Furthermore, a new mechanism of dissolving chitosan in ionic liquid was proposed. The chitosan fibers had soft feeling, excellent antibacterial property and have huge potential application in biomaterials.

Chicken feather, a potential source of keratin, is often disposed as waste material. Although some methods, i.e., hydrolysis, reduction, and oxidation, have been developed to isolate keratin for composites, it has been limited due to the rising environmental concerns. In this work, a green solvent N-methylmorpholine N-oxide (NMMO) was used to extract keratin from chicken feather waste. Eighty-nine percent of keratin was extracted using 75% NMMO solution. However, the result from size exclusion HPLC showed that most of the keratin degraded into polypeptide with molecular weight of 2189 and only 25.3% regenerated keratin was obtained with molecular weight of 14,485. Analysis of amino acid composition showed a severe damage to the disulfide bonds in keratin during the extraction procedure. Oxidization had an important effect on the reconstitution of the disulfide bonds, which formed a stable three-dimensional net structure in the regenerated keratins. Besides, Raman spectra, NMR, FT-IR, XRD, and TGA were used to characterize the properties of regenerated keratin and raw chicken feather. In the end, a possible mechanism was proposed based on the results.

The functionalizing nanoporous polyacrylonitrile-based oxidized membrane (PAN–OM) firmly immobilized with highly reactive nanoscale zero-valent iron (NZVI) are successfully prepared via an innovative in situ synthesis method. Due to the formation of ladder structure, the PAN–OM present excellent thermal and chemical stabilities as a new carrier for the in-situ growth of NZVI via firm chelation and reduction action, respectively, which prevent the aggregation and release of NZVI. The developed NZVI-immobilized membrane present effective decolorizing efficiency to both anionic methyl blue and cationic methylene blue with a pseudo-first-order decay and degrading efficiency to trichloroethylene (TCE). The regeneration and stability results show that NZVI-immobilized membrane system can be regenerated without obvious performance reduction, which remain the reactivity after half a year storage period. These results suggest that PAN-based oxidized membrane immobilized with NZVI exhibit significant potential for environmental applications.

Novel amphiphilic conetworks (APCNs) with uniform channel size were synthesized through end-cross-linking of well-defined amphiphilic triblock copolymers via atom transfer radical polymerization (ATRP). A new ditelechelic polydimethylsiloxane macroinitiator was synthesized to initiate the polymerization of N,N-dimethylacrylamide. The resulting triblock copolymers show well-defined molecular weight with narrow polydisperisty, which are telechelic modified by allylamine and fully cross-linked with polyhydrosiloxanes through hydrosilylation. Transmission electron microscopy shows that the APCN has the behavior of microphase separation with small channel size and uniform phase domain. The resulting APCNs with idealized microstructure exhibit a combination of excellent properties, i.e., superhigh mechanical strength (4 ± 1 MPa) and elongation ratio (175 ± 25%), outstanding oxygen permeability (350 ± 150 barrers), a high water uptake property, and excellent biocompatibility, indicating that in this way, "near perfect" networks are obtained. These results are better than those reported in the literature, suggesting a promising semipermeable barrier for islet encapsulation in relative biomaterial fields.

PVDF/SiO2 hybrid membranes with outstanding antifouling property were prepared from PVDF/glycerol triacetate system via thermally induced phase separation method, and characterized by scanning electron microscope, energy dispersive X-ray spectrometer analyses, differential scanning calorimeter, and wide angle X-ray diffraction. Their properties such as permeability, porosity, pore size distribution, and mechanical performance were also determined. The results show that SiO2 nanoparticles modified by 3-aminopropyltriethoxysilane can be uniformly dispersed in membranes due to improved compatibility between PVDF solution and nanoparticles. The addition of SiO2 particles to PVDF/glycerol triacetate mixture has a strong effect on crystallinity of the resulting hybrid membrane, which does not affect the type of PVDF crystal structure. Water flux recovery ratio is significantly increased from 11.7 % for pure PVDF membrane to 93.8 % for PVDF/SiO2 hybrid membrane with addition of 8 wt% modified SiO2. This remarkable promotion is related to the implantation of SiO2 nanoparticles into the inner surface of membrane, which effectively restrains the adsorption of bovine serum albumin on the pore walls and improves antifouling property of the final membranes. Additionally, pure water flux of the hybrid membrane is increased by 276 %, i.e., from 85 to 320 L m−2 h−1, tensile strength is increased by 26.5 %, and elongation at break is increased by 85.4 % compared with that of pure membrane.

Chitosan membrane possesses huge potential application in many fields, such as biomedicine, wastewater purification and environmental protection, however, the poor mechanical property restricts its further development. In this study, chitin whisker was prepared by hydrolysis method, and was firstly used as an interlayer to fabricate the multilayered chitosan membrane through layer-by-layer method, which is inspired by the natural materials' hierarchical structure. From the results of mechanical testing, it is shown that tensile strength of the multilayered chitosan membranes reaches up to 122.8 MPa, which is about 2.5 times than that of neat chitosan membrane (i.e. 49.5 MPa), and the elongation at break is sharply increased as well.

A binary ionic liquid system was confirmed to be a promising solvent to dissolve chitosan, and the regenerated chitosan fibers were prepared by wet and dry-wet spinning technique respectively. The SEM results show that the chitosan fibers prepared by wet spinning technique present striated surface and round cross section, and the chitosan fibers prepared by dry-wet spinning technique present smooth surface and irregular cross section. The mechanical testing results show that the regenerated chitosan fibers present relatively high tenacity, especially, these prepared by dry-wet spinning process present excellent strength and initial modulus, i.e. 2.1 cN/dtex and 83.5 cN/dtex, which is stronger than that of most reported chitosan fibers. The FT-IR results show that the dissolution of chitosan in the binary ionic liquid system is due to the protonation of NH 2 groups in the chitosan chains. Furthermore, a possible reaction during the dissolution and regeneration process is proposed.

Keratin particles with microscale are prepared by ball mill and its influences on the chitosan membrane is evaluated. Composite membranes with various content of keratin are fabricated, and their physical and chemical properties such as morphology, wettability, crystallization, thermal stability, tensile strength, and break elongation are investigated. Optical microscope and situ topographic scan mode of nano-test system are used to examine the dispersion and aggregation of keratin on the surface of chitosan membrane. The result of contact angle (CA) and mechanical testing show that the incorporation of keratin particles decrease the CA from 98.1 ° to 58.2 °. Tensile strength and break elongation of the composite membrane reaches a maximum of 65 ± 8 MPa and 15% when the keratin content is 6%, an increase of 80% and 88% compared with the pristine chitosan membrane. Both the increase in tensile strength and break elongation is result of the incorporation of keratin particles known for their excellent compatibility between keratin and chitosan matrix. These kind of composite material combines the antibacterial properties of chitosan with cell culture preference of keratin which may have potential biomedical application. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 134, 44667.

In the present study, regenerated cellulose membrane with “imprinted morphology” and low crystallinity was fabricated from the crystal cellulose/[Bmim]Cl solution. Spherulites of 1-butyl-3-methilimidazolium chloride ([Bmim]Cl) and cellulose/[Bmim]Cl solution were observed using polarized optical microscopy under certain condition. The fabricated cellulose membranes presented some particular characteristics compared with the membrane prepared from traditional cellulose/[Bmim]Cl solution. All the fabricated membranes were characterized by optical microscope, Wide-angle X-ray diffraction (WAXD), thermo-gravimetric analysis, and mechanical testing. The images showed that the resulting membranes prepared from crystal cellulose/[Bmim]Cl solution were “imprinted” with patterns which originated from the crystalline structure of [Bmim]Cl. The results of WAXD showed that the obtained cellulose membrane exhibited low diffraction peaks and crystallinity of approximately 24.57%. Furthermore, the low crystallinity led to the low mechanical property (27.5 MPa), thermal stability (315.4 °C), and high moisture regain (9.5%). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43798.

A binary system consisting of acidic ionic liquid glycine hydrochloride (Gly·HCl) and neutral ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) is proposed to be cosolvent for chitosan and cellulose, the spinning solution of chitosan/cellulose can be prepared in one step. The regenerated chitosan/cellulose composite fiber with 9.4 wt.% chitosan was prepared through dry–wet spinning process. SEM shows that the chitosan is scattered on the surface and interior of the composite fiber. WAXD shows that the degree crystallization of the composite fibers is far less than that of raw materials. The result of elemental analysis (EA) indicates that there is little weight loss of chitosan during the spinning process. Moreover, the prepared composite fiber presents good thermal stability, i.e. its T onset is 305.1 °C, and excellent mechanical property, i.e. its tensile strength is 4.63 cN/dtex. All the results show that Gly·HCl/[Bmim]Cl binary system is a promising solvent for the preparation of chitosan/cellulose composite fiber.

The focus of this article is the preparation and characterization of cellulose/chitin blend filaments obtained from cellulose/chitin xanthate blend solution over the experimental blend ratio, i.e., 2.89% and 6.46% (w/w) chitin content. The addition of chitin xanthate into cellulose xanthate leads to an increase of intermittence rate and the blend solution has good filtering property. Scanning electronic microscope photos shows that there exist grooves on the filaments surface, which are becoming coarse with increasing chitin content. The mechanical properties of the spun blend filaments is much higher than that of Crabyon® fiber, which proves that the viscose method we adopt here is an efficient way to prepare cellulose/chitin blend filaments with satisfactory mechanical properties and processing property. Based on the data from X-ray, sonic velocity, equilibrium regain rate, and accessibility, it is concluded that the degree of crystallinity, modulus, degree of orientation, density, equilibrium regain rate, and accessibility of blend filaments decreases with increasing chitin content in the blend filaments in the experiment scope. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The aim of this paper is the preparation and characterization of cellulose/chitin blend filaments over the experimental blend ratio scope i.e., 2.89 and 6.46% (w/w) chitin content through high wet modulus (HWM) procedure. The spinnability of the invested solutions was found to vary in the following order: chitin < cellulose < 9.5:0.5 blend < 9:1 blend < 8:2 blend < 5:5 blend (9:1 means the mass ratio of cellulose to chitin, so does 9.5:0.5, 8:2, and 5:5). The cross-section of the blend filaments is of chrysanthemum shape. It was shown through the SEM photographs that there existed grooves on the surface of filaments, which became coarse with increase in chitin content. Based on the data from X-ray, sonic velocity, intensity, and hygroscopicity, it is concluded that the degree of crystallinity, dry and wet intensity modulus, degree of orientation, and regain rate of the filaments decreased with increase in chitin content in the experiment scope. The mechanical properties of the blend filaments are much higher than those of Crabyon fiber and normal viscose filaments, which proves that the HWM method is an efficient way of preparing cellulose/chitin blend filaments with satisfactory mechanical properties and processing property. The blend filaments prepared have an effective biostatic effect on Staphylococcus aureus, Escherchia coil, and Corinebaterium michiganence according to different testing standards. Copyright (C) 2009 John Wiley & Sons, Ltd.

The focus of this article is the rheological properties of cellulose xanthate, chitin xanthate, and their blend solutions with cellulose/chitin blend weight ratios of 9.5 : 0.5, 9 : 1, 8 : 2, and 5 : 5 (mostly 9 : 1 blend solutions). The preparation and properties of fibers from 9 : 1 blend solutions and cellulose xanthate solutions are also discussed. The non-Newtonian index of the investigated solutions was found to vary in the following order: chitin cellulose > 9.5 : 0.5 blend > 9 : 1 blend > 8 : 2 blend > 5 : 5 blend. For 5–9 wt % 9 : 1 blend solutions, increasing the solution temperature aids the improvement of the fluidity of 9 : 1 blend solutions in the temperature range of 10–40°C. The zero shear viscosity decreases in an index manner with the solution temperature increasing. The 7–8 wt % 9 : 1 blend solutions have good filtering and rheological properties and are ideal for spinning fibers. The mechanical properties of blend fibers spun from 7% 9 : 1 blend solutions are lower than those of pure cellulose and are much higher than those of Crabyon fiber, and they still reach the national criteria and fit the need for further processing. This proves that the viscose method which we have developed here is an efficient way of preparing cellulose/chitin blend fibers with satisfactory mechanical properties and processing properties. Scanning electron microscopy photographs show that the surface of 9 : 1 blend fibers is coarser than that of pure cellulose fibers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

In this research, keratin was extracted from the disposable chicken feather using l-cysteine as reducing agent. Then, it was re-dissolved in the sodium carbonate-sodium bicarbonate buffer, and the pure keratin membrane and fiber were fabricated by doctor-blade casting process and wet spinning method, respectively. Scanning electron microscopy (SEM), fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were used to characterize the chemical and physical properties of resulting powder, membrane and fiber. Compared with the raw chicken feather, the regenerated keratin materials retain its chemical structure and thermal stability, their relative crystallinity is a little different depend on the shaping method, which leads to the difference in moisture regain. The mechanical results show that tensile strength of the keratin membrane researches 3.5MPa, have potential application in biomedical fields. However, the keratin fiber presents low tenacity, i.e. 0.5cN/dtex, this problem should be solved in order to apply the new fiber in textile and material science.

In this paper, rod-like chitin whisker was used as a filler to reinforce the chitosan membrane, and a series of composite membranes were prepared by casting-evaporation method. Mechanical testing shows that tensile strength of the resulting composite membrane with 3 wt% chitin whisker content reaches up to 110.3 MPa, which is about 2.8 times than that of neat chitosan membrane (38.5 MPa), and moisture regain of all composite membranes presents a decreasing tendency with increasing content of chitin whisker. Furthermore, SEM was used to investigate the morphology difference between neat chitosan membrane and composite membranes, to understand the reinforce mechanism of chitin whisker. Wide angle x-ray diffraction and Fourier transform infrared spectroscopy were used to visualize the structure change before and after the compositing processes. Besides, the bacterostatic test shows that this composite membrane presents effective inhibitory effect on Staphylococcus aureus, Escherchia coli and Corinebaterium michiganence respectively, which indicates it a promising material for packaging and wound dressing.

In this study, glycine hydrochloride (Gly·HCl) is confirmed to be a promising solvent for dissolving native chitosan and preparing regenerated chitosan membrane. As compared with the chitosan membrane prepared from traditional acetic acid, the membrane prepared from Gly·HCl by dry technique shows excellent tensile strength and initial modulus, i.e. 103.8MPa and 3.2GPa, respectively, which is superior to any chitosan membrane and most chitosan blend membranes reported in literatures. Besides, scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXD) and Fourier transform infrared spectroscopy (FT-IR) were used to visualize the difference between the two kind of regenerated chitosan membranes. The SEM results show that the membrane prepared from Gly·HCl by dry technique presents a novel structure, which ensures its high tenacity. Furthermore, the chitosan microporous membranes were also prepared using PEG as porogen.