Tensile properties of natural fabric Hildegardia populifolia/polycarbonate toughened epoxy composites

The environmentally friendly composites of natural fabric Hildegardia populifolia/polycarbonate toughened epoxy were prepared. The effect of fabric content and the orientation of the fibers in the fabric on the tensile properties of the composites was studied. The effect of alkali treatment of the fabric and a silane coupling agent on the tensile properties was also studied. The tensile properties improved with alkali treated fabric content when a coupling agent was used. Polym. Compos. 25:563–568, 2004. © 2004 Society of Plastics Engineers.     

Effect of alkali treatment on the flexural properties of Hildegardia fabric composites

A uniaxial natural fabric of Hildegardia populifolia was treated with 5% sodium hydroxide solution for 1 h, and the resulting changes were analyzed by polarized and scanning electron microscopic techniques. The untreated and treated H. populifolia fabric was reinforced in epoxy and toughened with 10% polycarbonate. The variation of the flexural strength and flexural modulus with different fabric contents and fiber orienrations was studied. The effect of sodium hydroxide and a silane coupling agent on the flexural properties of the composite was also studied. It was observed that the flexural properties increased on alkali treatment and when the coupling agent was used. The morphology of the cryogenically fractured surfaces indicated good bonding between the matrix and the reinforcement when a coupling agent was used. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1297–1302, 2006     

Chemical resistance,void contents,and morphological properties of Hildegardia fabric/polycarbonate‐toughened epoxy composites

A uniaxial natural fabric of Hildegardia populifolia was used as a reinforcement for a polycarbonate‐toughened epoxy. The Hildegardia fabric was treated with a 5% sodium hydroxide solution for 1 h. The fabric was spray‐coated with a 1% silane‐based coupling agent. The variation of the chemical resistance and void content with different fabric contents and fiber orientations was studied. The morphology of the fractured composites was investigated with scanning electron microscopy (SEM). SEM micrographs indicate that the bonding between the Hildegardia fabric and the matrix was enhanced partially by the alkali treatment. The alkali treatment in the presence of the silane coupling agent gave rise to matrix skin formation on the surface of the fibers, which indicated good bonding between the reinforcement and the matrix. Hildegardia/polycarbonate‐toughened epoxy composites were found to have reasonable chemical and water resistance. The liquid absorption increased when the fabric was treated with an alkali, when the coupling agent was used, and in the presence of water and aqueous solutions. The void content of the composites decreased with increasing fabric content. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Mechanical properties and biodegradability of crosslinked soy protein isolate/waterborne polyurethane composites

With anionic waterborne polyurethane (WPU) as a plasticizer and ethylene glycol diglycidyl ether (EGDE) as a crosslinker, we successfully prepared crosslinked soy protein isolate (SPI) plastics. Anionic WPU was mixed with SPI and EGDE in an aqueous dispersion at room temperature. The mixed aqueous dispersion was cast and cured, and the obtained material was pickled and hot‐pressed to produce the crosslinked SPI/WPU sheets. The resulting sheets containing about 60 wt % SPI were characterized with infrared spectroscopy, scanning electron microscopy, atomic force microscopy, dynamic mechanical analysis, and tensile testing, and biodegradation testing of the sheets was performed in a mineral salt medium containing microorganisms. The results revealed that the crosslinked SPI/WPU plastics with EGDE concentrations of 2–4 wt % possessed high miscibility, good mechanical properties, and water resistivity. In addition, the crosslinked sheets could be biodegraded, and the half‐life of the biodegradation for a sheet crosslinked with 3 wt % EGDE was calculated to be less than 1 month. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 465–473, 2005     

Green composites and blends from leather industry waste

Blends based on protein hydrolysate (PH), derived from waste products of the leather industry, and poly(ethylene‐co‐vinyl acetate) (EVA), were obtained by reactive blending and their physico‐chemical properties as well as their mechanical and rheological behavior were evaluated. The effect of vinyl acetate content and of a transesterification agent added to increase interaction between polymer and bio‐based components were investigated. Novel biodegradable polymeric materials for spray mulching coatings were also obtained from hydrolyzed proteins and end‐functionalized poly(ethylene glycol) (PEG), which was used as crosslinking agent. These products, almost entirely obtained from renewable sources, represent a new type of biodegradable material which looks promising for several applications, for instance in packaging or in agriculture as transplanting or mulching films with additional fertilizing action of PH. POLYM. COMPOS., 37:3416–3422, 2016. © 2015 Society of Plastics Engineers     

Soy protein isolate/kraft lignin composites compatibilized with methylene diphenyl diisocyanate

Methylene diphenyl diisocyanate (MDI) was used to compatibilize kraft lignin (KL)/soy protein isolate (SPI) blends. The structure and properties of the resultant composite materials were investigated with wide‐angle X‐ray diffraction, differential scanning calorimetry, dynamical mechanical thermal analysis, scanning electron microscopy, and tensile and water absorption tests. The results indicated that graft copolymerization and a moderate degree of crosslinking between KL and SPI occurred in the composites because of the compatibilization of MDI, which favored the strengthening of the materials. Interestingly, the addition of 2 parts of MDI caused a simultaneous enhancement of the modulus, strength, and elongation of KL/SPI blends. The structure with grafting and moderate crosslinks reduced the water absorption of the materials. However, the excess crosslinks hindered the interaction between KL and SPI, resulting in a reduction of the mechanical properties. Scanning electron microscopy showed that the domains of the graft copolymer and crosslinking enrichment existed in the blends. When the MDI content was relatively low, these domains became concentric points of stress, enhancing the mechanical properties. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 624–629, 2004     

Green composites based on wheat gluten matrix and posidonia oceanica waste fibers as reinforcements

In this work, green composites from renewable resources were manufactured and characterized. A fibrous material derived from Posidonia oceanica wastes with high cellulose content (close to 90 wt% of the total organic component) was used as reinforcing material. The polymeric matrix to bind the fibers was a protein (wheat gluten) type material. Composites were made by hot‐press molding by varying the gluten content on composites in the 10–40 wt% range. Mechanical properties were evaluated by standardized flexural tests. Thermo‐mechanical behavior of composites was evaluated with dynamic mechanical analysis (torsion DMA) and determination of heat deflection temperature. Morphology of samples was studied by scanning electronic microscopy and the water uptake in terms of the water submerged time was evaluated to determine the maximum water uptake of the fibers in the composites. Composites with 10–40 wt% gluten show interesting mechanical performance, similar or even higher to many commodity and technical plastics, such as polypropylene. Water resistance of these composites increases with the amount of gluten. Therefore, the sensitiveness to the water of the composites can be tailored with the amount of gluten in their formulation. POLYM. COMPOS., 34:1663–1669, 2013. © 2013 Society of Plastics Engineers     

Biologically degradable fiber-reinforced urethane composites from wheat straw

Urethane type adhesive mixtures containing poly(MDI) were used to prepare biodegradable urethane type composites containing wheat stalks. According to the mechanical properties, i.e., tensile strength, bending strength, and hardness of the composites, the ratio of wheat stalks to sticking mixtures, the technological pressure used, and the size of the wheat stalks were optimized. The mechanism of the possible chemical reaction is also discussed.     

Hybrid fiber fabric composites from poly ether ether ketone and glass fiber

Poly ether ether ketone (PEEK) polymer was extruded into filaments and cowoven into unidirectional hybrid fabric with glass as reinforcement fiber. The hybrid fabrics were then converted into laminates and their properties with special reference to crystallization behavior has been studied. The composite laminates have been evaluated for mechanical properties, such as tensile strength, interlaminar shear strength (ILSS), and flexural strength. The thermal behavior of the composite laminates were analyzed using differential scanning calorimeter, thermogravimetric analyzer, dynamic mechanical analyzer (DMA), and thermomechanical analyzer (TMA). The exposure of the fabricated composite laminates to high temperature (400 and 500°C) using radiant heat source resulted in an improvement in the crystallanity. The morphological behavior and PEEK resin distribution in the composite laminates were confirmed using scanning electron microscope (SEM) and nondestructive testing (NDT). Although DMA results showed a loss in modulus above glass transition temperature (T_g), a fair retention in properties was noticed up to 300°C. The ability of the composite laminates to undergo positive thermal expansion as confirmed through TMA suggests the potential application of glass–PEEK composites in aerospace sector. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117:1446–1459, 2010     

绿色天然化妆品

虽然受经济衰退的束缚,天然个人护理品的购买力依然从2011年开始复苏。介绍了最新的各种天然护理品品牌以及含天然组分的新品。     

Fabrication and characterization of eggshell powder particles fused wheat protein isolate green composite for packaging applications

Ample biodegradable eggshell powder (ESP)/wheat protein isolate (WPI) composite films were made by solution casting method of altering the WPI solution and fused with ESP particles in the percentage of 5, 10, 20, 30, and 40% (w/w) and asses the properties, i.e., physical, mechanical, and thermal as a function of ESP concentration. Determine the unification of ESP particles into the WPI matrix by X‐ray diffraction, fluorescence spectra, and SEM analysis. The data clearly showed the successful incorporation of ESP particles and good compatibility with the WPI and also mechanical properties and thermal stability of composite film increasing with the increasing ratio of ESP. Microstructural evaluation confirmed the aggregation and distribution of ESP particles within the WPI matrix and validated the results of functional properties of the WPI/ESP film. The results confirmed that the composite films have potential applications in the field of food and medicinal packaging especially for photosensitive medicines in a very simple and cheap way. POLYM. COMPOS., 37:3280–3287, 2016. © 2015 Society of Plastics Engineers     

Physical and mechanical characterization of jute fabric composites

As‐received and washed jute fabrics were used as reinforcement for a thermoset resin. The mild treatments performed on the jute fabrics did not significantly affect their physical and thermal behaviors. The washed fibers absorbed less water than the unmodified (as received) ones, indicating that the coating used to form the fabrics was hygroscopic. Measurements of the fiber mechanical properties showed a high dispersion due to fiber irregularities, although the values obtained were in agreement with data reported in the literature. These results were also analyzed with the Weibull method. To investigate the effect of the jute treatments on the interface properties, impact, compression, and tensile tests were carried out. The composites made from as‐received jute had the highest impact energy, which was probably associated with weak interfacial adhesion. Composite samples behaved more ductilely in compression than in tensile situations due to the brittle characteristics of the resin used as matrix. The effect of the orientation of the fibers with respect to the direction of the applied force in the different mechanical tests was also studied. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 639–650, 2005     

改性大豆分离蛋白对顺丁橡胶/丁苯橡胶复合材料性能的影响

将糊化改性的大豆分离蛋白( SPI)等量替代炭黑填充至顺丁橡胶/丁苯橡胶中,研究了改性SPI的粒径和热性能,考察了改性SPI用量对橡胶复合材料物理机械性能、热性能、压缩生热性能的影响,并与白炭黑和轻质碳酸钙填充复合材料进行了对比.结果表明,改性SPI的中位径由原来的115.25 μm减小至37.63 μm,比表面积由原...     

Surface modification of poly (ethylene terephthalate) fabric by soy protein isolate hydrogel for wound dressing application

In this study, a composite of poly (ethylene terephthalate) (PET) fabric and soy protein isolate (SPI) hydrogel loaded with gabapentin was developed. For covalent attachment of SPI on the surface of PET fabric, graft polymerization of acrylic acid (AA) on the surface of PET fabric was performed and then carboxyl groups available in the structure of AA were activated using EDAC and then SPI was coated on the surface of PET fabric. The results revealed appropriate connection between hydrogel and modified fabric. The hydrogel was characterized by swelling test and the drug release behavior was investigated. It was found that the casting temperature affects the swelling ratio of the hydrogel and an appropriate release profile of the drug was observed. The surface of fabric was characterized by contact angle measurement, electron microscopy, and infrared spectroscopy. In vitro cell culture study was performed using NIH 3T3 mouse fibroblasts to investigate the biocompatibility of final composite and MTS results along with morphology of cells on the surface of PET fabric coated with SPI revealed the biocompatibility of final product and no cell cytotoxicity was observed in modified PET fabric.     

Preparation of soy protein concentrate and isolate from extruded-expelled soybean meals

Soy protein concentrates (SPC) and soy protein isolates (SPI) were produced from hexane-defatted soy white flakes and from two extruded-expelled (EE) soy protein meals with different degrees of protein denaturation. Processing characteristics, such as yield and protein content, and the key protein functional properties of the products were investigated. Both acid-and alcohol-washed SPC from the two EE meals had higher yields but lower protein contents than that from white flakes. Generally, SPC from an acid wash had much better functional properties than those from an alcohol wash. The SPI yield was highly proportional to the protein dispersibility index (PDI) of the starting material, so the EE meal with lower PDI had lower SPI recovery. The protein content in SPI prepared from EE meals was about 80%, which was lower than from white flakes. Nevertheless, SPI from EE meals showed functional properties similar to or better than those from white flakes. The low protein contents in SPC and SPI made from EE meals were mainly due to the presence of residual oil in the final products. SPI made from EE meals had higher concentration of glycinin relative to β-conglycinin than that from white flakes.     

Thermoplastic polyurethane composites prepared from mechanochemically activated waste cotton fabric and reclaimed polyurethane foam

In this study, thermoplastic polyurethane (PU) composites were successfully prepared from waste cotton fabric (WCF) and reclaimed PU foam derived from the shoe manufacturing industry through melt mixing. A pan‐mill‐type mechanochemical reactor made in our laboratory was applied to determine the mechanochemical activation of WCF. The intramolecular and intermolecular hydrogen bonds of WCF could be broken up through pan milling because of the fairly strong shearing and squeezing forces. Moreover, the simultaneous reduction of particle size and the large increment of the specific surface area of pan‐milled WCF benefitted its dispersion and the interfacial adhesion with the PU matrix. Mechanochemically activated WCF could be used as a low cost but effective functional additive to enhance the melt processability and mechanical properties of PU/WCF composites. With the addition of 75‐phr WCF, the heat shrinkage of the melt‐reprocessed PU decreased sharply from its original 11.4 to 0.3%. Meanwhile, the tensile strength of the composites was enhanced from 10.3 to 23.2 MPa. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

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.     

Sintering behavior of fluorapatite-based composites produced from natural phosphate and alumina

In this investigation, we studied the reaction-sintering between fluorapatite and alumina using natural phosphate and boehmite. The addition of alumina, resulting from the boehmite transitions, to the fluorapatite (FAp) has been carried out to obtain various composites based on FAp, yeelemite, mayenite, grossite (CA₂), hibonite (CA₆) and β-TCP. Several samples were prepared by varying the boehmite (AlOOH) amount to obtain six compositions which contain after sintering: 5, 10, 15, 20, 25 and 30 wt% of Al₂O₃. After ball-milling for 5 h, all compositions were sintered in the air for 2 h at different temperatures ranging from 1000 to 1500 °C. The reactions and phase transformations between fluorapatite and boehmite were studied and characterized by DTA/TG, XRD, FT-IR, apparent density and open porosity measurements, micro-hardness and SEM analysis. The micro-hardness and densification of the sintered body showed a marked improvement by increasing the alumina content and sintering temperature. Especially, sample containing 25% alumina exhibited the highest densification at 1400 °C (2.95 g/cm³) and excellent micro-hardness of about 6.5 ± 0.25 GPa. So the preparation of low cost composites based on fluorapatite, yeelimite and grossite from natural phosphate and alumina are feasible.     

Properties of calcium phosphates ceramic composites derived from natural materials

In this study, ceramics containing mixed phases of hydroxyapatite/beta-tricalcium phosphate (HA/β-TCP) were fabricated by a solid-state reaction technique. The HA powder was synthesized from cockle shells while the β-TCP powder was synthesized from egg shells. Pure HA and β-TCP fine powders were successfully obtained. The HA and β-TCP were mixed and subjected to a thermal treatment up to 1100 °C. To form the mixed phase ceramics, the resulting powders were sintered at 1350 °C. Effects of HA concentration on the properties of the studied ceramic were investigated. X-ray diffraction analysis revealed that all samples presented multiphase of calcium phosphate compounds. Average grain size of the ceramics decreased with the HA additive content. The 75 wt% HA ceramic showed the maximum hardness value (5.5 GPa) which is high when compared with many calcium phosphate ceramics. In vitro bioactivity test indicated that apatite forming increased with the HA additive content. To increase antibacterial activity, selected ceramics were coated with AgNO₃. Antibacterial test suggested that an Ag compound coating on the ceramics could improve the antibacterial ability of the studied ceramics. In addition, the antibacterial ability for the Ag coated ceramics depended on the porosity of the ceramics.     

Structural degradation and mechanical fracture of hybrid fabric reinforced composites

This investigation involves the study of accelerated environmental aging in two polymer composite laminates reinforced by hybrid fabrics based on carbon, Kevlar and glass fibers. Composite laminate configurations are defined as a laminate reinforced with E‐glass fiber and Kevlar 49 fiber hybrid fabric (GK) and another laminate reinforced with E‐glass fiber and AS4 carbon fiber hybrid fabric (GC). Both laminates were impregnated with epoxy vinyl ester thermosetting resin (Derakane 470‐300) consisting of four layers. Morphological studies (photo‐oxidation process and structural degradation) of environmental aging were conducted, in addition to comparative studies of the mechanical properties and fracture characteristics under the action of uniaxial tensile and three‐point bending tests in specimens in the original and aged conditions. With respect to uniaxial tensile tests for both laminates, good mechanical performance and little final damage (small loss of properties) was caused by the aging effect. However, for the three‐point bending tests, for both laminates, the influence of aging was slightly higher for all parameters studied. The low structural deterioration in the laminates is attributed to the high performance with the heat of the matrix (Derakane 470‐300) and the characteristics of the hybrid fabric, exhibiting fiber/matrix interface quality. POLYM. ENG. SCI., 56:657–668, 2016. © 2016 Society of Plastics Engineers