Renewable resource modified polyol derived aliphatic hyperbranched polyurethane as a biodegradable and UV‐resistant smart material

Renewable resource tailored tough, elastomeric, biodegradable, smart aliphatic hyperbranched polyurethanes were synthesized using castor oil modified polyol containing fatty amide triol, glycerol, diethanolamine and monoglyceride of sunflower oil via an A_x + B_y (x , y ≥ 2) approach. To the best of our knowledge, this is the first report of the synthesis of solely aliphatic hyperbranched polyurethanes by employing renewable resources. The synthesized polyurethanes were characterized by Fourier transform infrared, NMR and XRD techniques. The hyperbranched polyurethanes exhibited good mechanical properties, especially elongation at break (668%), toughness (32.16 MJ m^?3) and impact resistance (19.02 kJ m^?1); also high thermal stability (above 300 °C) and good chemical resistance. Also, the hyperbranched polyurethanes were found to show adequate biodegradability and significant UV light resistance. Moreover, they demonstrated excellent multi‐stimuli‐driven shape recovery ability (up to 97%) under direct sunlight (10⁵ lux), thermal energy (50 °C) and microwave irradiation (450 W). The performance of the hyperbranched polyurethanes was compared with renewable resource based and synthetic linear polyurethane to judge the superiority of the hyperbranched architecture. Therefore, these new aliphatic macromolecules hold significant promise as smart materials for advanced applications. © 2017 Society of Chemical Industry     

ForceSpinning of polyacrylonitrile for mass production of lithium‐ion battery separators

We present results on the Forcespinning^® (FS) of Polyacrylonitrile (PAN) for mass production of polymer nanofiber membranes as separators for Lithium‐ion batteries (LIBs). Our results presented here show that uniform, highly fibrous mats from PAN produced using Forcespinning^®, exhibit improved electrochemical properties such as electrolyte uptake, low interfacial resistance, high oxidation limit, high ionic conductivity, and good cycling performance when used in lithium ion batteries compared to commercial PP separator materials. This article introduces ForceSpinning^®, a cost effective technique capable of mass producing high quality fibrous mats, which is completely different technology than the commonly used in‐house centrifugal method. This Forcespinning^® technology is thus the beginning of the nano/micro fiber revolution in large scale production for battery separator application. This is the first time to report results on the cycle performance of LIB‐based polymer nanofiber separators made by Forcespinning^® technology. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132, 42847.     

Caprolactam based block copolymers using polymeric activators

Caprolactam has been polymerised by sodium hydride in the presence of isocyanate terminated polymers. The latter participate in the initiation reaction and allow the preparation of materials where the prepolymer can amount to 50% of the product. There is evidence that block copolymers are formed, and the properties of polycaprolactam are considerably modified by the use of such activators. Styrene-butadiene or, particularly, caprolactone based isocyanates give materials having properties similar to the harder thermoplastic polyurethanes. The dependence of properties on the nature and amount of the polymeric activators, and the conditions of preparation and processing, have been investigated. Crystalline morphology has also been examined. Tensile strengths of 50 MN/m² with 550% elongation at break are readily attainable with these materials.     

N-甲基二乙醇胺嵌段聚氨酯材料的结构表征和性能研究

以N-甲基二乙醇胺为扩链剂合成了阳离子化及肝素化聚氨酯、重点对其结构进行了表征，分别使用离子型染料染色法、比色法、红外光谱法、元素分析法等方法系统分析了经过离子化以及肝素化处理后聚合物结构的变化，同时采用拉伸试验对其力学性能进行了测试，结果表明聚氨酯经离子化和肝素化处理后，强度有了相当大的提高；通过全血凝固时间实验证明肝素化聚氨酯具有较好的血液相容性，是一种理想的生物医用材料。     

The effect of diisocyanate isomer composition on properties and morphology of polyurethanes based on 4,4′-dicyclohexyl methane diisocyanate and mixed macrodiols (PDMS–PHMO)

Three series of polyurethanes were prepared having 42 wt % hard segments based on 4,4′-dicyclohexyl methane diisocyanate (H₁₂MDI) with trans,trans isomer contents in the 13 to 95 mol % range and 1,4-butanediol chain extender. The soft segments were based on macrodiols poly(hexamethylene oxide) (PHMO, MW 696), α,ω-bishydroxyethoxypropyl polydimethylsiloxane (PDMS, MW 940), and two mixed macrodiol compositions consisting of 80 and 20% (w/w) PDMS. H₁₂MDI with 35, 85, and 95% trans,trans isomer contents were obtained from commercial H₁₂MDI (13% trans, trans) by fractional crystallization, and all polyurethanes were prepared by a one-step bulk polymerization procedure. The polyurethanes based on the commercial diisocyanate-produced materials soluble in DMF with molecular weights in the 53,655–75,300 range and generally yielded clear and transparent materials. The polyurethanes based on H₁₂MDI with trans,trans contents of 35% or higher yielded materials insoluble in N,N-dimethylformamide (DMF) and were generally opaque. Mechanical properties, such as tensile strength and elongation at break, decreased with increasing trans,trans content, while the Young's modulus and Shore hardness increased. The polyurethanes based on mixed macrodiols yielded higher tensile properties than those of materials based on individual macrodiols. The best mechanical properties were observed for a polyurethane consisting of a soft segment based on PDMS–PHMO (80/20) and a hard segment based on commercial H₁₂MDI and BDO. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were employed to characterize the polyurethane morphology. DSC results confirmed that the polyurethanes based on H₁₂MDI with high trans,trans isomer were very highly phase separated, exhibiting characteristic hard segment melting endotherms as high as 255°C. The other materials were generally phase mixed. FTIR spectroscopy results corroborated DSC results. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 573–582, 1999     

Industrial applications and properties of short glass fiber-reinforced plastics

Short glass fibers for reinforcements of plastics have been commercially produced for over three decades. During this period, they have been used in virtually every polymer, as well as in other matrices, such as concrete and plaster. Their tensile strength/cost performance is still three times that of Kevlar® and more than 30 times better than carbon fibers. Similarly, excellent modulus/cost performance and high temperature/cost performance can be achieved. This article gives a review of short-fiber composites: their properties and use. Included is a comparison of compounding vs. in-house blending, fiber/flake hybrids, and reinforced polymer blends. Finally, several new materials still in development stages will be examined.     

A novel water-based epoxy coating using self-doped polyaniline–clay synthesized under supercritical CO2 condition for the protection of carbon steel against corrosion

The synthesis of a polyaniline–clay nanocomposite (PAniC NC) was achieved using the in situ polymerization of aniline in a Cloisite^® 30B nanoclay suspension in a supercritical CO₂ (Sc-CO₂) medium. The interfacial co-polymerization of aniline (ANI) and m-aminobenzenesulfonic acid (SAN) in the presence of Cloisite^® 30B was performed in Sc-CO₂/water to produce the SPANI-clay NC. The NC was then mixed with a water-based hardener. This water-based composite is developed with the goal of reducing environmental and health risks. The use of this Sc-CO₂ technique produced a composite material that resulted in the enhanced protection of carbon steel against corrosion when compared to a similar composite synthesized under atmospheric conditions. The materials obtained were characterized using UV/visible spectroscopy, X-ray powder diffraction and scanning and transmission electron microscopy. The anti-corrosion performance and the adhesion properties of these coatings were evaluated using standardized tests. Electrochemical impedance spectroscopy was also used to determine the electrochemical properties of these anti-corrosion coatings. Better exfoliation and dispersion of the clay was achieved using the Sc-CO₂ medium resulting in superior performances in corrosion and electrochemical tests because of the higher level of intercalation.     

Molding of biomedical segmented polyurethane delamination events and stretching behavior

Segmented polyurethane devices for medical applications are generally processed by the solution-casting technique. The processing parameters in the molding and demolding stages strongly affect the physicochemical properties of the finished articles. Thus, the solution concentration, immersion cycle and drying temperature, type of mold (material and geometry), additives, and the drying time between the casting of successive layers define the surface and bulk properties of the manufactured articles. In this work, new commercially available medical-grade segmented polyurethanes were processed by two techniques to obtain multilayer films. Processing parameters were chosen to ensure the generation of a coating with the desired structural and surface characteristics. In the solution-casting technique, multiple dipping of the preshaped former into the polymer solution were used to obtain proper film thickness. Thin and uniform plaques were produced by the spin-casting technique. The two materials selected have different chemical compositions: one is an aromatic poly(ether urethane urea) (Biospan^TM) and the other an aromatic ether-free polyurethane (Chronoflex^TM). An analysis of the possibility of delamination events, considering the influence of surface-modifying additives and drying times, is presented. The freeze–fracture surface appearance is qualitatively described by SEM. In addition, tensile properties are determined and their influence on demolding and assembling procedures are also discussed. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2159–2167, 1998     

Thermally curable polyurethanes containing naphthoxazine groups in the main chain

A new methodology has been developed for the modification of polyurethanes with reactive naphthoxazine moieties in order to expand their industrial applicability as electrical insulators. Thermoplastic and organosoluble poly(urethane‐co‐naphthoxazine)s were prepared by the reaction of NCO‐terminated urethane prepolymers made from various soft segments with a naphthoxazine‐containing diol chain extender. The prepared polymers were easily processed into thin films using either solution casting or compression moulding techniques. Heat treatment of these films under optimized conditions (200 °C for 30 min) led to the thermally activated ring‐opening polymerization of naphthoxazine moieties, and consequently crosslinked networks were obtained. All of the starting materials and the final polymeric compounds were fully characterized using spectroscopic methods and their physical and chemical properties evaluated and then correlated with their chemical structures. Due to their good elongation property (up to 70% elongation at break) in comparison to polynaphthoxazines, significant enhancement in decomposition temperature as well as high value of dielectric breakdown strength (up to 30 kV mm^?1) in comparison to polyurethanes, these materials are potentially applicable as electrical insulators with service temperatures higher than those for related unmodified polyurethanes. Copyright © 2010 Society of Chemical Industry     

Comparative studies of ultra high molecular weight polyethylene fiber reinforced composites

Ultra high molecular weight polyethylene fiber is a very promising material for making light-weight high strength and high impact resistant composites, especially for ballistic protective shields. Three commercially available materials designed specifically for ballistic applications are Spectra® woven cloth, Dyneema Fraglight® nonwoven felt, and Spectra Shield® Plus PCR prepreg were chosen for parallel comparisons. The high-temperature high-pressure sintering process was applied to all three materials. The physical, thermomechanical, and microstructural properties of the consolidated products were studied and compared, including their crystallinity, molecular orientation, impact resistance, interlaminar adhesion, flexural properties, and thermoformability. The differences in these materials and their structures are reflected in the different properties of the final products. The influence of different processing conditions on the properties also differs for each material. It is concluded that matrix free Spectra cloth composite has dominant advantages over the other two materials. POLYM. ENG. SCI., 47:1544–1553, 2007. © 2007 Society of Plastics Engineers     

Adhesives,syntactics and laminating resins for aerospace repair and maintenance applications from Ciba Specialty Chemicals

Ciba Specialty Chemicals, Performance Polymers Division, has been a leading supplier of materials to the aerospace industry for the fabrication, repair and assembly of interior and exterior aircraft components for many year. Araldite^®, Epibond^® and Epocast^® epoxy adhesives, syntactics and laminating resins in addition to Uralane^®, polyurethane adhesives have long been associated with quality, reliability and innovative chemistry. The majority of these systems are qualified to aircraft manufacturer’s specifications and are included as approved repair materials in structural repair manuals and serivce bulletins. Many of the adhesives, syntactics and laminating resins are self-extinguishing and exhibit the low flame, smoke and toxicity (FST) characteristics required to comply with industry legislation such as FAR (Federal Aviation Regulation) 25.853 which governs the requirements for materials used in aircraft interior applications. The aim of this paper is to review a number of newly developed Ciba materials for repair and maintenance with a specific emphasis on technical performance and novel methods of application which can increase cost effectiveness and reduce labour when compared to conventional methods.     

Lignin‐xylaric acid‐polyurethane‐based polymer network systems: Preparation and characterization

Polyurethanes (PU) were synthesized from lignin by first preparing a prepolymer from esterified sugar‐based trihydroxyl compound xylaric acid and a 20 mol % excess of methylene diphenyl diisocyanate. The prepolymer was crosslinked with 5, 10, and 15 wt % of an industrial soda lignin, and polyethylene glycol was used to bring soft segments into the material structure. The total amount of bio‐based starting materials was as high as 35%. Evidence for the reaction between the prepolymer and lignin was observed using Fourier transform infrared spectroscopic analysis and ¹³C nuclear magnetic resonance spectroscopy. The thermal properties of the materials were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The mechanical and viscoelastic properties of the materials were determined by dynamic mechanical analysis (DMA). The glass transition temperatures (T_g) obtained from DSC and DMA showed a trend of increasing T_g with the increasing amount of lignin. A similar trend was observed with TGA for the increasing thermal stability up to 550^oC with the increasing amount of lignin. The lignin‐polyurethanes obtained were stiff materials showing high Young's modulus values. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39714.     

Electrostrictive effect in polyurethanes

Polyurethane electrostriction was investigated by measuring the tensile electromechanical coupling coefficients of structurally different materials. True values of the strain coefficients M₃₃₁₁, M₃₃₂₂, and M₃₃₃₃ were obtained for four types of polymer: one commercial polyurethane (DOW 2103‐80 AE) and three polyurethanes synthesized at the Naval Surface Warfare Center, including two phase‐separated (PS) materials with molecular weights of 1000 and 2000 and one phase‐mixed (PM) material with a molecular weight of 2000. Measurements were performed at 2 kHz under a bias field of 4 MV/m at room temperature. Measured values of M₃₃₃₃ ranged from ?9.4 × 10^?18 to ?74.6 × 10^?18 m²/V², with the PM material exhibiting the largest coefficient. The electrostatic interaction (Maxwell stress) did not account for more than 15% of the total electromechanical activity in any of the materials. Furthermore, at the macroscopic level, an empirical relationship was established to predict the values of the electrostrictive coefficients from the dielectric constants and the compliance coefficients of the material. Finally, results indicated that, at the microscopic level, the phenomenon of electrostriction in polyurethanes could be best explained by the presence of charges inside the material (space–charge theory). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 399–404, 2003     

Synthesis of Functionalized High‐Oleic Soybean Oil Wax Coatings and Emulsions for Postharvest Treatment of Fresh Citrus Fruit

High‐oleic soybean oil is chemically functionalized in order to mimic the structure and physical properties of hydrogenated castor oil (HCO). The resulting wax‐like material is evaluated for use as an alternative to other commercial wax coatings for the postharvest treatment of fresh citrus fruit. The racemic nature of the material inhibits ordered crystalline arrangement and negatively affects its relative crystallinity (17.7%), hardness (0.59 ± 0.04 mm^?1), and melting profile (44–46 °C), with respect to HCO oil (37.7%, 5.33 ± 0.01 mm^?1, 83–87 °C). Nevertheless, compounding the new material with carnauba wax (CAR) imparts a very attractive gloss and prevents moisture loss significantly better than polyethylene, shellac, and CAR‐based coatings. Compounding the hydroxy‐functionalized high‐oleic soybean wax may potentially reduce dependence on imported CAR and other ingredients used in citrus coating emulsion formulations. Practical Applications: The soybean oil‐derived material described in this contribution provides two key performance characteristics desired by citrus growers and packing houses: an efficient barrier to moisture loss and an attractive shine. The synthesis of the hydroxy‐wax is facile and mild, and the materials can be readily formulated into emulsions as required for fruit coating applications. Use of the formulated coating can be extended to other agricultural commodities such as avocados, melons, and stone fruit.     

Fabrication and application of Diachem® electrodes

Conductive diamond coated electrodes have undergone intensive investigation over the past number of years. The unique electrochemical properties of diamond electrodes such as their extreme chemical resistance, even at high doping concentrations, and high overvoltage for water electrolysis opens the door to numerous applications. For the industrial use of extremely promising electrode material sufficient availability, also for large area electrodes is necessary. The development of large area DIACHEM^® electrodes therefore has been performed on a range of base materials of numerous material geometries. For the production of these electrodes a large area HFCVD process is used which allows for reproducible coatings of substrates up to 50×100 cm. A doping with boron allows the reproducible setting of the resistivity of the diamond coating in the range of 5 to 100 m Ω cm. The extent to which DIACHEM^® electrodes have been developed by now means that they can presently be applied in various industrial applications. The most important applications include: industrial waste water treatment, in particular the mineralization of toxic organic compounds; the disinfection of water; circulation systems with water which are only possible through use of an electrochemical recycling process; electrochemical synthesis, in particular from strong oxidising solutions and galvanic processes such as the recycling of chrome baths. Previous investigations have shown that the use of DIACHEM^® electrodes results in either a significant improvement in the effectiveness or that the process was only possible through use of this particular electrode material. The user gains a combination of the typical advantages of the electrochemical process with the high efficiency of the DIACHEM^® electrode which, in turn, has generated enormous interest in this particular material. In order to satisfy this interest, CONDIAS GmbH offers the DIACHEM^® electrode commercially.     

High elongation thermoplastic Polyester‐urethanes based on widely available diacid intermediates

A series of new α,ω‐dihydroxy terminated polyester oligomers are synthesized from the condensation reaction of various aliphatic diols with a mixture of diacids rich in 2‐methylglutaric acid, MGA, an abundant and well‐defined industrial product. Their adipic acid (AA)‐based counterparts are also prepared and the physico‐chemical properties of both types of polyols are thoroughly characterized. All these polyester polyols are then used to prepare segmented polyurethanes following a two‐stage process, by reacting them successively with 4,4′‐diphenylmethane diisocyanate, and 1,4‐butanediol. The resulting materials are then evaluated with respect to their thermal and dynamic or static mechanical properties. The observed characteristics and behaviors are quite similar between AA‐ or MGA‐based polyurethanes, except for the tendency of AA‐based samples to display partially crystallized soft domains. Such a phenomenon is prevented in MGA‐based samples because of the methyl side group, resulting in remarkably higher ultimate elongations for the new thermoplastic polyurethanes derived from MGA. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43410.     

Properties of polyisobutylene-polyurethane block copolymers: I. Macroglycols from ozonolysis of isobutylene-isoprene copolymer

The properties of a series of polyisobutylene (PIB) based polyurethanes were studied and compared to those reported in the literature for polyether, polyester, and polybutadiene-based polyurethanes. Good phase separation was reflected in the invariance of the soft segment T_n with increasing hard segment content. Increasing hard segment content resulted in larger domains, higher modulus and lower ultimate elongation. The modulus above the soft segment T_n was higher than that previously reported for polyurethanes of similar hard segment contant; improved phase separation and short contour lengths of the PIB chains were cited as possible causes of this behavior. Stress-strain data indicated a change from isolated to interconnected domain morphology with incerasing hard segment contant. Generally similar trends were seen for all types of urethanes. The overall properties of polybutadiene polyurethanes were closest to those of the polyisobutylene polyurethanes studied. The properties of both of these systems were suggested to suffer from significant synthesis problems in urethane formation due to the incompatibility of the nonpolar hydrocarbon soft segment and the polar diol chain extender. Preliminary environmental tests indicated that polyisobutylene based materials exhibit improved hydrolytic stability and reduced moisture permeability compared to polyether and polyester polyurethanes and greater oxidative stability compared to polybutadiene based materials.     

Effects of metallic coating on the combustion toxicity of engineering plastics

Experiments were conducted on 34 plastic materials having a variety of metallic coatings to determine the toxicity of their thermal decomposition products. Mice were exposed for 30 min in a dome exposure chamber to the products obtained by ramp-heating the samples from 200°C to 800°C. An LC₅₀ value was obtained for each material. Postmortem examinations were conducted on all dead mice, and on survivors after 14 days, to determine the gross pathological effects of exposure; particular attention was devoted to pulmonary pathology. The exposure protocol chosen has been extensively criticized, but it is very useful to study the effects of stress on mice, which was the most important part of this work. Experiments were made involving unrestrained mice in groups of four, restrained mice in groups of four and unrestrained single mice. The LC₅₀ values for single unrestrained mice were greater, by factors of 2–3, than those for four restrained mice, with the differences being shown to be statistically significant. This suggests that stress on the test animals will tend to reduce the LC₅₀ values in bench-scale smoke toxicity tests. The LC₅₀ values for all of the materials tested were equal to or higher than the value of 8 mg1^?1 representative of the contribution of carbon monoxide to post-flashover fires. Moreover, no ‘supertoxicants’ were found in the smoke of any of the materials tested. Finally, the coatings did not adversely affect the smoke toxicity of the substrate materials by a factor higher than 2–3 in any of the cases investigated. Uncoated polyethylene was the most toxic substrate material tested (LC₅₀ = 16 mgl^?1) and uncoated NORYL® resin was the least toxic (LC₅₀ = 91mgl^?1). Metallic coatings involving Cu, Ni, graphite, and Zn typically had no statistically significant effect on the smoke toxicity of the substrate materials, although Ni coatings increased the smoke toxicity of ABS I and of white polycarbonate structural foam, by factors of 2–3. Overall smoke toxicities were well correlated with production of carbon monoxide (r=0.84) and carbon dioxide (r=0.82); oxygen levels and chamber temperature did not vary beyond acceptable limits. The materials tested generating the more toxic smokes (including polyethlene, polystyrene, and several polycarbonates) produced severe lung damage at low concentrations. The LC₅₀ of these materials was also typically greater than predicted on the basis of CO production. Other materials (including several coating on NORYL® resin and Lexan® polycarbonate) produced pulmonary damage at higher concentrations amd had LC₅₀ values more closely correlated with CO production. None of the polyurethane materials tested produced severe lung damage at the concentrations employed.     

Flexible‐elastic copolymerized polyurethane‐tannin foams

Open cell foams obtained by the simultaneous coreaction of condensed flavonoid tannins with an alkoxylated fatty amine and polymeric diphenylmethane isocyanate yielded highly flexible/elastic polyurethane foams. Copolymerized amine/isocyanate/tannin oligomers were identified by ¹³C NMR and MALDI‐TOF spectroscopy. In general, between 30% and 50% of natural tannins is added to the components used to obtain polymerisation of the polyurethane. The characteristic of these new, partially biosourced polyurethanes is that the tannin present slows down burning, some of them can be made flame self‐extinguishing and if burning they neither flow nor asperge flaming material around, contrary to what occurs with normal polyurethanes. This limits the possibility of transmitting fire to other materials in the same environment. Cyclic compression tests were carried out showing that after 50 cycles foam recovery was in excess of 80%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40499.     

Influence of iron doping towards the physicochemical and biological characteristics of hydroxyapatite

Hydroxyapatite (HAP) is the naturally occurring mineral form of calcium apatite and the most studied material as a bone substituent. Considering HAP's inherent properties, this study explored changes in HAP's characteristics from doping with other metals such as Fe. To form pure HAP and Fe-HAP with different amounts of Fe, we used the hydrothermal approach, and the composites that formed were thoroughly analyzed for their crystallinity, surface bonding, morphology, magnetic behavior, mechanical strength, biocompatibility, hemocompatibility, and in vitro cytotoxicity. The powder XRD studies confirmed the samples' crystallinity, and the lowest crystalline size was 19.7 nm in 10Fe-HAP. The FTIR analysis confirmed the formation of HAP by the hydroxyl, phosphate, and carbonate groups. The FESEM demonstrated that the morphology of the pure HAP was rod-shaped, which transformed into spheres after Fe doping. The EDS analysis confirmed the successful formation of HAP and Fe-HAP composites. The magnetic studies indicated the diamagnetic behavior of the pure HAP, while the Fe-doped HAPs had a superparamagnetic nature with saturation magnetizations (M_s) of 2Fe-HAP, 4Fe-HAP, and 10Fe-HAP at 0.0062, 0.0092, and 0.029 emu/g respectively. Assessment of the mechanical properties, biocompatibility, hemocompatibility, and cytotoxicity indicated that the Fe-doped HAPs were superior to the pure HAP, and among the Fe-HAPs, the 10Fe-HAP) had the highest amount of Fe and the best characteristics. The studies also indicated that Ca²⁺ interactions influenced the cells via HAP doping with that of Fe, equally increasing the physicochemical and biological properties.