Synthesis and Properties Modified Feather Keratin-Based Motor Oil Sorbing Cryogels with High Oil Holding Capacity

Oleic acid was used to modify keratin extracted from chicken feathers by free radical initiated graft copolymerization. Thereafter, the modified keratin was used for the synthesis of cryogels. The influence of oleic acid modification, the crosslinker content, and the protein concentration on the properties of the cryogels were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, SDS-PAGE, and through oil holding capacity tests. To enhance the sorption properties, the cryogels were crosslinked with glutaraldehyde. Varying protein concentration from 1.27 to 5.09 wt% and glutaraldehyde concentration from 0 to 5 wt% produced cryogels with oil holding capacity ranging from 4.56 to 10.76 g/g. The highest results exceeded the sorption capacity of previously published oleic acid modified woodchips (6.3 g/g) as well as polypropylene (6 g/g), which is the standard material used in industry.     

Dissolving Feather Keratin Using Sodium Sulfide for Bio-Polymer Applications

Feather keratin has been widely studied for use as a bio-based material. In this paper, we dissolve feather keratin using industrial sodium sulfide to investigate the yield, dissolved keratin characteristics, and properties of regenerated products to assess the potential of using sodium sulfide as a means of converting waste feathers into a bio-polymer. Optimal conditions appeared to require short incubation times in order to give maximum strength in the regenerated product. This limits the yield to approximately 55%. Air-dried films and acid-precipitated samples are all readily re-crosslinked, suggesting the re-crosslinking process is robust. Minimizing exposure to the highly alkaline conditions appears favorable to final product strength through minimizing alkaline chain damage. The β-sheet structure of the parent keratin is largely maintained. The regenerated keratin was shown to have potentially attractive physical properties for use as a bio-polymer.     

A Processing,Characterization and Marine Biodegradation Study of Melt-Extruded Polyhydroxyalkanoate (PHA) Films

A series of polyhydroxyalkanoates (PHA), all containing 1% nucleating agent but varying in structure, were melt-processed into films through single screw extrusion techniques. This series consisted of three polyhydroxybutyrate (PHB) and three polyhydroxybutyrate-valerate (PHBV) resins with varying valerate content. Processing parameters of temperature in the barrel (165–173 °C) and chill rolls (60 °C) were optimized to obtain cast films. The gel-permeation chromatography (GPC) results showed a loss of 8–19% of the polymer’s initial molecular weight due to extrusion processing. Modulated differential scanning calorimetry (MDSC) displayed glass transition temperatures of the films ranging from −4.6 to 6.7 °C depending on the amount of crystallinity in the film. DSC data were also used to calculate the percent crystallinity of each sample and slightly higher crystallinity was observed in the PHBV series of samples. X-ray diffraction patterns did not vary significantly for any of the samples and crystallinity was confirmed with X-ray data. Dynamic mechanical analysis (DMA) verified the glass transition trends for the films from DSC while loss modulus (E′) reported at 20 °C showed that the PHBV (3,950–3,600 MPa) had the higher E′ values than the PHB (3,500–2,698 MPa) samples. The Young’s modulus values of the PHB and PHBV samples ranged from 700 to 900 MPa and 900 to 1,500 MPa, respectively. Polarized light microscopy images revealed gel particles in the films processed through single-screw extrusion, which may have caused diminished Young’s modulus and tensile strength of these films. The PHBV film samples exhibited the greatest barrier properties to oxygen and water vapor when compared to the PHB film samples. The average oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) for the PHBV samples was 247 (cc-mil/m²-day) and 118 (g-mil/m²-day), respectively; while the average OTR and WVTR for the PHB samples was 350 (cc-mil/m²-day) and 178 (g-mil/m²-day), respectively. Biodegradation data of the films in the marine environment demonstrated that all PHA film samples achieved a minimum of 70% mineralization in 40 days when run in accordance with ASTM 6691. For static and dynamic incubation experiments in seawater, microbial action resulting in weight loss as a function of time showed all samples to be highly biodegradable and correlated with the ASTM 6691 biodegradation data.     

Biodegradation of keratin waste: Theory and practical aspects

Keratin-rich by-products, i.e. bristles, horns and hooves, chicken feathers and similar, are a source of nutrients for animals (amino acids) and plants (N, S). Contemporary developments in the management of keratin waste in feeds and fertilizers comply with human and animal health protection regulations and respect the principles of ecological development. Biotechnological methods employing keratinolytic bacteria and microscopic fungi play a key role in processing keratin waste.This study reviews the current knowledge on the ecology and physiology of keratinolytic microorganisms and presents the biodegradation mechanism of native keratin. The structure and chemical composition of keratin proteins are described, and methods of keratin waste biotransformation into products of practical industrial and natural value, especially composts, are discussed.     

Biodegradability of Poly (lactic acid), Preparation and Characterization of PLA/Gum Arabic Blends

In this study, the biodegradation of PLA films using microorganisms from Lake Bogoria (Kenya) were investigated. The biodegradation tests done using certain strains of thermophilic bacteria showed faster biodegradation rates and demonstrated temperature dependency. The biodegradation of the PLA films was studied using Gel Permeation Chromatography (GPC) and light microscopy. The biodegradation of PLA was demonstrated by decrease in molecular weight. The preparation and characterization of PLA/Gum Arabic blends were also investigated using DSC, TGA, TMA and NMR. In summary, the results obtained in this research show that PLA films undergo fast biodegradation using thermophiles isolated from Lake Bogoria. The PLA/GA blends studies show it is possible to prepare films of varying hydrophobic–hydrophilic properties for various applications.     

Feather Fiber Reinforced Light-Weight Composites with Good Acoustic Properties

Three to four billion pounds of chicken feathers are wasted in the United States annually. These feathers pose an environmental challenge. In order to find a commercial application of these otherwise wasted feathers, composites have been prepared from feathers. Flexural, impact resistance, and sound dampening properties of composites from chicken feather fiber (FF) and High Density Polyethylene/Polypropylene (HDPE/PP) fiber have been investigated and compared with pulverized chicken quill-HDPE/PP, and jute-HDPE/PP composites. Sound dampening by FF composites was 125% higher than jute and similar to quill although mechanical properties were inferior to the latter two. In ground form, FF and jute composite properties were similar except for 34% higher modulus of jute; under the same formulation and processing conditions, ground FF composites had nearly 50% lower mechanical properties compared with ground quill composites. It was found that voids and density of composites have effect on mechanical and sound dampening properties; however, no direct relationship was found between mechanical properties and sound dampening.     

Fabrication and Characterization of Biodegradable Composite Films Made of Using Poly(caprolactone) Reinforced with Chitosan

Chitosan was dissolved in 2?% aqueous acetic acid solution and the films were prepared by solution casting. Values of tensile strength (TS), tensile modulus (TM), elongation at break (Eb?%) and water vapor permeability (WVP) of the chitosan films were found to be 30?MPa, 450?MPa, 8?% and 4.7?g?mm/m²?day?kPa, respectively. Poly(caprolactone) (PCL) films were prepared from its granules by compression molding and the values of TS, TM, Eb and WVP were 14?MPa, 220?MPa, 70?% and 1.54?g?mm/m²?day?kPa, respectively. PCL was reinforced with chitosan films, and composite films were prepared by compression molding. Amount of chitosan in the composite films varied from 10 to 50?% (w/w). It was found that with the incorporation of chitosan films in PCL, both the values of TS and TM of composite films increased significantly. The highest mechanical properties were found at 50?% (w/w) of chitosan content. The Oxygen transmission rate (OTR) of composite film was found to decrease significantly than PCL films. Thermal properties of the composite were also improved as compared to PCL. The water uptake test of the composite also showed promising results with a good stability of composite films. The interface of the composite was investigated by scanning electron microscopy and showed good interfacial adhesion between PCL and chitosan films.     

Preparation and Characterization of Gamma Irradiated Sugar Containing Starch/Poly (Vinyl Alcohol)-Based Blend Films

Blends based on different ratios of starch (35–20%) and plasticizer (sugar; 0–15%) keeping the amount of poly(vinyl alcohol) (PVA) constant, were prepared in the form of thin films by casting solutions. The effects of gamma-irradiation on thermal, mechanical, and morphological properties were investigated. The studies of mechanical properties showed improved tensile strength (TS) (9.61 MPa) and elongation at break (EB) (409%) of the starch-PVA-sugar blend film containing 10% sugar. The mechanical testing of the irradiated film (irradiated at 200 Krad radiation dose) showed higher TS but lower EB than that of the non-radiated film. FTIR spectroscopy studies supported the molecular interactions among starch, PVA, and sugar in the blend films, that was improved by irradiation. Thermal properties of the film were also improved due to irradiation and confirmed by thermo-mechanical analysis (TMA), differential thermo-gravimetric analysis (DTG), differential thermal analysis (DTA), and thermo-gravimetric analysis (TGA). Surface of the films were examined by scanning electron microscope (SEM) image that supported the evidence of crosslinking obtained after gamma irradiation on the film. The water up-take and degradation test in soil of the film were also evaluated. In this study, sugar acted as a good plasticizing agent in starch/PVA blend films, which was significantly improved by gamma radiation and the prepared starch-PVA-sugar blend film could be used as biodegradable packaging materials.     

Biodegradable Composites Containing Chicken Feathers as Matrix and Jute Fibers as Reinforcement

This research demonstrates that chicken feathers can be used as matrix to develop completely biodegradable composites with properties similar to that of composites having polypropylene (PP) as matrix. Feathers are ubiquitous and inexpensive but have limited industrial applications. Feathers have been preferably used for composite applications due to their low density and presence of hollow structures that facilitate sound absorption. However, previous approaches on using feathers for composites have used the whole feather or the feather fractions as reinforcement with synthetic polymers as matrix resulting in partially degradable composites. In addition, the hydrophilicity of the feathers and hydrophobicity of the synthetic matrix results in poor compatibility and therefore less than optimum properties. Although it has been shown that feathers can be made thermoplastic and suitable to develop films and other thermoplastics, there are no reports on using feathers as matrix for composites. In this research, chicken feathers were used as matrix and jute fibers as reinforcement to develop completely biodegradable composites. Tensile, flexural and acoustic properties of the feather-jute composites were compared to PP-jute composites. Utilizing feathers as matrix could enable us to develop low cost 100 % biodegradable composites containing feathers or other biopolymers as the reinforcement.     

Structure and Properties of Chicken Feather Barbs as Natural Protein Fibers

The structure and properties of chicken feather barbs makes them unique fibers preferable for several applications. The presence of hollow honeycomb structures, their low density, high flexibility and possible structural interaction with other fibers when made into products such as textiles provides them unique properties unlike any other natural or synthetic fibers. No literature is available on the physical structure and tensile properties of chicken feather barbs. In this study, we report the physical and morphological structure and the properties of chicken feather barbs for potential use as natural protein fibers. The morphological structure of chicken feather barbs is similar to that of the rachis but the physical structure of the protein crystals in chicken feather barbs is different than that reported for feather rachis keratin. The tensile properties of barbs in terms of their strength and modulus are similar but the elongation is lower than that of wool. Using the cheap and abundant feathers as protein fibers will conserve the energy, benefit the environment and also make the fiber industry more sustainable     

Pyrolysis characteristics and kinetics of chicken litter

Chicken litter generally consists of a mixture of bedding, manure, feathers and spilled food. Flock of birds litter (flock) is a litter consisting of hardwood shavings, feed, feathers and manure; and broiler litter (broiler) is a cake of chicken litter. A kinetic investigation of the pyrolysis of chicken litter (flock and broiler) was carried out using thermogravimetric analysis (TGA) at heating rates of 5 degrees C/min, 10 degrees C/min and 20 degrees C/min. Most of the materials decomposed between 270 degrees C and 590 degrees C at each heating rate. The region of decomposition of flock and broiler was slightly lower than that of the wood chips. Wood chips (bedding material) decomposed in two stages, while flock and broiler decomposed in three stages. Apparent activation energies increased from 99 to 484 kJ/mol for the three samples when the pyrolytic conversion increased from 5% to 95%.     

Properties of Starch/PVA Blend Films Containing Citric Acid as Additive

Starch/polyvinyl alcohol (PVA) blend films were prepared successfully by using starch, polyvinyl alcohol (PVA), glycerol (GL) sorbitol (SO) and citric acid (CA) for the mixing process. The influence of mixing time, additional materials and drying temperature of films on the properties of the films was investigated. With increase in mixing time, the tensile strength (TS), elongation (%E), degree of swelling (DS) and solubility (S) of the film were equilibrated. The equilibrium for TS, %E, DS and S value was 20.12 MPa, 36.98%, 2.4 and 0.19, respectively. The mixing time of equilibrium was 50 min. TS, %E, DS and S of starch/PVA blend film were examined adding glycerol (GL), sorbitol (SO) and citric acid (CA) as additives. At all measurement results, except for DS, the film adding CA was better than GL or SO because hydrogen bonding at the presence of CA with hydroxyl group and carboxyl group increased the inter/intramolecular interaction between starch, PVA and additives. Citric acid improves the properties of starch/PVA blend film compared to glycerol and sobitol. When the film was dried at low temperature, the properties of the films were clearly improved because the hydrogen bonding was activated at low temperature.     

Mechanical Property Characterization of Plasticized Sugar Beet Pulp and Poly(Lactic Acid) Green Composites Using Acoustic Emission and Confocal Microscopy

Sorbitol and glycerol were used to plasticize sugar beet pulp-poly(lactic acid) green composites. The plasticizer was incorporated into sugar beet pulp (SBP) at 0%, 10%, 20%, 30% and 40% w/w at low temperature and shear and then compounded with poly(lactic acid) (PLA) using twin-screw extrusion and injection molding. The SBP:PLA ratio was maintained at 30:70. As expected, tensile strength decreased by 25% and the elongation increased. Acoustic emission (AE) showed correlated debonding and fracture mechanisms for up to 20% w/w plasticizer and uncorrelated debonding and fracture for 30–40% sorbitol and 30% glycerol content in SBP–PLA composites. All samples had a well dispersed SBP phase with some aggregation in the PLA matrix. However, at 40% glycerol plasticized SBP–PLA composites exhibited unique AE behavior and confocal microscopy revealed the plasticized SBP and PLA formed a co-continuous two phase system.

Mechanical treatment of automobile shredder residue for its application as a fuel

Enforcement of the Automobile Recycling Law in Japan requires utilization of automobile shredder residue (ASR). However, the high contents of copper (∼5%) and chlorine (∼1%) in ASR stand in the way of practical application. We studied methods for the removal of copper and chlorine from ASR so that it could be utilized as a fuel. By compression of the ASR for solidification with an extruder, the polyvinylchloride (PVC) that covered electrical cables was softened and stripped from the copper wire. The solidified ASR was comminuted with cutter mills and classified by dry density separation. The copper content of the obtained light products was 0.2%–0.5%. Furthermore, we studied the possibility of dechlorination of the ASR by mechanochemical (MC) activation. The light product of the ASR was milled with CaO or CaCO₃. The chlorine content decreased to about one-tenth of the original value after MC activation over 8 h. Therefore, the combined processing of softening–stripping and comminution liberated the PVC-covered cables and decreased the copper content of the ASR. In addition, dechlorination of the ASR was also possible by MC activation with the addition of calcium compounds.     

Preparation and Thermo-Mechanical Characterization of Chitosan Loaded Methylcellulose-Based Biodegradable Films: Effects of Gamma Radiation

Chitosan (0.1–1%, w/w), dissolved in 2% acetic acid solution, was added into 1% methylcellulose (MC)-based formulation containing 0.5% vegetable oil, 0.25% glycerol and 0.025% Tween^?80. Films were prepared by casting. Puncture strength (PS), puncture deformation (PD), viscoelasticity coefficient and water vapour permeability (WVP) of the films were measured. The PS value of 312 N/mm was observed for MC-based films containing 0.25% chitosan. Values of PD, viscoelasticity coefficient and WVP of these films were 5.0 mm, 44.1%, and 6.0 g mm/m² day kPa, respectively. The MC-based films containing 0.25% chitosan were also exposed to gamma radiation (0.5–50 kGy). The PS of the treated films decreased significantly from 312 at 0 kGy to 201 N/mm when treated at a dose of 50 kGy. However, WVP values were not affected by increasing irradiation the dose used. The Fourier Transform Infrared spectroscopy supported the molecular interactions due to addition of chitosan in MC-based films. Thermo gravimetric analysis and differential scanning calorimetric experiments showed that thermal properties of the films were significantly improved by chitosan loading. Surface topography of the films was studied by scanning electron microscopy and found rougher due to chitosan addition.     

Environmental contamination from electronic waste recycling at Guiyu, southeast China

The disposal, recycling, and part salvaging of discarded electronic devices such as computers, printers, televisions, and toys are now creating a new set of waste problems. This study is aimed at identifying the sources and quantifying the pollution levels generated from electronic waste (e-waste) activities at Guiyu, Guangdong Province, China, and their potential impacts on the environment and human health. The preliminary results indicate that total polycyclic aromatic hydrocarbons (PAHs) in soil obtained from a printer roller dump site was 593 μg/kg dry weight (dry wt.) and in sediment from a duck pond, the PAH concentration was 514 μg/kg (dry wt.). Sediment from the Lianjiang River was found to be contaminated by polychlorinated biphenyls (743 μg/kg) at a level approaching three times the Canadian Environmental Quality Guidelines probable effect level of 277 μg/kg. Total mono- to hepta-brominated diphenyl ether homologue concentrations (1140 and 1169 μg/kg dry wt.) in soils near dumping sites were approximately 10–60 times those reported for other polybrominated diphenyl ether-contaminated locations in the world. In-house study on the open burning of cable wires showed extremely high levels of polychlorinated dibenzo-p-dioxins and dibenzofurans resulting in 12419 ng toxic equivalents (TEQ)/kg of waste input and 15 610 ng TEQ/kg for two separate tests, respectively, which were about three orders of magnitude higher than those for the open burning of household waste. High levels of Cu (712, 528, and 496 mg/kg), exceeding the new Dutch list action value, were determined for soil near the printer roller dumping area, sediment from Lianjiang River, and soil from a plastic burn site, respectively. A more thorough study is underway to elucidate the extent of contamination of toxic pollutants in different ecological compartments to establish whether these pollutants are bioaccumulated and biomagnified through food chains. Assessments of human health impacts from oral intake, inhalation, and dermal contact will be subsequently investigated. An erratum to this article is available at.     

High compressive strength of home waste and polyvinyl acetate composites containing silica nanoparticle filler

Simple mixing and hot pressing methods were used to make composites from home waste—in particular, paper and dry leaves—using polyvinyl acetate (PVAc) as an adhesive and silica nanoparticles as filler. The optimum composition for the strongest composites, in terms of compressive strength, had a mass ratio of silica nanoparticles/PVAc/(paper + dry leaves) of 3:80:280. With this mass ratio, a compressive strength of 68.50 MPa was obtained for samples prepared at a pressing temperature of 150°C, pressing pressure of 100 MPa, and pressing time of 20 min. The addition of silica nanoparticles increased the compressive strength by about 50%, compared with composites made without the addition of nanosilica (45.60 MPa). Higher compressive strength was obtained at a higher pressing pressure. At a pressing pressure of 120 MPa, pressing temperature of 150°C, and pressing time of 20 min, a compressive strength of 69.10 MPa was obtained. When the pressing time was increased to 45 min at a pressing pressure of 120 MPa, a compressive strength of 84.37 MPa was measured. A model was also proposed to explain the effects of pressing pressure and pressing time on compressive strength. The model predictions were in good agreement with the experimental data.     

Anaerobic digestion of chicken feather with swine manure or slaughterhouse sludge for biogas production

Biogas production from anaerobic digestion of chicken feathers with swine manure or slaughterhouse sludge was assessed in two separate experiments. Ground feathers without any pre-treatment were added to 42-L digesters inoculated with swine manure or slaughterhouse sludge, representing 37% and 23% of total solids, respectively and incubated at 25 °C in batch mode. Compared to the control without feather addition, total CH₄ production increased by 130% (P < 0.001) and 110% (P = 0.09) in the swine manure and the slaughterhouse sludge digesters, respectively. Mixed liquor NH₄N concentration increased (P < 0.001) from 4.8 and 3.1 g/L at the beginning of the digestion to 6.9 and 3.5 g/L at the end of digestion in the swine manure and the slaughterhouse sludge digesters, respectively. The fraction of proteolytic microorganisms increased (P < 0.001) during the digestion from 12.5% to 14.5% and 11.3% to 13.0% in the swine manure and the slaughterhouse sludge digesters with feather addition, respectively, but decreased in the controls. These results are reflective of feather digestion. Feather addition did not affect CH₄ yields of the swine manure digesters (P = 0.082) and the slaughterhouse sludge digesters (P = 0.21), indicating that feathers can be digested together with swine manure or slaughterhouse sludge without negatively affecting the digestion of swine manure and slaughterhouse sludge.     

Environmental Impact Assessment of Polylactide(PLA)/Chicken Feathers Biocomposite Materials

The aim of this study is to analyse the environmental impacts (EIs) of the process of preparation of new biocomposite materials obtained from polylactide (PLA) and chicken feathers (CFs). Two CFs stabilization methods and different percentages of CFs have been studied. The EIs of these new composites were compared to the impact of virgin PLA. Cradle-to-gate life cycle inventories were assessed for 0–35% v/v of CFs in a CFs/PLA biocomposite. Two CFs stabilization processes, autoclave and surfactant, were tested and compared with the aim to prioritize one of them from the environmental point of view. A composite plate of 184?×?184?×?2.2 mm³ was defined as the functional unit. Autoclave stabilization process exhibited lower environmental impact compared with surfactant stabilization process mainly due to both the lower requirements of electricity and water and the reduced pollution loads of the generated wastewater. Thus, the autoclave process was selected as the standard method when comparing the EIs of the proposed CFs/PLA biocomposites. In this sense, the addition of CFs to PLA matrix proportionally reduces all the EIs compared to pure PLA due to the replacement of PLA with CFs. This behaviour can be explained because the PLA production accounts for the 99% of the impact of the biocomposite. Consequently, CFs conveniently stabilized might be an alternative raw material to prepare CFs/PLA biocomposites with less environmental impact compared to pure PLA.     

Investigation of Thermoplasticity of Zein and Kafirin Proteins: Mixing Process and Mechanical Properties

Conventional direct melt mixing technology was investigated on zein and kafirin, two vegetable proteins extracted, respectively, from maize and sorghum. A lab scale internal mixer has been used to thoroughly study the thermo-plasticization process of the proteins with several plasticizers. Different compositions were investigated under different processing conditions. In particular, the lengthy procedures of forming the protein/solvent/plasticizer solution followed by drying or the protein/plasticizer emulsion followed by the precipitation of the extrudable resin, reported in the literature for these systems, were avoided and the protein and plasticizer were directly fed into the mixer to obtain a plastic-like material. The effect of plasticizer type and content and mixing process variables on the mechanical properties was analyzed. Compression molded slabs were transparent, strong and flexible, with properties similar to the cast films reported in the literature, prepared with the same type of plasticizers. However, lower plasticizer content was sufficient to produce equally flexible films, proving an enhanced plasticization efficiency of the mixing process, as compared to casting.