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Highlights • All materials were obtained by melt processing in internal mixer. • The effect of type and amount of plasticizer and the MCC influence were analysed. • An uniform matrix, good filler dispersion and matrix-MCC interaction were observed. • The isosorbide-TPS crystallinity was time-stable, no matter the plasticiser amount. • The isosorbide-TPS showed better thermal properties, enhanced when MCC was used. Abstract Innovative, green and fully biodegradable biocomposites, based on plasticized corn starch, were prepared by melt processing and filled with microcrystalline cellulose (MCC). Isosorbide and glycerol were used as plasticizers. The effect of the type and content of the plasticizer and the filler addition on processing, surface morphologies, crystallinity and thermal stability were investigated. Aged materials were analyzed too to study the retrogradation phenomena along the time. The processing using isosorbide required lower temperatures but greater shear and processing times leading to more homogeneous biocomposites. With isosorbide, higher crystallinity and no retrogradation signals were observed as clearly occurred with glycerol. The thermal stability of biocomposites was high too. These properties enhanced in a greater extent when the isosorbide content was 35% and with the MCC incorporation, the last due to a good adhesion of MCC to the matrix. These biocomposites could be a good option for packaging applications. [ABSTRACT FROM AUTHOR]

Highlights • PVA/starch (non-sonicated and sonicated) blends film were reinforced by BC fibers. • Opacity, tensile testing, XRD, FTIR, and TGA were used to characterize the films. • Sonicated blends film shows lower tensile strength than the non-sonicated one. • Sonicated biocomposite film had better performance than the non-sonicated one. Abstract This paper reports the characterization of polyvinyl alcohol (PVA)/cassava starch biocomposites. The cassava starch gel with or without ultrasonic probe treatment was mixed with PVA gel then short bacterial cellulose fibers were added. The presence of the sonicated starch gel in the PVA resulted in low thermal and moisture resistance, and low transparency of the blend film. After adding the fibers thermal and moisture resistance of the sonicated biocomposite increased due to stronger hydrogen bonding between the fibers and the matrix. Tensile strength of sonicated biocomposite with 10 g fibers increased 215% compared to the sonicated blend. However, addition of the fibers to the non-sonicated blend did not significantly increase mechanical and thermal properties or moisture resistance of the biocomposite. Opacity of the non-sonicated biocomposite was lower than that of the sonicated one. [ABSTRACT FROM AUTHOR]

Biocomposites of potato starch/poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microparticles were prepared through the solvent casting method. Glycerol was used as a plasticizer. The effects of concentrations of PHBV microparticles as filler and glycerol on crystallinity behavior, surface morphology, dynamic mechanical properties, and thermal stability were studied. Humidity absorption and the water vapor transmission rate (WVTR) were investigated as well. Wide angle X-ray scattering (WAXS) patterns revealed that the plasticizing process occurred successfully. Scanning electron microscopy (SEM) micrographs exhibited good homogeneity of the surfaces for the biocomposites with a lower glycerol concentration. Dynamic mechanical analysis (DMA) results confirmed the reinforcing effect of PHBV microparticles inside the matrix. Thermogravimetric analysis (TGA) indicated that the presence of PHBV microparticles increased the thermal stability of the starch. Results of humidity absorption tests showed that the high hydrophilicity of the starch was reduced once the PHBV microparticles had been incorporated. Also, increasing PHBV microparticles reduced the water vapor transmission rate. However, samples with reduced glycerol content absorbed less humidity and showed a lower water vapor transmission rate. [ABSTRACT FROM AUTHOR]

Cellulosic material from coffee husk has not been previously studied despite being a potential source of reinforcing agents for different applications. This material has been extracted and characterised from coffee husk, in parallel with previously studied rice husk. Samples have been analysed as to their ability to obtain cellulosic fibres and cellulose nanocrystals (CNC) by applying alkali and bleaching treatments and final sulphuric acid hydrolysis. Microstructural changes were analysed after treatments, and the size and aspect ratio of CNCs were determined. Crystallinity and thermal stability of both materials progressed in line with the enrichment in cellulosic compounds. The CNC aspect ratio was higher than 10, which confers good reinforcing properties. These were tested in thermoplastic starch films, whose elastic modulus increased by 186 and 121% when 1 wt% of CNCs from rice and coffee husks, respectively, was incorporated into the matrix. Coffee husk represents an interesting source of cellulosic reinforcing materials. [ABSTRACT FROM AUTHOR]

Alginate derived from seaweed is a natural polysaccharide able to form stable gel through carbohydrate functional groups largely used in the food and pharmaceutical industry. This article deals with the use of sodium alginate as an adhesive binder for wood fibres/textile waste fibres biocomposites. Several aldehyde-based crosslinking agents (glyoxal, glutaraldehyde) were compared for various wood/textile waste ratios (100/0, 50/50, 60/40, 70/30 and 0/100 in weight). The fully biomass derived composites whose properties are herewith described satisfy most of the appropriate requirements for building materials. They are insulating with a thermal conductivity in the range 0.078–0.089 W/m/K for an average density in the range 308–333 kg/m3 according to the biocomposite considered. They are semi-rigid with a maximal mechanical strength of 0.84 MPa under bending and 0.44 MPa under compression for 60/40 w/w wood/textile waste biocomposites with a glutaraldehyde crosslinking agent. [ABSTRACT FROM AUTHOR]

Cellulose carbamate (CC) was synthesized via hydrothermal process and mixed with graphene oxide (GO) to form a homogeneous cellulose matrix nanocomposite films. The properties of CC/GO nanocomposite films fabricated using simple solution-mixing method with different GO loadings were studied. Transmission electron microscope analysis showed the exfoliation of self-synthesized GO nanosheets within the CC matrix. X-ray diffraction results confirmed the crystalline structure of CC/GO films as the CC/GO mass ratio increased from 100/0 to 100/4. The mechanical properties of CC/GO film were significantly improved as compared to neat CC film. From thermogravimetric analysis result, the introduction of GO enhanced the thermal stability and carbon yields. The 3D homogeneous porous structures of the CC/GO films were observed under Field emission scanning electron microscope. These improvements in nanocomposite film properties could be confirmed by Fourier transform infrared spectroscopy due to the strong and good interactions between CC and GO. [ABSTRACT FROM AUTHOR]

In this study, surface-modified grinded coconut waste (CW) particles were used as bio-fillers to prepare polymeric composite materials with enhanced properties. Epoxy resin modified with acrylated and epoxidized soybean oil (AESO) was used as the polymer matrix. Two different strategies, namely chemical treatment and plasma enhanced chemical vapor deposition (PECVD) were utilized to modify the surface of CW particles for using them as compatible bio-fillers in composite preparation. Chemical modification involved the treatment of CW particles in a highly alkali NaOH solution, while PECVD modification involved coating of a thin film of hydrophobic poly(hexafluorobutyl acrylate) (PHFBA) around individual CW particle surfaces. Untreated and surface-modified CW particles were used in 10–50 wt% for preparation of epoxy composites. FTIR analysis was performed to study the effect of modification on the structures of particles and as-prepared composites. The composite morphologies were investigated by XRD and SE. TGA test was conducted to study the thermal behavior of the composites. Also, the effects of CW particle surface modification on the mechanical and water sorption properties of epoxy resin composites were investigated in detail. It was observed that PECVD-treated CW particles had much more positive effects on the thermal, mechanical, wettability and flammability properties of composites. [ABSTRACT FROM AUTHOR]

We prepared biodegradable P(MAA-co-MMA)-starch composite as carrier matrix for the immobilization of l -asparaginase ( l -ASNase), an important chemotherapeutic agent in acute lymphoblastic leukemia. Chemical characteristics and thermal stability of the prepared composites were determined by FT-IR, TGA, DTA and, DSC, respectively. Also, biodegradability measurements of P(MAA-co-MMA)-starch composites were carried out to examine the effects of degradation of the starch. Then, l -ASNase was immobilized on the P(MAA-co-MMA)-starch composites. The surface morphology of the composite before and after immobilization was characterized by SEM, EDX, and AFM. The properties of the immobilized l -ASNase were investigated and compared with the free enzyme. The immobilized l -ASNase had better showed thermal and pH stability, and remained stable after 30 days of storage at 25 °C. Thus, based on the findings of the present work, the P(MAA-co-MMA)-starch composite can be exploited as the biocompatible matrix used for l -ASNase immobilization for medical applications due to biocompatibility and biodegradability. [ABSTRACT FROM AUTHOR]

Biocomposites were synthesized by dispersing bentonite (Bent) clay in a biopolymer namely alginate (Alg) and cross-linked with bi (Ca 2+ ), tri (Ce 3+ ) and tetravalent (Zr 4+ ) metal ions viz., Ca@AlgBent, Ce@AlgBent and Zr@AlgBent composites respectively. The synthesized biocomposites were characterized by various instrumental techniques like FTIR, SEM and EDAX. Cr(VI) sorption capacities (SCs) of the biocomposites Ca@AlgBent, Ce@AlgBent and Zr@AlgBent were examined by batch process. Various adsorption influencing factors viz., contact time, dosage of the sorbent, pH of the medium, temperature, presence of common co-ions and initial Cr(VI) concentration were studied. Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherm models were adopted to examine the adsorption equilibrium. Kinetics of the sorption process was carried out by pseudo-first-order and pseudo-second-order models. The nature of the sorption process was explained using thermodynamic parameters like ΔS°, ΔG° and ΔH° and a possible mechanism for the sorption of Cr(VI) onto the biocomposites was given. The application of the biocomposites at field conditions was also examined by testing it with industrial water. The regeneration studies were carried to know about the reusability of the biocomposites. [ABSTRACT FROM AUTHOR]

Biocomposites suitable for short-life applications such as food packaging were prepared by melt processing and investigated. Biocomposites studied are wheat starch plasticized with two different molecular weight polyols (glycerol and sorbitol) and reinforced with various amounts of microcrystalline cellulose. The effect of the plasticizer type and the filler amount on the processing properties, the crystallization behavior and morphology developed for the materials, and the influence on thermal stability, dynamic mechanical properties and water absorption behavior were investigated. Addition of microcrystalline cellulose led to composites with good filler-matrix adhesion where the stiffness and resistance to humidity absorption were improved. The use of sorbitol as a plasticizer of starch also improved the stiffness and water uptake behavior of the material as well as its thermal stability. Biodegradable starch-based materials with a wide variety of properties can be tailored by varying the polyol plasticizer type and/or by adding microcrystalline cellulose filler. [ABSTRACT FROM AUTHOR]

We developed tricalcium phosphate-chitosan-fucoidan biocomposite scaffold (TCP-Ch-Fu) by using the freeze-drying technique. The fabricated biocomposite scaffolds were analyzed by spectroscopy and porosity measurement. The biomechanical properties of scaffolds were assessed by compression test and the results suggested that the incorporation of Fucoidan into the biocomposite improves the compression strength of scaffolds. Biomineralization of scaffolds was evaluated by soaking them in simulated body fluid and the results revealed that the addition of Fucoidan into the scaffolds enhanced the formation of apatite layer on the surface of biocomposite after 7 days of immersion. Alamar Blue assay confirmed that the cell viability of human-derived bone marrow stromal cell was superior in the TCP-Ch-Fuscaffold. The addition of Fucoidan to TCP-Ch increased the release of osteocalcin, confirming that it can support osteogenic differentiation of human mesenchymal stromal cells in in vitro culture. Thus, TCP-Ch-Fu could be a potential candidate for bone-tissue engineering applications. [ABSTRACT FROM AUTHOR]

Nowadays, composite materials are widely used in different sectors owing to their improved mechanical and functional properties compared to bulk materials and efficient manufacturing processes. Nevertheless, the majority of these materials are still petroleum-based, which is incompatible with the recent environmental awareness. As a result, in the current study, a fully biomass-based composite material was produced employing poly(furfuryl alcohol) (PFA) as a bio-based matrix coupled with cellulose powder as fillers and processing aid agent. The addition of cellulose powder increased the viscosity of the uncured composite paste and conferred it a shear-thinning thixotropic making it suitable for 3D printing using the liquid deposition modeling technique (LDM). After curing, the combination of these raw materials yields a renewable and cost-effective composite for additive manufacturing by the LDM technique with high interlayer and interfilament adhesion, good mechanical performances, and adequate shape fidelity. [Display omitted] [ABSTRACT FROM AUTHOR]

Biocomposites with tunable properties were successfully prepared through ionic assembly between anionic carboxymethyl cellulose (CMC) and cationic copolymers (quaternized poly( l -lactide)-block-poly N , N -dimethylamino-2-ethyl methacrylate) (PLA- b -PDMAEMA). The quaternized PDMAEMA segment not only works as a compatibilizer between hydrophilic CMC and hydrophobic PLA, but also acts as a lubricant between these two rigid biopolymers. The 1 H NMR (nuclear magnetic resonance) spectra demonstrated successful synthesis of PLA- b -PDMAEMA with controlled molecular weight of PDMAEMA segment. The results from scanning electronic microscopy (SEM) and Fourier transform infrared spectrometry (FTIR) verified the interaction between quaternized copolymer micelles and anionic CMC networks. The resultant biocomposite could form a transparent and uniform film after casting. Both storage moduli and maximum degradation temperature of PLA/CMC composites were increased with the reduction of molecular weight of PDMAEMA segments. It suggests that the properties of biocomposite materials can be tailored by adjusting the chain length of inclusive PDMAEMA segment. [ABSTRACT FROM AUTHOR]

The aim of this study was to improve the miscibility between fillers and polymer through modifying the face of graphene oxide ( GO ). In order to compare the effects of GO and modified graphene oxide ( MGO ) to sodium alginate ( SA ), sodium alginate/graphene oxide ( SA/GO-n ) and sodium alginate/modified graphene oxide ( SA/MGO-n ) biocomposite films were prepared, then the interaction between nanofillers and matrix was evaluated. The structure, morphologies and properties of biocomposites were characterized by Fourier transform infrared ( FTIR ) spectroscopy, X-ray diffraction ( XRD ), thermal gravimetric analysis ( TGA ), Ultraviolet–visible ( UV–vis ), scanning electron microscopy ( SEM ) and mechanical tests. The results revealed that strong interactions existed between GO ( MGO ) and SA . Compared with neat SA film, the maximum level of Young's moduli ( E ), tensile strength ( σ b ) and elongation at break ( ɛ b ) of the SA/MGO biocomposites improved by 37.8%, 68.4% and 44.9%, while that of the SA/GO biocomposites improved by 19.6%, 44% and 36.5%. [ABSTRACT FROM AUTHOR]

This article focuses on the development of eco-friendly adsorbent by alginate (Alg) bioencapsulating nano-hydroxyapatite (n-HAp) namely n-HApAlg composite for defluoridation studies in batch mode. n-HAp powder utilized as a promising defluoridating material, but it causes a significant pressure drop during field applications. To overcome such technological bottlenecks, n-HApAlg composite was synthesized. The defluoridation capacity (DC) of synthesized n-HApAlg composite possesses an enhanced DC of 3870mgF−/kg when compared to n-HAp and calcium alginate (CaAlg) composite which possess DC of 1296 and 680mgF−/kg, respectively. The biocomposite features were characterized using FTIR and SEM with EDAX analysis. The various adsorption influencing parameters like contact time, pH, co-anions, initial fluoride concentration and temperature were optimized. The adsorption process was enlightened by various isotherms and kinetic models. The suitability of the biocomposite at field conditions was also tested. [ABSTRACT FROM AUTHOR]

An insoluble biocomposite composed of potato starch and chitosan was prepared by microwave treatment. The effect of pH on swelling (liquid absorption) behavior of the composites was investigated at pH 2, pH 6.8 and pH 12. Analysis revealed that the solution uptake ratio of composites depends both on the aqueous pH value and the content of the chitosan. Composites exhibited a relatively high swelling ratio at pH environments lower than the pKa of amine groups on chitosan (about 6.3). Glucose analysis by ion exchange chromatography showed that there was little hydrolysis of such composites at low pH. When immersed in the same pH solution, composites with higher chitosan content exhibited higher swelling ratios. The microstructure of composites produced was also investigated by FE-SEM. [ABSTRACT FROM AUTHOR]

Abstract: Polyaniline/iota-carrageenan (ι-CGN) biocomposites were synthesized via in situ methodology using ammonium persulfate as the oxidizing agent. Both ionic (band at 1131cm−1) and hydrogen bond (bands at 2500 and 3500cm−1) interactions between polyaniline and ι-CGN were determined by infrared spectroscopy. Such intermolecular interactions provided the biocomposites with a cross-linked structure that provided the materials with hydrogel behavior. Biocomposite electro-conductivity, determined by the 4-probe technique, was in the range of semiconductors (10−3 to 10−2 Scm−1); whereas electro-activity, assessed by cyclic voltammetry, showed the oxidation–reduction transitions typical of polyaniline. Based on the properties of polyaniline and ι-CGN, some applications for the new materials in the field of biosensor design, electrochemical capacitors, or tissue engineering scaffolds are possible. It is worth saying that both electro-conductive and electro-active properties of polyaniline/ι-CGN biocomposites are reported here for the first time. [Copyright &y& Elsevier]

Highlights: [•] Films with adjustable loading capacity of carvacrol have been developed. [•] HP-β-cyclodextrins enhanced sorption of carvacrol by chitosan films. [•] Sorption properties of films depended on plasticization by glycerol and moisture. [•] HP-β-cyclodextrins improved mechanical resistance and water vapour barrier properties of films. [•] HP-β-cyclodextrins delayed thermal degradation of chitosan films. [ABSTRACT FROM AUTHOR]

Highlights: [•] Adsorption of cationic latex provides a novel approach for modifying CTMP fibers. [•] As-modified CTMP is very effective in reinforcing polypropylene-based biocomposite. [•] Mechanical properties were improved significantly at a low dosage of latex addition. [•] Modified cellulose fiber improved the computability between fiber and PP matrix. [•] Synergetic effect on promoting the crystallization of PP was observed. [ABSTRACT FROM AUTHOR]

Abstract: We describe the mechanical defibrillation of bacterial cellulose (BC) followed by the dry-cast generation of reconstituted BC films (RBC). Xyloglucan (XGT), extracted from tamarind seeds, was incorporated into the defibrillated cellulose at various compositions, and new films were created using the same process. Microscopy and contact angle analyses of films revealed an increase in the microfibre adhesion, a reduced polydispersity in the diameters of the microfibrils and increased hydrophobic behaviour as a function of %XGT. X-ray diffraction analysis revealed changes to the crystallographic planes of the RBC and the biocomposite films with preferential orientation along the (110) plane. Compared with BC, RBC/XGT biocomposite with 10% XGT exhibited improvement in its thermal properties and in Young''s modulus. These results indicated a reorganisation of the microfibres with mechanical treatment, which when combined with hydrocolloids, can create cellulose-based materials that could be applied as scaffolding for tissue engineering and drug release. [Copyright &y& Elsevier]

Abstract: Micro/nanofibrous substrates have been widely used for tissue regeneration because of their similarities to extracellular matrix components and their high surface area, which facilitates attachment and proliferation of cells. Phlorotannin, the main component of the brown alga Ecklonia cava, contains various growth factors that promote the regeneration of various tissues, including bone, by stimulating alkaline phosphatase (ALP) activity and inducing calcium deposition. Despite the benefits of phlorotannin in tissue regeneration, the activity of phlorotannin as a component of micro/nanofibres of various compositions has not yet been investigated. Here, we fabricated electrospun polycaprolactone (PCL)/phlorotannin micro/nanofibres containing different phlorotannin concentrations (1, 3, and 5wt%) and determined their physical properties, including water contact angle, water absorption, and mechanical properties. Owing to their hydrophilicity and water absorption ability, phlorotannin-containing fibrous mats exhibited outstanding wettability compared with pure PCL fibrous mats. The biocompatibility of the mats was examined in vitro using osteoblast-like cells (MG63). Cell viability, ALP activity, and calcium deposition were assessed. The cells distributed more widely and proliferated to a greater degree on PCL/phlorotannin mats compared with pure PCL mats. In addition, cell viability (at 5wt% phlorotannin), total protein content, ALP activity, and calcium deposition were higher with PCL/phlorotannin mats than with pure PCL mats. These results suggest that electrospun PCL/phlorotannin is a promising bioactive material for enhancing bone tissue growth. [Copyright &y& Elsevier]

Abstract: In this study, we designed a new biocomposite comprising electrospun polycaprolactone (PCL)/fucoidan, in which the fucoidan has various beneficial biological functions, including anticoagulant, antiviral, and immunomodulatory activity. To obtain the composite scaffolds, a mixture of PCL and fucoidan was electrospun using various compositions (1, 2, 3, and 10wt.%) of fucoidan powders. The resultant electrospun composites exhibited improved tensile modulus and strength for limited weight fractions (<10wt.%) of fucoidan when compared with the pure PCL fiber mats. In addition, the biocomposites showed dramatic hydrophilic properties at >3wt.% of fucoidan in the PCL/fucoidan. The biocompatibility of the electrospun mats was examined in vitro using osteoblast-like cells (MG63). Total protein content, alkaline phosphatase activity, and calcium mineralization were assessed. Scanning electron microscopic images showed that the cells were distributed more widely and were agglomerated on PCL/fucoidan mats compared with pure PCL mats. In addition, total protein content, alkaline phosphatase activity, and calcium mineralization were higher with PCL/fucoidan mats than with pure PCL mats. These observations suggest that fucoidan-supplemented biocomposites would make excellent materials for tissue-engineering applications. [Copyright &y& Elsevier]

Abstract: Biocomposites composed of poly(ɛ-caprolactone) (PCL) fibers and chitosan were obtained by two different fabrication methods: a two-step layer-by-layer technique and a co-electrospinning process. Fourier transform infrared spectroscopy and electron microscopy indicated that chitosan powders were embedded in the electrospun PCL mat. The resulting composites exhibited improved mechanical properties with an increase of about 75% in Young''s modulus when compared with the pure PCL fiber mats. In addition, the fabricated biocomposites showed various synergistic effects including enhanced water absorption and hydrophilic properties. The biological response of mesenchymal stem cells (MSCs) on the biocomposites was superior to that on pure PCL in terms of improved cell attachment, higher proliferation, and morphological homogeneity. After 7 days of culture, cell proliferation was about 25% greater than on pure PCL. These observations suggest that chitosan-supplemented biocomposites would make excellent materials for tissue engineering applications. [Copyright &y& Elsevier]

Abstract: Environmentally friendly biocomposites were successfully prepared by dissolving chitosan and cellulose in a NaOH/thiourea solvent with subsequent heating and film casting. Under the considered conditions, NaOH/thiourea led to chain depolymerization of both biopolymers without a dramatic loss of film forming capacities. Compatibility of both biopolymers in the biocomposite was firstly assessed through scanning electron microscopy, revealing an intermediate organization between cellulose fiber network and smoothness of pure chitosan. DSC analyses led to exothermic peaks close to 285 and 315°C for the biocomposite, compared to the exothermic peaks of chitosan (275°C) and cellulose (265 and 305°C), suggesting interactions between chitosan and cellulose. Contact angle analyses pointed out the deformation that can occur at the surface due to the high affinity of these materials with water. T 2 NMR relaxometry behavior of biocomposites appeared to be dominated by chitosan. Other properties of films, as crystallinity, water sorption isotherms, among others, are also discussed. [Copyright &y& Elsevier]

Abstract: In this study synthesis and characterization of biopolymer/clay biocomposites was aimed using naturally occurring polysaccharide (xylan) as biopolymer and montmorillonite type clay (NaMt). Xylan was extracted from corn cobs via alkaline oxidative treatment. Maximum solubility of xylan was determined as 1% (w/v) in water at room temperature. Thus synthesis was realized following two routes; first NaMt concentration was kept constant at 2.0×10−2 g/ml and xylan concentration was changed. Latter xylan concentration was kept constant at 1.0×10−2 g/ml and NaMt concentration was changed. Natural xylan, NaMt and biocomposites were examined in terms of their spectral, electrokinetic, rheologic, morphologic and thermal properties. Results showed that lower amounts of xylan interacted with NaMt on the surface, however, when the xylan amount was increased also intercalation of NaMt has occurred. Biocomposites showed better thermal and rheologic behaviors with respect to the starting materials. [Copyright &y& Elsevier]

Abstract: This review deals with a recent study of the literature on the various aspects of cellulosic fibres and biocomposites. Cellulosic fibre reinforced polymeric composites are finding applications in many fields ranging from construction industry to automotive industry. The pros and cons of using these fibres are enumerated in this review. The classification of composites into green composites, hybrid biocomposites and textile biocomposites are discussed. New developments dealing with cellulose based nanocomposites and electrospinning of nanofibres have also been presented. Recent studies pertaining to the above topics have also been cited. Finally, the applications of cellulosic fibre reinforced polymeric composites have been highlighted. [Copyright &y& Elsevier]

Abstract: Chitosan polymer was added to the montmorillonite (MMT) dispersions in different concentrations in the range of 1×10−2–50×10−2 g/L (in 1% acetic acid solution). The rheological behaviours and colloidal properties of the clay dispersions were determined as a function of increasing polymer concentration. The studies on zeta potential measurements indicated that chitosan attached on the surface of clay particles. XRD analyses displayed that organic molecules did not enter enough sufficiently into the layers of clay structures. In the second part of the study, the rheological behaviour of 1g/L chitosan dispersion in 1% acetic acid solution was investigated. Flow curves were analyzed using the Bingham model. The MMT/chitosan dispersions prepared at concentrations in a range of 1–50g/g, and then rheological and electrokinetic measurements were repeated for these samples and studied together with the first measurements. The characterization with different methods (FTIR, AFM, DSC, and TGA) on chitosan-MMT biocomposite systems was examined. [Copyright &y& Elsevier]

Abstract: This paper is focused on the analysis of the thermal and mechanical behaviour of processed biocomposites (biodegradable composites). These materials have been created by extrusion and injection moulding. The matrix, a biodegradable and aromatic copolyester (polybutylene adipate-co-terephthalate), has been fully characterised (NMR, SEC). The lignocellulosic materials used as fillers are a by-product of an industrial fractionation process of wheat straw. Different filler fractions have been selected by successive sieving, and then carefully analysed (granulometry, chemical structure). Cellulose, lignin, and hemicellulose contents have been determined through different techniques. The biocomposites thermal behaviour has been investigated by TGA (thermal degradation) and DSC (transition temperatures, crystallinity). These materials present good mechanical behaviour due to high filler-matrix compatibility. The impacts of filler content, filler size and the nature of each fraction have been analysed. To predict the mechanical behaviour, Takayanagi’s equation seems to provide an accurate answer to evaluate the modulus in a range, 0–30wt% of fillers. [Copyright &y& Elsevier]

Abstract: The paper is focused on the analysis of the behaviour of biocomposites (biodegradable composites) which are reinforced with different fillers fractions, with varying lignin contents. These materials have been carried-out by extrusion and injection moulding. The matrix, an aromatic copolyester (polybutylene adipate-co-terephthalate), is biodegradable. The lignocellulose fillers are a by-product of an industrial fractionation process of wheat straw. From the raw agro-material and by lignin extractions, various fillers fractions have been obtained by varying the fractionation conditions, both on the liquid media (aqueous or organic) and on the temperature. The fillers lignin contents vary from 30 to 14wt% with a resultant increase of the cellulose content. We have analysed the impact of the different extraction conditions on the fillers surface and size distribution, and also on the final thermal and mechanical properties of the biocomposites. These materials present significant differences of behaviour which can fulfil some requirements for applications, such as non-food packaging or other short-lived applications (agriculture, sport …) where long-lasting polymers are not entirely adequate. [Copyright &y& Elsevier]

Abstract: A series of environmentally friendly glycerol plasticized starch (PS) biocomposites were successfully prepared, using ramie cellulose nanocrystalites (RN) of 0–40wt% as fillers. The ramie cellulose nanocrystalites, having lengths of 538.5±125.3nm and diameters of 85.4±25.3nm on average, were prepared from ramie fibers by acid hydrolysis. The morphology, thermal behavior and mechanical properties of the resulting composites were investigated by scanning electron microscopy, differential scanning thermal analysis, dynamic mechanical thermal analysis, and measurements of mechanical properties and water absorption. The results indicate that the synergistic interactions between fillers and between filler and PS matrix play a key role in reinforcing the composites. The PS/RN composites, conditioned at 50% relative humidity, increases, respectively, in both tensile strength and Young''s modulus from 2.8MPa for PS film to 6.9MPa and from 56MPa for PS film to 480MPa with increasing RN content from 0 to 40wt%. Further, incorporating RN fillers into PS matrix also leads to a decrease in water sensitivity for the PS based biocomposites. [Copyright &y& Elsevier]

• BC and HA were covalently crosslinked by BDDE. • Crosslinked BC/HA composites exhibited a denser and smoother surface. • BDDE crosslinking improved water retention capability, dimensional stability, and elongation at break of BC/HA composites. • Crosslinked BC/HA composites significantly promoted cell proliferation. Bacterial cellulose (BC) is a good material candidate for wound dressing because of its fine 3-D network structure, high mechanical strength and water holding capability, and good biocompatibility. In this study, a composite hydrogel was prepared by using 1,4-butanediol diglycidyl ether (BDDE) to cross-link BC and hyaluronic acid (HA). Cross-linked BC/HA composites exhibited a denser and smoother surface. This dense morphology improved water retention capability and dimensional stability. BDDE cross-linked BC/HA composite with 2% HA and 1% BDDE showed better overall properties, including water stability (12.7 % water solubility), mechanical properties (tensile strength: ∼ 0.61 MPa and Young's modulus: ∼1.62 MPa) and thermal stability (maximum degradation temperature: 360 °C), as compared to BC/HA without crosslinking. In addition, cell toxicity assays and morphology indicated the BDDE cross-linked BC/HA composite significantly promoted cell proliferation and adhesion. This chemically cross-linked BC/HA composite may have many new biomedical applications in wound care. [ABSTRACT FROM AUTHOR]

The surface initiated ring opening polymerization (SI-ROP) of cellulose nanofibers (CNF) with rac -Lactide under mild conditions using N,N -dimethyl aminopyridine (DMAP) was investigated. The influence of catalyst amount, monomer-to-initiator (cellulose surface –OH groups) ratio, temperature, and cellulose preconditioning (lyophilization vs solvent exchange) were studied to determine the best SI-ROP conditions, and to understand the effect of the parameters on grafting efficiency. The fibers modified after lyophilization had a PLA content comparable to those obtained with traditional metal catalysts (e.g. tin-(II)ethylhexanoate). Starting from a stable dispersion of CNF in dichloromethane obtained through solvent-exchange showed better results at low catalyst amounts. Furthermore, DMAP was readily removed from the products whereas metal catalysts can be hard to remove from the final material, potentially shortening the material lifespan and making it unfit for some applications. Therefore, the use of an easily removable and more efficient organocatalyst can be considered a good alternative to metal catalysts. [ABSTRACT FROM AUTHOR]

• Two different levan-based biocomposites were investigated. • Montmorillonite clay and bovine serum albumin were used in the biocomposite. • The levan/MMT composite displayed an improved thermal and rheological behavior. • The levan/BSA nanoparticle showed a slow and controlled release of the BSA. • Levan-based biocomposites could be exploited in the medicinal fields. Here, two kinds of polysaccharide-based biocomposites were investigated. The enzymatically synthesized levan from Erwinia amylovora was applied as the matrix, while montmorillonite clay and bovine serum albumin (BSA) were used as additive in the biocomposite. To examine the properties of levan/MMT biocomposite, we choose different ratios between levan and MMT to implement the surface morphology observation, thermal property analysis, and rheological behavior determination. As a result, the levan/MMT biocomposite in a 2:1 blending ratio showed a significant improvement both in the thermal and rheological properties. Meanwhile, the 0.1 % levan/BSA nanoparticle showed the highest encapsulation capacity and surface charge as 53.13 ± 2.64 % and +3.92 ± 0.43 mV. Last but not least, the levan/BSA nanoparticle exhibited a slower and controlled release of the BSA from the system. All of these results indicated a potential application of levan-based biocomposite and nanoparticle. [ABSTRACT FROM AUTHOR]