Biopolymer Blends Research Articles

Regulated phase separation in nanopatterned protein-polysaccharide thin films by spin coating

Patterned films are essential to the commonplace technologies of modern life. However, they come at high cost to the planet, being produced from non-renewable, petrochemical-derived polymers and utilising substrates that require harsh, top-down etching techniques. Biopolymers offer a cheap, sustainable and viable alternative easily integrated into existing production techniques. We describe a simple method for the production of patterned biopolymer surfaces and the assignment of each biopolymer domain, which allows for selective metal incorporation used in many patterning applications. Protein and polysaccharide domains were identified by selective etching and metal incorporation; a first for biopolymer blends. Morphologies akin to those observed with synthetic polymer blends and block-copolymers were realised across a large range of feature diameter (200 nm to - 20 μm) and types (salami structure, continuous, porous and droplet-matrix). The morphologies of the films were tuneable with simple recipe changes, highlighting that these biopolymer blends are a feasible alternative to traditional polymers when patterning surfaces. The protein to polysaccharide ratio, viscosity, casting method and spin speed were found to influence the final film morphology. High protein concentrations generally resulted in porous structures whereas higher polysaccharide concentrations resulted in spherical discontinuous domains. Low spin speed conditions resulted in growth of protuberances ranging from 200 nm to 22 μm in diameter, while higher spin speeds resulted in more monodisperse features, with smaller maximal diameter structures ranging from 300 nm to 12.5 μm.

Study the effect of TiO2 nanoparticles on Physical properties of Biopolymer blend

Chitosan (CH) / Poly (1-vinylpyrrolidone-co-vinyl acetate) (PVP-co-VAc) (7:3) blend [CH/(PVP-co-VAc)] reinforced with two types of nanoparticle of titanium oxide TiO2 (type I & II) were prepared by solution casting method. The nanocomposites prepared with different concentrations (1, 2, 3.5, 5, 7.5, and 10) wt%. The tests carried out were AFM, FTIR, Tensile strength, Thermal conductivity measurement, and Weight gain. The results of the AFM test showed that the roughness of the surface decreased with the addition of a small amount of nanoparticles (1 wt.%) to the CH/(PVP-co-VAc) blend. FTIR results for blend film indicates a significant degree of composition between (PVP-co-VAc) and CH molecules. Nanocomposite films indicate that the composition among polymer blends and Nano are associated with changes in intensity, shape, and position of modes. The mechanical properties of chitosan were enhanced by the addition of TiO2 nanoparticle with significant increases in tensile strength (from 47.87 MPa to 64.95 ~ 70 MPa). Because interfacial bonding and homogenous distribution between the nanoparticles and the blend were supportive of markedly improved mechanical strength. The results of thermal conductivity and water absorption showed that the highest values were achieved in the polymer blend (CH/[PVP-co-VAc]), whereas its decrease with the increase of the nanoparticle incorporation.

Tissue Engineering the Annulus Fibrosus Using 3D Rings of Electrospun PCL:PLLA Angle-Ply Nanofiber Sheets

Treatments to alleviate chronic lower back pain, caused by intervertebral disc herniation as a consequence of degenerate annulus fibrosus (AF) tissue, fail to provide long-term relief and do not restore tissue structure or function. The future of AF tissue engineering relies on the production of its complex structure assisted by the many cells that are resident in the tissue. As such, this study aims to mimic the architecture and mechanical environment of outer AF tissue using electrospun fiber scaffolds made from a synthetic biopolymer blend of poly(ε-caprolactone) (PCL) and poly(L-lactic) acid (PLLA). Initially, an aligned bilayer PCL:PLLA scaffold was manually assembled at ±30° fibers direction to resemble the native AF lamellar layers; and bovine AF cells were used to investigate the effect of construct architecture on cell alignment and orientation. Bilayer scaffolds supported cell adhesion and influenced their orientation. Furthermore, significant improvements in tensile stiffness and strength were achieved, which were within the reported range for human AF tissue. Electrospun bilayer scaffolds are, however, essentially two-dimensional and fabrication of a complete three-dimensional (3D) circular construct to better replicate the AF's anatomical structure is yet to be achieved. For the first time, a custom-built Cell Sheet Rolling System (CSRS) was utilized to create a 3D circular lamellae construct that mimics the complex AF tissue and which overcomes this translational limitation. The CSRS equipment is a quick, automated process that allows the creation of multilayered, tube-like structures (with or without cells), which is ideal for mimicking human cervical AF tissue in term of tissue architecture and geometry. Tube-like structures (6 layers) were successfully created by rolling ±30° bilayer PCL:PLLA scaffolds seeded with bovine AF cells and subsequently cultured for 3 weeks. Cells remained viable, purposefully oriented with evidence of collagen type I deposition, which is the main structural component of AF tissue. This is the first study focused on applying CSRS technology for the fabrication of a more clinically-relevant, 3D tissue engineered scaffold for AF tissue regeneration.

Synthesis and characterization of chitosan and guar gum based ternary blends with polyvinyl alcohol

Biopolymers have paramount importance in pharmaceutical applications and blended biopolymers have shown promising properties versus individual counterparts. In view of excellent performance of blended biopolymers, a novel series of blended membranes based on chitosan, guar gum and polyvinyl alcohol (CS/GG/PVA) were prepared by solution casting technique. The membranes were synthesized at different ratios of GG and CS, while keeping PVA constant. The surface morphology, structure, interaction of polymers and water absorbing capacity were determined with scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and swelling properties. FTIR exhibited intermolecular bonding between the biopolymers used for membranes preparation. SEM analysis revealed that the surface morphology depends upon the various ratios of polymers. The swelling pattern has shown that the prepared membranes were hydrophilic in nature. Results revealed that the chitosan and guar gum based ternary blends with polyvinyl alcohol have potential for controlled drug release.

Enhancement of the processing window and performance of polyamide 1010/bio‐based high‐density polyethylene blends by melt mixing with natural additives

ABSTRACTThis work reports the enhancement of the processing window and of the mechanical and thermal properties of biopolymer blends of polyamide 1010 (PA1010) and bio‐based high‐density polyethylene (bio‐HDPE) at 70/30 (w/w) achieved by means of natural additives. The overall performance of the binary blend melt‐mixed without additives was poor due to both the relatively low thermal stability of bio‐HDPE at the processing temperatures of PA1010, that is, 210–240 °C, and the lack of or poor miscibility between the two biopolymers. Gallic acid, a natural phenolic compound, was added at 0.8 parts per hundred resin (phr) of biopolymer blend to enhance the thermal stability of the green polyolefin and therefore enlarge the processing window of the binary blend. Maleinized linseed oil, a multi‐functionalized vegetable oil, was then incorporated at 5 phr to compatibilize the biopolymers and the performance of the blend was also compared with that of a conventional petroleum‐derived copolymer, namely poly[ethylene‐co‐(acrylic acid)]. The resultant biopolymer blends showed a marked enhancement in thermal stability and also improved toughness when both natural additives were combined. This work can potentially serve as a sound base study for the mechanical recycling of similar blends containing bio‐based but non‐biodegradable polymers. © 2019 Society of Chemical Industry

Effects of dicumyl peroxide on cell formation of biopolymer blend-activated carbon composite foams

Immiscible biopolymer blends of polylactic acid (PLA) and polybutylene succinate (PBS) with a weight ratio of 80/20 were compatibilized by different concentrations (0, 0.1, 0.3 and 0.5 parts per hundred resin (phr)) of dicumyl peroxide (DCP) in the presence of 3 phr of activated carbon (AC). Influences of DCP on the melt rheology at foaming temperature, cell formation and morphology and foam properties of PLA-PBS-AC composites using 5 phr of azodicarbonamide (ADC) as a blowing agent were reported. It was found that the melt viscosity, relating to the melt flow index (MFI) of PLA-PBS-AC composite foams increased with increasing DCP loadings due to more compatibility between PLA and PBS. Closed cells with thick cell walls were obtained with the addition of DCP. Also, the cell size and cell density tended to decrease by DCP adding since lower cell expansion and coalescence occurred at higher polymer surface tension. The crystallinity (Xc) and thermal properties of PLA and PBS in composite foams were almost unchanged when DCP was filled in the system. The PLA-PBS-AC composite foam having 0.3 phr of DCP provided the lowest foam density (pf) and the highest void fraction (Vf) of 0.5766 g cm3 and 54% respectively.

Evaluating the Influence of Specific Mechanical Energy on Biopolymer Blends Prepared via High-Speed Reactive Extrusion

This work studies, for the first time, the influence of specific mechanical energy (SME) on the reaction efficiency and blend’s performance during reactive extrusion of biopolymer compounds. Poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) were compounded separately with poly(propylene carbonate) (PPC) and a premade maleic anhydride (MAH) compatibilizer to achieve functionalization. Different screw speeds (reaching 1000 rpm) and flow rates were tested. Results indicated that the grafting efficiency was directly proportional to the SME imparted in the system. The PBS blends compounded at shorter times and faster speeds experienced less degradation and better mechanical properties than blends compounded at longer times. The effect was similar but less pronounced for the PLA formulations. It is possible to optimize the reactive compatibilization of biopolymer blends by means of SME calculations and that better blend performance is achieved when conducting high-speed extrusion at short residence times.

Enhanced Interfacial Adhesion of Polylactide/Poly(ε-caprolactone)/Walnut Shell Flour Composites by Reactive Extrusion with Maleinized Linseed Oil.

Novel green composites were prepared by melt compounding a binary blend of polylactide (PLA) and poly(ε-caprolactone) (PCL) at 4/1 (wt/wt) with particles of walnut shell flour (WSF) in the 10–40 wt % range, which were obtained as a waste from the agro-food industry. Maleinized linseed oil (MLO) was added at 5 parts per hundred resin (phr) of composite to counteract the intrinsically low compatibility between the biopolymer blend matrix and the lignocellulosic fillers. Although the incorporation of WSF tended to reduce the mechanical strength and thermal stability of PLA/PCL, the MLO-containing composites filled with up to 20 wt % WSF showed superior ductility and a more balanced thermomechanical response. The morphological analysis revealed that the performance improvement attained was related to a plasticization phenomenon of the biopolymer blend and, more interestingly, to an enhancement of the interfacial adhesion of the green composites achieved by extrusion with the multi-functionalized vegetable oil.

Material conservation and surface coating enhancement with starch-pectin biopolymer blend: A way towards green

The work highlights the utility of biopolymer blend as an effective corrosion inhibitor and proves its ability to improve the coating characteristics of epoxy resin on steel during acid corrosion. Biopolymer blend of starch and pectin was prepared and characterized by viscosity measurements and spectral studies. Initially conditions were optimized to get maximum inhibition efficiency of biopolymer blend for the acid corrosion control of steel. Electrochemical techniques such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) were adopted for the corrosion rate measurements. Later, same techniques were employed to study the corrosion rate of the epoxy resin coated steel before and after the addition of environmentally benign biopolymer blend. Detailed investigation of surface morphology of epoxy coated steel was carried out using scanning electron microscopy (SEM), energy dispersion X-ray (EDX) and X-Ray Diffraction (XRD) techniques.

Co-encapsulation of bioactive compounds from blackberry juice and probiotic bacteria in biopolymeric matrices

Blackberry juice (BJ) and Lactobacillus acidophilus (LA) were co-encapsulated by spray drying in three single materials: gum Arabic (GA), maltodextrin (MD) and whey protein concentrate (WPC), as well as in the 50:50 blends of these materials were also considered. After the spray drying, total phenolic compounds (TPC) and total monomeric anthocyanin content (TMAC) was higher when GA-MD blend was used as an encapsulating agent with 98.4 ± 1.0% and 99.0 ± 1.0%, respectively. FTIR analysis indicated that the BJ affected the structure of the wall material, mainly when WPC was incorporated. The viability of LA was significantly higher when WPC was used (93.3 ± 0.9%) in comparison with a single material or a blend of materials. After storage of microcapsules, the best blend of biopolymers to protect TPC and TMAC was GA-MD with values of 67.9 ± 0.6% and 81.8 ± 0.8% respectively, while WPC presented the highest protection in LA cell survival (81.2 ± 0.7%). The degradation dynamics of compounds in microcapsules was described by first-order kinetics, with degradation rates ranging between 0.06 and 0.30 week−1 for bioactives and probiotic bacteria. The overall results showed GA-MD can be considered the most viable formulation to protect bioactives and probiotic bacteria.

Effect of Ionic Liquid BMIMNO<sub>3</sub> to Chitosan-Starch Blend Biopolymer Electrolyte System

Chitosan-Starch blend biopolymer electrolyte system doped with different percentage of BMIMNO3 was prepared via solution casting technique. The crystalinity of the system was calculated using data extracted from x-ray diffraction (XRD). The film was characterized by impedance spectroscopy HIOKI 3531-01 LCR Hi-Tester to measure its ionic conductivity over a wide range of frequency between 50Hz-5MHz and at temperatures between 298 K and 378 K. The result exhibit the advantages of ionic liquid as a charge carrier and also revealed that addition of 5% of BMIMNO3 shows the highest conductivity of (2.26 +-0.96) x 10-4 Scm-1 .Conductivity-temperature relationship indicate that the system seems to obey the Vogel-Tamman-Fulcher (VTF) behaviour.

Synthesis and characterization of porous cytocompatible scaffolds from polyvinyl alcohol–chitosan

In this study, novel porous cytocompatible scaffolds with a 3D nanocomposite structure were synthesized by using nanoclay particles embedded into a biopolymer blend composed of polyvinyl alcohol (PVA) and chitosan (CS). According to the results, the Fourier transform infrared spectrum confirmed the presence of nanoclay, PVA and CS in the scaffold structure. X-ray diffraction outcomes showed the enhancement of crystalline zone in the synthesized 3D scaffolds by increasing the nanoclay content. Scanning electron microscopy (SEM) images revealed the highly porous interconnected microstructure of the scaffolds. Also, the energy-dispersive X-ray spectra verified the presence of nanoclay, PVA and CS in the sample with the highest nanoclay content. According to mechanical properties and porosity of the synthesized 3D scaffolds, compressive strength (i.e., \(3.5\pm 0.2\) MPa), elastic modulus (\(1.42\pm 0.02\) GPa) and porosity (75–82%) of the sample with the highest nanoclay content was in the range of mechanical properties and porosity of a natural trabecular bone tissue. The swelling of samples in a phosphate-buffered saline solution was less than the swelling in water. In addition, increasing the content of nanoclay decreases the percentage of swelling. Outcomes of cell culture experiments confirmed that the synthesized 3D scaffolds were not toxic and the cell attachment SEM images showed a sufficient attachment of the cell to the interconnected porous structure of the sample. Results suggest that the synthesized 3D scaffold in this study possesses proper microstructure properties and no cytotoxicity to be replaced with natural bone tissues.

Environmental Impact on Biodegradation Speed and Biodegradability of Polyethylene and Ipomoea Batatas Starch Blend

All over the world, even in developing countries, plastics have quickly become one of the most common things found around. Unsurprisingly, this has caused a major waste management problem, particularly because synthetic polymers do not break down and degrade like organic waste. As a result, an alternative is being sought out in biopolymers. This study explores the suitability of a biopolymer blend;Ipomoea batatasmixed with low density polyethylene (LDPE) at various compositions. Biodegradation of this biopolymer blend was observed periodically when produced samples ofIpomoea batatas/LDPE were buried in loamy sand over a period of 28 days. Results show that produced biopolymers are environmentally compatible and bio-degradable. It was also observed that the sample blend with equal portions by weight ofIpomoea batatas(50%) and LDPE (50%) showed the most optimum pattern of degradation. There was steady degradation over the study period and the rate of degradation observed showed sustainability.

TD‐NMR to understand water‐binding food properties

TD‐NMR to understand water‐binding food properties

Study the effect of CaCO3 nanoparticles on physical properties of biopolymer blend

Chitosan (CH) / Poly (1-vinylpyrrolidone-co-vinyl acetate) (PVP-co-VAc) blend (1:1) and nanocomposites reinforced with CaCO3 nanoparticles were prepared by solution casting method. FTIR analysis, tensile strength, Elongation, Young modulus, Thermal conductivity, water absorption and Antibacterial properties were studied for blend and nanocomposites. The tensile results show that the tensile strength and Young’s modulus of the nanocomposites were enhanced compared with polymer blend [CH/(PVP-co-VAc)] film. The mechanical properties of the polymer blend were improved by the addition of CaCO3 with significant increases in Young’s modulus (from 1787 MPa to ~7238 MPa) and tensile strength (from 47.87 MPa to 79.75 MPa). Strong interfacial bonding between the CaCO3 nanoparticles and the [CH/(PVP-co-VAc)), homogenous distribution of the nanoparticles in the polymer blend, are assistance of noticeably raised mechanical durability. The thermal conductivity of the polymer blend and CaCO3 nanocomposite films show that it decreased in the adding of nanoparticle CaCO3. The solvability measurements display that the nanocomposite has promoted water resistance. The weight gain lowered with the increase of nano CaCO3. Blending chitosan CH with (PVP-co-VAc) enhanced strength and young modules of the nanocomposites and increased the absorption of water because hydrophilic of the blended polymers films. The effect of two types of positive S.aurous and negative E. coli was studied. The results showed that the nanocomposites were effective for both types, where the activity value ranged from (12 ~ 21). The best results were found for S.aurous bacteria.

Enhancement in Thermal Stability of Polyoxymethylene (POM)-Based Biopolymer Blend Materials

In this study, we demonstrate the enhancement in thermal stability of polyoxymethylene (POM)-based biopolymer blend materials. Polyoxymethylene (POM)/Polylactic acid (PLA) blends have been used as alternative biopolymer materials for supporting environmental problems with thermal stability feature. The effects on POM biopolymer blend materials with a controlled PLA amount in their compositions under various injection conditions, were investigated by thermogravimetric analysis, dynamic mechanical analysis, and differential scanning calorimetry. The POM/PLA biopolymer blend materials showed POM phase acted as a homogeneous nucleating site for increasing PLA crystallization, which improves storage modulus of the blend materials. The decomposition temperatures of POM/PLA biopolymer blends tend to shift around 30˚C - 50˚C lower compared to the decomposition temperatures of PLA. Thus, the decomposition temperature behavior of POM/PLA blends seems to be closer to POM. The suitable ratio in POM70/PLA30 resulted in the high strength of the blend materials. The POM/PLA biopolymer blend material was tested at various injection speeds and good miscibility was obtained at an injection speed of 100 mm/s. This enhancement of thermal stability in POM/PLA blend materials should be useful in the development of high-performance bio-based thermoplastic materials.

Optimization studies for encapsulation and controlled release of curcumin drug using Zn+2 cross-linked alginate and carboxy methylcellulose blend

Biopolymers have attracted significant attention for the development of drug-carrying systems due to their high degree of biocompatibility, nontoxicity, biodegradability, and renewability. The focus of this work is to examine the optimized conditions for maximum encapsulation and release of anti-cancer drug curcumin using modified biopolymer blend beads of sodium alginate (SA) and carboxymethylcellulose (CMC). Biopolymer blend beads were prepared by mixing equal amounts of SA and CMC using normal syringe method followed by crosslinking with ZnCl2 to improve the stability of the drug carrier. The applicability of the Zn2+ Crosslinked SA/CMC for curcumin was evaluated in terms of entrapment efficiency, swelling, in vitro release and drug release kinetics. Further, pseudo-first order and pseudo-second-order kinetics and isotherm models were applied to the encapsulation data and the results demonstrate that the interaction between curcumin and the biopolymers was physio sorption. The developed biopolymer drug carriers were characterized by Fourier transform infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) with and without loading of curcumin to investigate the interactions between the curcumin drug and drug carrier. The obtained results were also analyzed and compared with pristine SA beads. The maximum encapsulation efficiency was found to be 79.75% and 93.07% for SA and SA/CMC blend respectively for the formulations. The in vitro drug release studies were carried out at pH 7.4 in phosphate buffer for 8 h at 37 °C and the results demonstrate the cumulative percentage of curcumin release was increased with increasing carrier concentration. Among several kinetic models of drug release, Korsmeyer-Peppas model exhibited high correlation coefficient (r2) for both the SA and the SA/CMC.

Ductility and Toughness Improvement of Injection-Molded Compostable Pieces of Polylactide by Melt Blending with Poly(ε-caprolactone) and Thermoplastic Starch.

The present study describes the preparation and characterization of binary and ternary blends based on polylactide (PLA) with poly(ε-caprolactone) (PCL) and thermoplastic starch (TPS) to develop fully compostable plastics with improved ductility and toughness. To this end, PLA was first melt-mixed in a co-rotating twin-screw extruder with up to 40 wt % of different PCL and TPS combinations and then shaped into pieces by injection molding. The mechanical, thermal, and thermomechanical properties of the resultant binary and ternary blend pieces were analyzed and related to their composition. Although the biopolymer blends were immiscible, the addition of both PCL and TPS remarkably increased the flexibility and impact strength of PLA while it slightly reduced its mechanical strength. The most balanced mechanical performance was achieved for the ternary blend pieces that combined high PCL contents with low amounts of TPS, suggesting a main phase change from PLA/TPS (comparatively rigid) to PLA/PCL (comparatively flexible). The PLA-based blends presented an “island-and-sea” morphology in which the TPS phase contributed to the fine dispersion of PCL as micro-sized spherical domains that acted as a rubber-like phase with the capacity to improve toughness. In addition, the here-prepared ternary blend pieces presented slightly higher thermal stability and lower thermomechanical stiffness than the neat PLA pieces. Finally, all biopolymer pieces fully disintegrated in a controlled compost soil after 28 days. Therefore, the inherently low ductility and toughness of PLA can be successfully improved by melt blending with PCL and TPS, resulting in compostable plastic materials with a great potential in, for instance, rigid packaging applications.

54] Preparation of biopolymer (dextran) and gentamycin blend against multi-drug resistant bacterial infections associated with catheters

ObjectiveTo characterise and investigate the toxicity of biopolymer dextran (from local isolates of Leuconostoc mesenteroides ssp.) and gentamycin blend against multi-drug resistant bacterial infections associated with catheters.

A Hierarchical Model To Understand the Processing of Polysaccharides/Protein-Based Films in Ionic Liquids.

In recent years, biomaterials from abundant and renewable sources have shown potential in medicine and materials science alike. In this study, we combine theoretical modeling, molecular dynamics simulations, and several experimental techniques to understand the regeneration of cellulose/silk-, chitin/silk-, and chitosan/silk-based biocomposites after dissolution in ionic liquid and regeneration in water. We propose a novel theoretical model that correlates the composite's microscopic structure to its bulk properties. We rely on modeling non-cross-linked biopolymers that present layer-like structures such as β-sheets and we successfully predict structural, thermal, and mechanical properties of a mixture of these biomolecules. Our model and experiments show that the solubility of the pure substance in the chosen solvent can be used to modulate the amount of crystallinity of the biopolymer blend, as measured by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Thermogravimetric analysis (TGA) shows that the decomposition temperature of the blended biocomposites compared to their pure counterparts is reduced in accordance with our theoretical predictions. The morphology of the material is further characterized through scanning electron microscopy (SEM) and shows differently exposed surface area depending on the blend. Finally, differential scanning calorimetry (DSC) is performed to characterize the residual water content in the material, essential for explaining the regeneration process in water. As a final test of the model, we compare our model's prediction of the Young's modulus with existing data in the literature. The model correctly reproduces experimental trends observed in the Young's modulus due to varying the concentration of silk in the biopolymer blend.