scholarly journals Biocomposites of Low-Density Polyethylene Plus Wood Flour or Flax Straw: Biodegradation Kinetics across Three Environments

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2138
Author(s):  
Anna K. Zykova ◽  
Petr V. Pantyukhov ◽  
Elena E. Mastalygina ◽  
Christian Chaverri-Ramos ◽  
Svetlana G. Nikolaeva ◽  
...  

The purpose of this study was to assess the potential for biocomposite films to biodegrade in diverse climatic environments. Biocomposite films based on polyethylene and 30 wt.% of two lignocellulosic fillers (wood flour or flax straw) of different size fractions were prepared and studied. The developed composite films were characterized by satisfactory mechanical properties that allows the use of these materials for various applications. The biodegradability was evaluated in soil across three environments: laboratory conditions, an open field in Russia, and an open field in Costa Rica. All the samples lost weight and tensile strength during biodegradation tests, which was associated with the physicochemical degradation of both the natural filler and the polymer matrix. The spectral density of the band at 1463 cm−1 related to CH2-groups in polyethylene chains decreased in the process of soil burial, which is evidence of polymer chain breakage with formation of CH3 end groups. The degradation rate of most biocomposites after 20 months of the soil assays was greatest in Costa Rica (20.8–30.9%), followed by laboratory conditions (16.0–23.3%), and lowest in Russia (13.2–22.0%). The biocomposites with flax straw were more prone to biodegradation than those with wood flour, which can be explained by the chemical composition of fillers and the shape of filler particles. As the size fraction of filler particles increased, the biodegradation rate increased. Large particles had higher bioavailability than small spherical ones, encapsulated by a polymer. The prepared biocomposites have potential as an ecofriendly replacement for traditional polyolefins, especially in warmer climates.

2011 ◽  
Vol 695 ◽  
pp. 170-173 ◽  
Author(s):  
Voravadee Suchaiya ◽  
Duangdao Aht-Ong

This work focused on the preparation of the biocomposite films of polylactic acid (PLA) reinforced with microcrystalline cellulose (MCC) prepared from agricultural waste, banana stem fiber, and commercial microcrystalline cellulose, Avicel PH 101. Banana stem microcrystalline cellulose (BS MCC) was prepared by three steps, delignification, bleaching, and acid hydrolysis. PLA and two types of MCC were processed using twin screw extruder and fabricated into film by a compression molding. The mechanical and crystalline behaviors of the biocomopsite films were investigated as a function of type and amount of MCC. The tensile strength and Young’s modulus of PLA composites were increased when concentration of MCC increased. Particularly, banana stem (BS MCC) can enhance tensile strength and Young’s modulus of PLA composites than the commercial MCC (Avicel PH 101) because BS MCC had better dispersion in PLA matrix than Avicel PH 101. This result was confirmed by SEM image of fractured surface of PLA composites. In addition, XRD patterns of BS MCC/PLA composites exhibited higher crystalline peak than that of Avicel PH 101/PLA composites


2021 ◽  
Author(s):  
Yamanappagouda Amaregouda ◽  
Kantharaju Kamanna ◽  
Tilak Gasti ◽  
Vijay Kumbar

Abstract Herein, we described novel biogenic preparation of the CuO nanorods and its surface modification with L-alanine amino acid accelerated by microwave irradiation. The effect of surface functionalized CuO nanorods on the polyvinyl alcohol/carboxymethyl cellulose film physico-mechanical properties were investigated through various characterization techniques. The tensile strength was improved from 28.58 ± 0.73 MPa to 43.40 ± 0.93 MPa, UV shielding ability and barrier to the water vapors were highly enhanced when PVA/CMC matrices filled with 8 wt% of CuO-L-alanine. In addition, the prepared films exhibited acceptable overall migration limit and readily undergoes soil burial degradation. Nevertheless, CuO-L-alanine incorporated films showed potent antioxidant activity against DPPH radicals and had high antibacterial activity against Staphylococcus aureus and Escherichia coli, and antifungal activity against Candida albicans and Candida tropicalis. Furthermore, the nanocomposite films showed negligible cytotoxic effect on HEK293 and Caco-2 cell lines. In these contexts, the developed nanocomposite films can be implementing as an active food packaging material.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1119 ◽  
Author(s):  
U. Seeta Uthaya Kumar ◽  
S. N. Abdulmadjid ◽  
N. G. Olaiya ◽  
A. A. Amirul ◽  
S. Rizal ◽  
...  

Neem leaves extract was incorporated into the matrix of seaweed biopolymer, and the seaweed-neem biocomposite films were irradiated with various doses of gamma irradiation (0.5, 1.5, 2.5, 3.5, and 4.5 kGy). The physical, barrier, antimicrobial, and mechanical properties of the films were studied. The incorporation of 5% w/w neem leaves extract into a seaweed-based film, and gamma irradiation dose of 2.5 kGy was most effective for improved properties of the film. The results showed that the interfacial interaction of the seaweed-neem improved with physical changes in colour and opacity. The water solubility, moisture content, and water vapour permeability and biodegradability rate of the film reduced. The contact angle values increased, which was interpreted as improved hydrophobicity. The tensile strength and modulus of the films increased, while the elongation of the composite films decreased compared to the control film. The film’s antimicrobial activities against bacteria were improved. Thus, neem leaves extract in combination with the application of gamma irradiation enhanced the performance properties of the film that has potential as packaging material.


2012 ◽  
Vol 488-489 ◽  
pp. 1016-1020 ◽  
Author(s):  
Sayamon Somsub ◽  
Duangdao Aht-Ong

The objectives of this research were to prepare self-reinforcement biocomposites films from sisal cellulose by solvent casting using NaOH complex solution and to investigate the effect of reinforcement content (i.e., 0, 5, 10, 15, and 20 wt %) in various forms, i.e., sisal microcrystalline cellulose (MCC), commercial MCC, and short sisal fiber, respectively. The sisal MCC was extracted from sisal fiber by means of delignification, bleaching, and acid hydrolysis, respectively. The obtained MCC powder observed by scanning electron microscope (SEM) appeared as short fiber shape with smooth surface having diameter of approximately 10 μm, whereas its length was varied between 67-150 μm. The tensile strength and Young’s modulus of the composite films reinforced with 15 wt % of sisal MCC reached up to 5.16 MPa and 375.25 MPa, respectively. The degradation temperature investigated by thermogravimetric analyzer (TGA) and water absorption values were significantly improved with increasing of reinforcement loading.


2021 ◽  
Vol 2080 (1) ◽  
pp. 012011
Author(s):  
Di Sheng Lai ◽  
Sinar Arzuria Adnan ◽  
Azlin Fazlina Osman ◽  
Ismail Ibrahim ◽  
Hazrul Haq

Abstract Thermoplastic starch (TPS) was studied extensively to replace conventional plastic in packaging application. In this study, granule corn starch was first plasticized with water and glycerol to form TPS films and two different fillers were incorporated with TPS to form hybrid biocomposite films (TPSB). Two different fillers: Microcrystalline cellulose (MC) and Nano bentonite (NB) fixed at 1: 4 ratios in various loading (1wt%-6wt%) were incorporated in TPS to study effect of hybrid fillers on the mechanical properties of TPSB films. The effect of different loading of MC/NB on TPSB films was investigated through the structural, morphological and mechanical testing. Fourier Transform Infrared Spectroscopy (FTIR) shows TPS matrix and hybrid fillers are highly compatible due to hydroxyl bonding and verified through the shifting of spectra band. Scanning Electron Microscope (SEM) showed even distribution of fillers in the matrix of TPS. The TPSB films exhibited significant improvement 40% in elongation at break compared to pure TPS films. In this study, 5wt% is best loading of the hybrid fillers to incorporated in TPSB films as it achieved the highest value of tensile strength (8.52MPa), Young’s Modulus (42.0 MPa) and elongation at break (116.3%). Generally, previous studies showed flexibility of TPS composite films reduced with incorporating filler, however in this study, the flexibility TPSB show significant improvement compared to previous studies and exhibit promising potential in dry food packaging application.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5679
Author(s):  
Jong-Whan Rhim ◽  
Saygin Kuzeci ◽  
Swarup Roy ◽  
Necmettin Akti ◽  
Cumali Tav ◽  
...  

This work reports the effects of free volume on curcumin release in various polymer-based composite films. Curcumin-reinforced biocomposite films were fabricated with natural biopolymers (carrageenan and chitosan) and bioplastics (poly(lactide) (PLA) and poly (butylene adipate-co-terephthalate) (PBAT)) via the solvent casting method. The curcumin release test was performed using an aqueous medium, and it was found that it was released the fastest in the carrageenan film, followed by the chitosan, PLA, and PBAT films, presumably owing to the dissimilarity of the polymer matrix. The free volume of the polymer films was determined using positron annihilation lifetime spectroscopy (PALS) to understand the release phenomena of curcumin. The free volume fraction was varied and reliant on the type of polymer, with the highest in the PBAT-based film followed by the PLA-, chitosan-, and carrageenan-based films. The free volume method helps analyze the release of bioactive compounds in a polymer matrix and may help to achieve a better understanding of the release of bioactive compounds.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2605 ◽  
Author(s):  
A. Rozilah ◽  
C. N. Aiza Jaafar ◽  
S. M. Sapuan ◽  
I. Zainol ◽  
R. A. Ilyas

Antibacterial sugar palm starch biopolymer composite films were developed and derived from renewable sources and inorganic silver nanoparticles (AgNPs) as main ingredients for antibacterial coatings. The composite films were produced by solution casting method and the mechanical and physicochemical properties were determined by tensile test, Fourier Transform Infrared (FTIR) analysis, thermal gravimetric analysis (TGA), antibacterial screening test and field emission scanning electron microscopy (FESEM) images. It was found that mechanical and antibacterial properties of biocomposite films were improved after the addition of AgNPs compared with the film without active metals. The weakness of neat biocomposite films was improved by incorporating inorganic AgNPs as a nanofiller in the films’ matrix to avoid bacterial growth. The results showed that the tensile strength ranged between 8 kPa and 408 kPa and the elasticity modulus was between 5.72 kPa and 9.86 kPa. The addition of AgNPs in FTIR analysis decreased the transmittance value, caused small changes in the chemical structure, caused small differences in the intensity peaks, and produced longer wavelengths. These active films increased the degradation weight and decomposition temperature due to the more heat-stable AgNPs. Meanwhile, the average inhibited areas measured were between 7.66 and 7.83 mm (Escherichia coli), 7.5 and 8.0 mm (Salmonella cholerasuis), and 0.1 and 0.5 mm for Staphylococcus aureus. From the microscopic analysis, it was observed that the average size of all microbes for 1 wt% and 4 wt% AgNPs ranged from 0.57 to 2.90 mm. Overall, 3 wt% AgNP nanofiller was found to be the best composition that fulfilled all the mechanical properties and had better antimicrobial properties. Thus, the development of an organic-inorganic hybrid of antibacterial biopolymer composite films is suitable for antibacterial coatings.


Soil Research ◽  
2016 ◽  
Vol 54 (2) ◽  
pp. 216 ◽  
Author(s):  
D. H. Barragán ◽  
A. M. Pelacho ◽  
Ll. Martin-Closas

Mulches, usually consisting of polyethylene films, are used in agriculture to improve production. The main drawback of using polyethylene is its extremely high stability. Removing it from the field is usually not feasible, and so wastes remain accumulating in the field and pollute the environment. As an alternative, five potentially biodegradable plastic films for mulching (maize thermoplastic starch–copolyester, cereal flour–copolyester, polylactic acid–copolyester, polyhydroxybutyrate, and potato thermoplastic starch–copolyester) were tested to evaluate their degradation in an agricultural soil. Polyethylene film was used as control. A soil burial test was carried out during 6 months under laboratory conditions and film weight loss, chemical changes and soil microbial activity were monitored. Weight loss was fastest for the polyhydroxybutyrate film, followed by potato thermoplastic starch–copolyester and cereal flour–copolyester. Maize thermoplastic starch–copolyester and polylactic acid–copolyester required 5–6 months to disintegrate. Concomitant to the weight loss, chemical changes in the films and an increase in soil microbial activity were noticed. From the disintegration and biodegradation results of the biodegradable tested films, it is concluded that these films are an alternative for avoiding the soil pollution drawbacks of the polyethylene mulching films.


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