scholarly journals Effects of Tensile Stress and Soil Burial on Mechanical and Chemical Degradation Potential of Agricultural Plastic Films

2020 ◽  
Vol 12 (19) ◽  
pp. 7985 ◽  
Author(s):  
Yanan Han ◽  
Min Wei ◽  
Xiaoyan Shi ◽  
Dong Wang ◽  
Xulong Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Tensile Stress ◽  
Film Surface ◽  
Sustainable Land Use ◽  
Chemical Degradation ◽  
Plastic Film ◽  
Biodegradable Film ◽  
Plastic Films ◽  
Soil Burial

Plastic film mulching is widely practiced in arid and semiarid farming systems, but the accumulation of plastic residues in soils can negatively affect soil properties. Therefore, efficient means of plastic film degradation are urgently needed to mitigate its unfriendly environmental impacts for sustainable land use. Here, we characterized the effects of tensile stress (TS) and soil burial (SB) on potential degradation properties of three film types: Polyethylene film (PEF), oxo-biodegradable film (OBDF), and biodegradable film (BDF). Weight loss, mechanical properties, hydrophilicity, functional groups, and crystallinity were recorded after TS and SB treatments. The results indicated that: (1) Weight loss of plastic films was associated with SB, although the extent of weight loss depended on film type and was highest in BDF, (2) application of TS before SB weakened the mechanical properties of the films and increased their hydrophilicity, creating favorable conditions for the settlement of microorganisms on the film surface, (3) PEF treated with TS and SB had higher functional group indices and lower crystallinity. Our results highlighted that the combination of TS and SB has the potential to accelerate plastic film degradation.

scholarly journals Synthesis, Characterization, and Biodegradation Studies of Poly(1,4-cyclohexanedimethylene-adipate-carbonate)s

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ajay S. Chandure ◽  
Ganesh S. Bhusari ◽  
Suresh S. Umare
Keyword(s):  
Weight Loss ◽  
Enzymatic Degradation ◽  
Hydrolytic Degradation ◽  
Phosphate Buffer Solution ◽  
Film Surface ◽  
Solution Viscosity ◽  
Buffer Solution ◽  
Sem Images ◽  
Titanium Butoxide ◽  
Soil Burial

Aliphatic/alicyclic poly(1,4-cyclohexanedimethylene-adipate-carbonate)s (PCACs) were synthesized by a transesterification from 1,4-cyclohexamethylendimethanol (1,4-CHDM), adipic acid (AA), diethyl carbonate (DEC), and titanium butoxide Ti(OBu)4 as a transesterification catalyst. The synthesized PCACs were characterized by the Fourier transform infrared (FTIR), X-ray diffraction analysis (XRD), solubility, solution viscosity, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscope (SEM) for their structural, physical, thermal, and morphological investigation. The structure of synthesized PCACs was confirmed by FTIR. All TGA curves of PCACs shows 10% weight loss above 270°C, and they reveal good thermal stability. Biodegradability of PCACs was investigated by hydrolytic degradation at (pH 7.2 and 11.5), enzymatic degradation using Rhizopus delemar lips at 37°C in phosphate buffer solution (PBS), and soil burial degradation at 30°C. The hydrolytic degradation shows the greater rate of weight loss in PBS at pH-11.5 than pH-7.2. The hydrolytic and soil burial degradation shows faster rate of weight loss as compared to enzymatic degradation. Biodegradation rate of PCACs follows the order: PCAC-20 > PCAC-40 > PCAC-60. SEM images show that degradation occurred all over the film surface, creating holes and cracks. These biodegradable PCACs may be able to replace conventional polymer in the fabrication of packaging film in near future.

scholarly journals PENGARUH WAKTU SIMPAN FILM PLASTIK BIODEGRADASI DARI PATI KULIT SINGKONG TERHADAP SIFAT MEKANIKALNYA

2013 ◽  
Vol 2 (2) ◽  
Author(s):  
Fauzi Akbar ◽  
Zulisma Anita ◽  
Hamidah Harahap
Keyword(s):  
Mechanical Properties ◽  
Storage Time ◽  
Thin Sheet ◽  
Biodegradable Plastics ◽  
Plastic Film ◽  
Elongation At Break ◽  
Plastic Films ◽  
Plasticizer Migration ◽  
Cassava Peel ◽  
Main Material

Biodegradable plastics are plastics that will decompose in nature with the help of microorganisms. The use of starch as the main material of plastic manufacturing has great potential because in Indonesia there are different starch crops. To obtain bioplastics, starch is added to the plasticizer glycerol, in order to obtain a more flexible plastic and elastic. This study reviews the use of cassava starch and glycerol skin as a base for the manufacture of biodegradable plastics. The purpose of this research is to know the effect of storage time on the mechanical properties of plastic film biodegradation of starch cassava peel. The results obtained in the form of a thin sheet plastic film that have been tested mechanical properties such as tensile strength, elongation at break, and elasticity. Mechanical properties of plastic films will decrease every week due to the absorption of moisture and plasticizer migration occurs in a matrix of plastic films for storage.

scholarly journals PEMANFAATAN LIMBAH PLASTIK MENJADI KEMASAN RAMAH LINGKUNGAN SERTA UJI BIODEGRADASINYA

2018 ◽  
Vol 1 (2) ◽  
pp. 33-38
Author(s):  
Asiska Permata Dewi ◽  
Yulia Yesti
Keyword(s):  
Test Method ◽  
Plastic Film ◽  
Solvent Casting ◽  
Average Thickness ◽  
Biodegradation Rate ◽  
Soil Burial Test ◽  
Plastic Films ◽  
Soil Burial ◽  
Biodegradable Packaging ◽  
Rate Profile

Manufacturing of prototype of plastics film for a biodegradable packaging from a mixture of polymer synthetic polystyrene (PS) and polycaprolactone (PCL) has been carried out. Plastics film containing of PS/PCL created by blending techniques followed by solvent casting, the ratios were 100/0, 95/5, 90/10 and 85/15. The resulting of plastic film is a clear sheet with an average thickness of 0.03 cm. The biodegradation rate profile was observed by soil burial test method to see the weight reduction of the plastic films tested for a certain period of time. The results showed that the biodegradation rate profile increased with the addition of PCL with the t50% in the 100/0, 95/5, 90/10 and 85/15 ratios respectively being 352.33; 91.19; 71.97 and 59.85 weeks, and t95% in the 100/0, 95/5, 90/10 and 85/15 ratios were respectively 677.01; 177.32; 139.43 and 115.79 weeks. Furthermore, the number of microbes present in each gram of soil is 1.83 x 105.

scholarly journals Production of Starch-Based Bioplastic from Durio zibethinus Murr Seed Using Glycerol as Plasticizer

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Nanda Raudhatil Jannah ◽  
Novesar Jamarun ◽  
Yulia Eka Putri
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Tensile Strength ◽  
Fourier Transform ◽  
Functional Group ◽  
Soil Burial Test ◽  
Soil Burial ◽  
Durio Zibethinus ◽  
The Fourier Transform ◽  
Scanning Electron

Bioplastics are bio-based plastics from natural resources, made to replace conventional plastics. The utilization of biopolymers in bioplastics provide a faster degradation compared to petroleum-based plastics. Starch-based bioplastic from mixing Durio zibethinus Murr starch and glycerol as plasticizer have been conducted. In this research, the concentration of glycerol has been varied to study the effect on starch-based bioplastics mechanical properties. The tensile strength for Durio zibethinus Murr starch-based bioplastic with 20% glycerol was 50.28 MPa with 13.3% elongation. The functional group found on the Fourier transform infrared spectroscopy (FTIR) spectra indicated the presence of O-H stretch, C-H stretch, C=O stretch, and C-O stretch which stated the formation of bioplastic. The image results gained from scanning electron microscope (SEM) showed that the morphology surface of bioplastic was less homogenous and rough. The soil burial test for biodegradability showed Durio zibethinus Murr starch-based bioplastic achieved 38.9% weight loss in a 5-day observation.

scholarly journals A novel, thermotolerant, extracellular PHB depolymerase producer Paenibacillus alvei PHB28 for bioremediation of biodegradable plastics

2018 ◽  
Vol 44 (3) ◽  
pp. 344-353
Author(s):  
Kulsoom Bano ◽  
Mohammed Kuddus ◽  
Mohd Rehan Zaheer ◽  
Roohi
Keyword(s):  
Weight Loss ◽  
Biodegradable Plastics ◽  
The Novel ◽  
Plastic Pollution ◽  
Plastic Films ◽  
Phb Depolymerase ◽  
Soil Burial ◽  
Nutrient Supplements ◽  
Paenibacillus Alvei ◽  
Extracellular Phb Depolymerase

Abstract Background Poly-β-hydroxybutyrate (PHB) is the most important and versatile class of biodegradable polymers used successfully in the medical, agricultural and industrial field. Idea is to find the novel isolate for degradation of biodegradable plastics that can enhance the bioremediation. Materials and methods Thirty-one PHB and PHB depolymerase enzyme producing isolates out of 80 mesophilic bacteria from Lucknow region were further screened for PHB degradation capability by secreting extracellular PHB depolymerase enzyme in minimal salt media supplemented with PHB (0.15%). Various biodegradable plastic films were tested by soil burial method for weight loss determination. Result 37.3% weight loss has been observed in PHB films when buried under the soil for 45 days in the presence of a novel PHB degrader identified as Paenibacillus alvei PHB28 by 16S rRNA sequencing (GenBank accession number KX886342). These Gram-negative, spore-forming, thermotolerant bacteria produce maximum PHB depolymerase (5.03 U/mL) at 45°C, pH 8.0, with 0.15% substrate concentration when incubated for 96 h with starch (0.1%) and yeast extract (0.01%) as an additional nutrient supplements. Conclusion To the best of our knowledge this is the first report of PHB depolymerase production by P. alvei PHB28 which may contribute successfully to combat plastic pollution and to sustain the green environment.

Water saving technology of cotton sowing

2019 ◽  
Vol 1 (4) ◽  
pp. 16-22
Author(s):  
Ongarbay P. Auezov ◽  
Bazarbay K. Utepbergenov ◽  
Bakhitbay N. Ramazanov
Keyword(s):  
Mechanical Properties ◽  
Water Scarcity ◽  
Physical And Mechanical Properties ◽  
Water Saving ◽  
Plastic Film ◽  
Properties Of Soil

This article presents the results of a technology of placing a plastic film in the space between cotton rows. We have studied physical and mechanical properties of soil before placing the film. We have proved that the plastic film in the spaces between the cotton rows retains moisture in the soil much longer and it is possible to obtain up to 22 kg/ha of raw cotton in the condition of water scarcity in the Karakalpakstan.

scholarly journals Mesoscale Modelling of Concretes Subjected to Triaxial Loadings: Mechanical Properties and Fracture Behaviour

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1099
Author(s):  
Qingqing Chen ◽  
Yuhang Zhang ◽  
Tingting Zhao ◽  
Zhiyong Wang ◽  
Zhihua Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Stress ◽  
Failure Criterion ◽  
Mesoscale Model ◽  
Fracture Behaviour ◽  
Descent Method ◽  
Triaxial Stress ◽  
Gradient Descent Method ◽  
Stress States ◽  
Shear Failures

The mechanical properties and fracture behaviour of concretes under different triaxial stress states were investigated based on a 3D mesoscale model. The quasistatic triaxial loadings, namely, compression–compression–compression (C–C–C), compression–tension–tension (C–T–T) and compression–compression–tension (C–C–T), were simulated using an implicit solver. The mesoscopic modelling with good robustness gave reliable and detailed damage evolution processes under different triaxial stress states. The lateral tensile stress significantly influenced the multiaxial mechanical behaviour of the concretes, accelerating the concrete failure. With low lateral pressures or tensile stress, axial cleavage was the main failure mode of the specimens. Furthermore, the concretes presented shear failures under medium lateral pressures. The concretes experienced a transition from brittle fracture to plastic failure under high lateral pressures. The Ottosen parameters were modified by the gradient descent method and then the failure criterion of the concretes in the principal stress space was given. The failure criterion could describe the strength characteristics of concrete materials well by being fitted with experimental data under different triaxial stress states.

On the use of Ozawa/Flynn/Wall method to determine aging activation energy for elastomers

2021 ◽  
pp. 009524432110203
Author(s):  
Sudhir Bafna
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Weight Loss ◽  
Oxygen Consumption ◽  
Dwell Time ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Degradation Mechanism ◽  
Kinetics Of ◽  
Wall Method

It is often necessary to assess the effect of aging at room temperature over years/decades for hardware containing elastomeric components such as oring seals or shock isolators. In order to determine this effect, accelerated oven aging at elevated temperatures is pursued. When doing so, it is vital that the degradation mechanism still be representative of that prevalent at room temperature. This places an upper limit on the elevated oven temperature, which in turn, increases the dwell time in the oven. As a result, the oven dwell time can run into months, if not years, something that is not realistically feasible due to resource/schedule constraints in industry. Measuring activation energy (Ea) of elastomer aging by test methods such as tensile strength or elongation, compression set, modulus, oxygen consumption, etc. is expensive and time consuming. Use of kinetics of weight loss by ThermoGravimetric Analysis (TGA) using the Ozawa/Flynn/Wall method per ASTM E1641 is an attractive option (especially due to the availability of commercial instrumentation with software to make the required measurements and calculations) and is widely used. There is no fundamental scientific reason why the kinetics of weight loss at elevated temperatures should correlate to the kinetics of loss of mechanical properties over years/decades at room temperature. Ea obtained by high temperature weight loss is almost always significantly higher than that obtained by measurements of mechanical properties or oxygen consumption over extended periods at much lower temperatures. In this paper, data on five different elastomer types (butyl, nitrile, EPDM, polychloroprene and fluorocarbon) are presented to prove that point. Thus, use of Ea determined by weight loss by TGA tends to give unrealistically high values, which in turn, will lead to incorrectly high predictions of storage life at room temperature.

scholarly journals Influence of artificial aging: mechanical and physicochemical properties of dental composites under static and dynamic compression

2021 ◽  
Author(s):  
D. C. Gornig ◽  
R. Maletz ◽  
P. Ottl ◽  
M. Warkentin
Keyword(s):  
Mechanical Properties ◽  
Water Sorption ◽  
Artificial Aging ◽  
Filler Content ◽  
Dynamic Compression ◽  
The Other ◽  
Chemical Degradation ◽  
Dental Composites ◽  
Compression Tests ◽  
Acid Ph

Abstract Objective The aim of the study was to evaluate the influence of filler content, degradation media and time on the mechanical properties of different dental composites after in vitro aging. Materials and Methods Specimens (1 mm3) of three commercially available composites (GrandioSO®, Arabesk Top®, Arabesk Flow®) with respect to their filler content were stored in artificial aging media: artificial saliva, ethanol (60%), lactic acid (pH 5) and citric acid (pH 5). Parameters (Vickers microhardness, compressive strength, elastic modulus, water sorption and solubility) were determined in their initial state (control group, n = 3 for microhardness, n = 5 for the other parameters) and after 14, 30, 90 and 180 days (n = 3 for microhardness, n = 5 for the other parameters for each composite group, time point and media). Specimens were also characterized with dynamic-mechanical-thermal analysis (compression tests, F =  ± 7 N; f = 0.5 Hz, 1 Hz and 3.3 Hz; t = 0–170 °C). Results Incorporation of fillers with more than 80 w% leads to significantly better mechanical properties under static and dynamic compression tests and a better water sorption behavior, even after chemical degradation. The influence of degradation media and time is of subordinate importance for chemical degradation. Conclusion Although the investigated composites have a similar matrix, they showed different degradation behavior. Since dentine and enamel occur only in small layer thickness, a test specimen geometry with very small dimensions is recommended for direct comparison. Moreover, the use of compression tests to determine the mechanical parameters for the development of structure-compatible and functionally adapted composites makes sense as an additional standard. Clinical relevance Preferential use of highly filled composites for occlusal fillings is recommended.

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