scholarly journals Preparation of Organic Crystal Seed and Its Application in Improving the Functional Period of Biodegradable Agricultural Film

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 826
Author(s):  
Runmeng Qiao ◽  
Xin Wang ◽  
Guangjiong Qin ◽  
Qi Liu ◽  
Jialei Liu ◽  
...  

White pollution caused by agricultural films has recently attracted great attention. In some areas, the content of micro plastic in the soil has reached 30 kg/ha. The most effective way to solve this problem is to replace traditional polyethylene agricultural films with degradable agricultural films. The consistency between the degradation rate and the crop growth period has become the biggest obstacle for the wide application of such novel agricultural films. In this paper, crystallinity regulation is used to adjust the functional period of degradable agricultural films. In addition, an organic nucleating agent of polyethylenimine (PEI) is selected by doping it to poly(butylene adipate-co-terephthalate) (PBAT) polymers using a double-screw extruder. The PBAT doped with 1 wt% PEI films revealed a significant increase in mechanical properties, water holding capacity, and crystallinity compared with the pure PBAT film. There was a 31.9% increase in tensile strength, a 30.5% increase in elongation at break, a 29.6% increase in tear resistance, a 30.9% decrease in water vapor permeability, and a 3.1% increase in crystallinity. Furthermore, the induction period of PBAT doped with 1 wt% PEI under photoaging (without soil) was about 160 h longer than PBAT film, and the experienced biodegradation in soil (without light) was 1 week longer than PBAT film. Experimental results exhibited that the change of degradation degree was linearly proportional to the degree of crystallinity. This study proposes a convenient, low-cost, and effective method to adjust the crystallinity and change the degradation rate.

e-Polymers ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 038-046
Author(s):  
Xu Yan ◽  
Wanru Zhou ◽  
Xiaojun Ma ◽  
Binqing Sun

Abstract In this study, a poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) modified with nano-montmorillonite biocomposite (MMT/PHBH) was fabricated by solution-casting method. The results showed that the addition of MMT increased the crystallinity and the number of spherulites, which indicated that MMT was an effective nucleating agent for PHBH. The maximum decomposition peak of the biocomposites moved to a high temperature and residue presented an increasing trend. The biocomposites showed the best thermal stability at 1 wt% MMT. Compared with PHBH, 182.5% and 111.2% improvement in elastic modulus and tensile strength were obtained, respectively. Moreover, the oxygen permeability coefficient and the water vapor permeability of MMT/PHBH biocomposites decreased by 43.9% and 6.9%, respectively. It was also found that the simultaneous enhancements on the crystallizing, thermal stability, mechanical, and barrier properties of biocomposites were mainly caused by the formation of intercalated structure between PHBH and MMT.


Author(s):  
Grégoire David ◽  
Laurent Heux ◽  
Stéphanie Pradeau ◽  
Nathalie Gontard ◽  
Hélène Angellier-Coussy

Abstract This paper aims at investigating the potential of vine shoots (ViSh) upcycling as fillers in novel poly(3-hydroxybutyrate-3-hydroxyvalerate) (PHBV) based biocomposites. ViSh particles of around 50 µm (apparent median diameter) were obtained combining dry grinding processes, and mixed with PHBV using melt extrusion. Thermal stability and elongation at break of biocomposites were reduced with increasing contents of ViSh particles (10, 20 and 30 wt%), while Young’s modulus and water vapor permeability were increased. It was shown that a surface gas-phase esterification allowed to significantly increase the hydrophobicity of ViSh particles (increase of water contact angles from 59° to 114°), leading to a reduction of 27% in the water vapor permeability of the biocomposite filled with 30 wt% of ViSh. The overall mechanical performance was not impacted by gas-phase esterification, demonstrating that the interfacial adhesion between the virgin ViSh particles and the PHBV matrix was already good and that such filler surface treatment was not required in that case. It was concluded that ViSh particles can be interestingly used as low cost fillers in PHBV-based biocomposites to decrease the overall cost of materials.


2019 ◽  
Vol 2 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Lan Yao ◽  
Lantao Wu ◽  
Hao Wu ◽  
Joseph. H. Koo ◽  
Mourad Krifa

AbstractIn current thermal protective clothing systems, maximizing the personal protection performance against fire and heat is in great demand. Additionally, minimizing the manufacturing cost by using low-cost materials is also a critical factor. In previous studies [1–3], a new type of low-cost inherently flame resistant (FR) non-drip Polyamide 6 (PA6) nanocomposite fiber was developed. In this paper, this FR non-drip PA6 fiber was tested in blends with two commercially available inherently FR fibers to form FR nonwoven fabrics. Different formulations of varying blending ratios were processed into nonwoven fabrics. The fiber morphology was observed by Scanning Electron Microscopy (SEM). The fabric flammability and combustion properties were characterized using a Microscale Combustion Calorimeter (MCC), and a vertical flame tester, as well as Thermogravimetric Analysis (TGA). Tensile tests were conducted to characterize mechanical properties of these FR nonwoven fabrics. The water vapor permeability test was also performed to measure the wearability of the fabric. Results of several nonwoven blends were compared to find the one with optimum blend ratio which has the potential to be used as low-cost thermal protective fabric.


2018 ◽  
Vol 930 ◽  
pp. 270-275 ◽  
Author(s):  
Victor Rafael Leal Oliveira ◽  
M.K.S. Monteiro ◽  
F.K.G. Santos ◽  
R.H.L. Leite ◽  
E.M.M. Aroucha

Coating technologies with biopolymeric films of low cost and high efficiency are effective in maintaining the chemical and sensory characteristics and shelf-life extension of several fruits.Films of cassava starch/glycerol were synthesized at different temperature and time conditions (25oC / 60h, 40oC / 5h, 60oC / 3h and 80oC / 2h) in order to decrease the drying time of the filmogenic solutions.SEM analysis (scanning electron microscopy), WVP (water vapor permeability), wettability and mechanical properties were evaluated in order to identify morphological and structural changes in the polymeric matrix in different conditions.Changes in temperature and drying time significantly reduced the roughness and affected the barrier characteristics, effectively improving tensile strength. A reduction of more than 90% in the drying time was identified.


Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2399
Author(s):  
Bich Nam Jung ◽  
Hyun Wook Jung ◽  
DongHo Kang ◽  
Gi Hong Kim ◽  
Jin Kie Shim

Since the plastic-based multilayer films applied to food packaging are not recyclable, it is necessary to develop easily recyclable single materials. Herein, polypropylene (PP)-based cellulose nanofiber (CNF)/nanoclay nanocomposites were prepared by melt-mixing using a fixed CNF content of 1 wt %, while the nanoclay content varied from 1 to 5 wt %. The optimum nanoclay content in the PP matrix was found to be 3 wt % (PCN3), while they exhibited synergistic effects as a nucleating agent. PCN3 exhibited the best mechanical properties, and the tensile and flexural moduli were improved by 51% and 26%, respectively, compared to PP. In addition, the oxygen permeability was reduced by 28%, while maintaining the excellent water vapor permeability of PP. The improvement in the mechanical and barrier properties of PP through the production of PP/CNF/nanoclay hybrid nanocomposites suggested their possible application in the field of food packaging.


2020 ◽  
Vol 1012 ◽  
pp. 57-61
Author(s):  
Hortência Nathânia Silva Câmara ◽  
Francisco Leonardo Gomes de Menezes ◽  
Ricardo Henrique de Lima Leite ◽  
Edna Maria Mendes Aroucha ◽  
Francisco Klebson Gomes dos Santos

The use of natural polymeric materials has been growing notably in order to replace packaging from non-renewable sources. In this sense, cassava starch is a very promising natural polymer for this purpose due to its ease of production, the low cost, besides being biodegradable. However, cassava starch biofilms when dried have a brittle character requiring the addition of a plasticizer. Thus, biofilms were synthesized based on cassava starch (3%) with different percentages of glycerol (5%, 10%, 20%, 40% and 50%) to evaluate changes in physic-chemical and mechanical properties. The results indicate that the increase in percentage of glycerol contributed directly to the increase of water vapor permeability while decreases the contact angle and modulus of elasticity of cassava starch films.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8268-8290
Author(s):  
P. R. D. Weerasooriya ◽  
H. P. S. Abdul Khalil ◽  
Noor Haida Mohd Kaus ◽  
Md. Sohrab Hossain ◽  
Salim Hiziroglu ◽  
...  

There is increasing interest in regenerated cellulose (RC) films for advanced manufacturing applications using natural polymers and renewable materials. In this study, RC films were isolated via solution casting process using microcrystalline cellulose (MCC) and the ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl). Initially, MCC was synthesized from oil palm empty fruit bunch using total chlorine-free (TCF) pulping and acid hydrolysis. Effects of MCC on the structures and physicochemical properties of the isolated RC films were determined for 4 wt%, 6.5 wt%, and 9 wt% of MCC at 80 °C. Several analytical methods were employed to evaluate degree of crystallinity, chemical stability, mechanical properties, morphology, opacity, water vapor permeability, and thermal stability of the RC films. The results showed that the addition of 6.5 wt% of MCC yielded the greatest tensile strength. Compared with the RC films with 6.5 wt% of MCC, thermal stability and water vapor permeability slightly increased when the MCC content was 9 wt%. According to the analytic hierarchy process (AHP), 6.5 wt% of MCC was the optimum MCC concentration to mix with [BMIM]Cl to manufacture RC films for packaging applications, while 9 wt% of MCC was ideal for photocatalytic and electrically conductive thin film applications.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jinshu Liu ◽  
Xiaoyan Ma ◽  
Wenzhao Shi ◽  
Jianwei Xing ◽  
Chaoqun Ma ◽  
...  

Abstract Baicalin, an active flavonoid ingredient of Scutellaria baicalensis Georgi, was extracted by heat reflux extraction and showed the same significance UV absorption property with standard baicalin. Active films were prepared from polyvinyl alcohol (PVA) containing baicalin extract by casting method. The effect of baicalin extracts on the UV-blocking, optical, antioxidant property, water vapor permeability, swelling and mechanical properties of the films were studied. UV–vis transmittance spectra showed that PVA films incorporated with baicalin extract blocked ultraviolet light range from 280–400 nm even with low concentration of baicalin (0.5 wt%) and maintain the high transparency in visible spectrum. The outstanding UV-blocking properties of PVA films incorporated with baicalin extract were also confirmed by Rhodamine B degradation. Baicalin conferred antioxidant properties to PVA films as determined by DPPH radical scavenging activity. Due to the interaction between hydroxy groups of baicalin and PVA molecule, water vapor permeability, swelling and elongation at break of the films were decreased accompanied with the increasing in tensile strength and Young’s modulus. FTIR reveal that the interaction between PVA molecules was significant changed by the introduction of baicalin. These results suggest that PVA film incorporated with baicalin extract can be used for the development of functional protective film.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 602
Author(s):  
Carmen Rodica Pop ◽  
Teodora Emilia Coldea ◽  
Liana Claudia Salanţă ◽  
Alina Lăcrămioara Nistor ◽  
Andrei Borşa ◽  
...  

Kefiran is an exopolysaccharide classified as a heteropolysaccharide comprising glucose and galactose in equimolar quantities, and it is classified as a water-soluble glucogalactan. This work aimed to investigate the effect of different extraction conditions of kefiran on the structural and physical properties of the edible films obtained. Fourier-transform infrared spectroscopy and scanning electron microscopy were performed, together with a determinations of moisture content, solubility, water vapor permeability and degree of swelling. The kefiran films presented values of the water vapor permeability between 0.93 and 4.38 × 10−11 g/m.s.Pa. These results can be attributed to the development of a more compact structure, where glycerol had no power to increase the free volume and the water vapor diffusion through their structure. The possible conformational changes in the kefiran film structure, due to the interspersing of the plasticizers and water molecules that they absorb, could be the reason for producing flexible kefiran films in the case of using glycerol as a plasticizer at 7.5% w/w. Moreover, it was observed that the extraction conditions are a significant factor in the properties of these films and their food technology applications.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 769
Author(s):  
Vlad Mihalca ◽  
Andreea Diana Kerezsi ◽  
Achim Weber ◽  
Carmen Gruber-Traub ◽  
Jürgen Schmucker ◽  
...  

Food packaging is an area of interest not just for food producers or food marketing, but also for consumers who are more and more aware about the fact that food packaging has a great impact on food product quality and on the environment. The most used materials for the packaging of food are plastic, glass, metal, and paper. Still, over time edible films have become widely used for a variety of different products and different food categories such as meat products, vegetables, or dairy products. For example, proteins are excellent materials used for obtaining edible or non-edible coatings and films. The scope of this review is to overview the literature on protein utilization in food packages and edible packages, their functionalization, antioxidant, antimicrobial and antifungal activities, and economic perspectives. Different vegetable (corn, soy, mung bean, pea, grass pea, wild and Pasankalla quinoa, bitter vetch) and animal (whey, casein, keratin, collagen, gelatin, surimi, egg white) protein sources are discussed. Mechanical properties, thickness, moisture content, water vapor permeability, sensorial properties, and suitability for the environment also have a significant impact on protein-based packages utilization.


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