Nanoarchitectonics Composites of Thermoplastic Starch and Montmorillonite Modified with Low Molecular Weight Polylactic Acid

2020 ◽  
Vol 20 (5) ◽  
pp. 2955-2963
Author(s):  
Peixian Li ◽  
Huimin Guo ◽  
Kaixiong Yang ◽  
Xiaoyan Yu ◽  
Xiongwei Qu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Strength ◽  
Polylactic Acid ◽  
Composite Films ◽  
Thermoplastic Starch ◽  
Nanocomposite Films ◽  
Low Molecular Weight ◽  
Elongation At Break ◽  
Starch Films

Nano montmorillonite (MMT) was modified by low molecular weight polylactic acid (PLA), then, the PLA modified MMT and raw MMT were added into thermoplastic starch (TPS) to prepare biodegradable nanocomposite films, respectively. For both nanocomposite films with raw MMT and modified MMT, the Tmax of degradation was enhanced and the mechanical properties were improved. The composite films containing 4 wt.% MMT displayed tensile strength of 5.06 MPa, approximately 1.4 times of that for the pure TPS films. The tensile strength of composite films containing 4 wt.% modified MMT is 6.74 MPa approximately 2 times of those for pure starch films. On the other hand, the composite film containing 4 wt.% modified MMT displayed elongation at break as high as 34.25%, which is 1.3 times of that of the pure starch film, while the composite films containing raw MMT had reduced elongation at break. This study showed that the MMT modified with PLA could significantly enhance the mechanical properties of TPS, and provides a new method to prepare fully biodegradable starch-based nanocomposites.

Synthesis of Cyclic Polysulfides and their Properties as Curing Agents

2004 ◽  
Vol 77 (2) ◽  
pp. 380-390
Author(s):  
Wonmun Choi ◽  
Tomoyuki Matsumura
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Strength ◽  
High Molecular Weight ◽  
Mass Spectra ◽  
Elongation At Break ◽  
Molecular Weights ◽  
Aging Properties ◽  
Curing Agents ◽  
Polysulfide Polymer

Abstract The reactions of dichloroalkanes and sodium tetra-sulfide (Na2S4) were carried out in a mixture of water and toluene to produce corresponding cyclic polysulfides and polysulfide polymer. The low molecular weights of cyclic sulfides were obtained by the reaction at 90 °C, while the high molecular weight of polysulfide polymer was obtained by the reaction at 50 °C. GPC chromatograms and Mass spectra revealed that the structures of cyclic polysulfide were 1:1, 2:2, and 3:3 adducts of dichloroalkane and sodium tetra-sulfide. The mechanical properties of vulcanized NR at 148 °C with cyclic sulfides were similar to that with sulfur. However, both tensile strength and elongation at break of vulcanized NR at 170 °C with cyclic sulfides are much higher than that with sulfur. The aging properties of vulcanized NR at 148 °C or 170 °C with cyclic polysulfides indicate better stability.

scholarly journals Monitoring the degradation of partly decomposable plastic foils

2014 ◽  
Vol 6 (1) ◽  
pp. 39-44
Author(s):  
Gabriella Rétháti ◽  
Krisztina Pogácsás ◽  
Tamás Heffner ◽  
Barbara Simon ◽  
Imre Czinkota ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Molecular Mass ◽  
Structural Changes ◽  
Thermoplastic Starch ◽  
Medium Density ◽  
Insulating Layer ◽  
Elongation At Break ◽  
One Year ◽  
The One

Abstract We have monitored the behaviour of different polyethylene foils including virgin medium density polyethylene (MDPE), MDPE containing pro-oxydative additives (238, 242) and MDPE with pro-oxydative additives and thermoplastic starch (297) in the soil for a period of one year. A foil based on a blend of polyester and polylactic acid (BASF Ecovio) served as degradable control. The experiment was carried out by weekly measurements of conductivity and capacity of the soil, since the setup was analogous to a condenser, of which the insulating layer was the foil itself. The twelve replications allowed monthly sampling; the specimen taken out from the soil each month were tested visually for thickness, mechanical properties, morphological and structural changes, and molecular mass. Based on the obtained capacity values, we found that among the polyethylene foils, the one that contained thermoplastic starch extenuated the most. This foil had the greatest decrease in tensile strength and elongation at break due to the presence of thermoplastic starch. The starch can completely degrade in the soil; thus, the foil had cracks and pores. The polyethylene foils that contained pro-oxydant additives showed smaller external change compared to the virgin foil, since there was no available UV radiation and oxygen for their degradation. The smallest change occurred in the virgin polyethylene foil. Among the five examined samples, the commercially available BASF foil showed the largest extenuation and external change, and it deteriorated the most in the soil.

scholarly journals Bio-Based Thermoplastic Starch Composites Reinforced by Dialdehyde Lignocellulose

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3236
Author(s):  
Peng Yin ◽  
Wen Zhou ◽  
Xin Zhang ◽  
Bin Guo ◽  
Panxin Li
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Water Resistance ◽  
Thermoplastic Starch ◽  
Contact Angles ◽  
Sem Images ◽  
Elongation At Break ◽  
Injection Process ◽  
Oxidation Damage

In order to improve the mechanical properties and water resistance of thermoplastic starch (TPS), a novel reinforcement of dialdehyde lignocellulose (DLC) was prepared via the oxidation of lignocellulose (LC) using sodium periodate. Then, the DLC-reinforced TPS composites were prepared by an extrusion and injection process using glycerol as a plasticizer. The DLC and LC were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the effects of DLC content on the properties of the DLC/TPS composites were investigated via the evaluation of SEM images, mechanical properties, thermal stability, and contact angles. XRD showed that the crystallinity of the DLC decreased due to oxidation damage to the LC. SEM showed good dispersion of the DLC in the continuous TPS phase at low amounts of DLC, which related to good mechanical properties. The tensile strength of the DLC/TPS composite reached a maximum at a DLC content of 3 wt.%, while the elongation at break of the DLC/TPS composites increased with increasing DLC content. The DLC/TPS composites had better thermal stability than the neat TPS. As the DLC content increased, the water resistance first increased, then decreased. The highest tensile strength and elongation at break reached 5.26 MPa and 111.25%, respectively, and the highest contact angle was about 90.7°.

Effect of Co60γ Ray Irradiation on Thermoplastic Corn Starch Plastic

2013 ◽  
Vol 772 ◽  
pp. 34-37
Author(s):  
Hao Tang ◽  
Hai Tian Jiang ◽  
Bin Guo ◽  
Pan Xin Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Corn Starch ◽  
Irradiation Time ◽  
Thermoplastic Starch ◽  
Endothermic Peak ◽  
Macromolecular Structure ◽  
Thermal And Mechanical Properties ◽  
Elongation At Break ◽  
Γ Ray

Corn starch was irradiated by 60Coγ ray, and then the thermoplastic starch plastic (TPS) was prepared by adding glycerol. Microstructure, thermal and mechanical properties of the corn starch and starch plastic were studied in details by FTIR, DSC and SEM. Results showed that the starch macromolecular structure was damaged by irradiation, and with increased irradiation time, the temperature of melt endothermic peak and tensile strength decreased, elongation at break increases for starch plastic, the thermoplastic property of starch was enhanced obviously.

Preparation and Properties of Biocomposite Film with Gelatin and Poly(Vinyl Alcohol)

2011 ◽  
Vol 287-290 ◽  
pp. 302-305
Author(s):  
Xi Ping Gao ◽  
Ke Yong Tang ◽  
Yu Qing Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Optical Properties ◽  
Vinyl Alcohol ◽  
Composite Films ◽  
Poly Vinyl Alcohol ◽  
Elongation At Break ◽  
Biocomposite Film

The mechanical properties, swelling, solubility, and optical properties of composite films with poly(vinyl alcohol) (PVA) and gelatin were studied. With increasing the PVA content in the composite films, the tensile strength (TS) and elongation at break (EB) of the films increase. The swelling and solubility are different with different gelatin/PVA ratios, with the lowest at 1:5.

scholarly journals Mechanical Properties of Thermoplastic Starch Biocomposite Films with Hybrid Fillers

2021 ◽  
Vol 2080 (1) ◽  
pp. 012011
Author(s):  
Di Sheng Lai ◽  
Sinar Arzuria Adnan ◽  
Azlin Fazlina Osman ◽  
Ismail Ibrahim ◽  
Hazrul Haq
Keyword(s):  
Mechanical Properties ◽  
Food Packaging ◽  
Corn Starch ◽  
Composite Films ◽  
Thermoplastic Starch ◽  
Elongation At Break ◽  
Biocomposite Films ◽  
Hybrid Fillers ◽  
The Matrix ◽  
Dry Food

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.

scholarly journals Flexible Thermoplastic Starch Films Functionalized With Copper Particles for Packaging of Food Products

2020 ◽  
Author(s):  
Olivia López ◽  
María E. Villanueva ◽  
Guillermo J. Copello ◽  
Marcelo A Villar
Keyword(s):  
Inhibitory Concentration ◽  
Corn Starch ◽  
Composite Films ◽  
Thermoplastic Starch ◽  
Biodegradable Films ◽  
Melt Mixing ◽  
Elongation At Break ◽  
Copper Particles ◽  
Starch Films ◽  
Fresh Products

Abstract Biodegradable films based on thermoplastic corn starch (TPS) and copper particles with antimicrobial capacity were developed. Copper nanoparticles (Cu) and silica coated copper microparticles (Si-Cu) in the range of 0.25 to 5 % were used. Composite films were obtained by melt-mixing and subsequent thermo-compression. Particles distribution within TPS matrix and the presence of some pores and cracks, induced by Si-Cu particles, was evaluated by SEM. The presence of both fillers gave to composite films a brown pigmentation and decreased their transparency; these effects were more pronounced at higher particles concentrations. Regarding mechanical properties, copper particles at 1 and 5 % acted as reinforcing agents increasing the maximum tensile strength but their presence lead to a decrease in elongation at break, affecting films ductility. Composites inhibited the growth of Gram+ and Gram- bacteria, demonstrating their antimicrobial capacity. Copper effectively migrated to a simulant of aqueous foods and naked particles concentration in the simulant medium resulted higher than the minimum inhibitory concentration for bacteria. The characteristics and properties of developed composite films make them an interesting material for food primary packaging, mainly for meat fresh products.

scholarly journals Flexible Thermoplastic Starch Films Functionalized With Copper Particles for Packaging of Food Products

2020 ◽  
Author(s):  
Olivia López ◽  
María E. Villanueva ◽  
Guillermo J. Copello ◽  
Marcelo A Villar
Keyword(s):  
Inhibitory Concentration ◽  
Corn Starch ◽  
Composite Films ◽  
Thermoplastic Starch ◽  
Biodegradable Films ◽  
Melt Mixing ◽  
Elongation At Break ◽  
Copper Particles ◽  
Starch Films ◽  
Fresh Products

Abstract Biodegradable films based on thermoplastic corn starch (TPS) and copper particles with antimicrobial capacity were developed. Copper nanoparticles (Cu) and silica coated copper microparticles (Si-Cu) in the range of 0.25 to 5 % were used. Composite films were obtained by melt-mixing and subsequent thermo-compression. Particles distribution within TPS matrix and the presence of some pores and cracks, induced by Si-Cu particles, was evaluated by SEM. The presence of both fillers gave to composite films a brown pigmentation and decreased their transparency; these effects were more pronounced at higher particles concentrations. Regarding mechanical properties, copper particles at 1 and 5 % acted as reinforcing agents increasing the maximum tensile strength but their presence lead to a decrease in elongation at break, affecting films ductility. Composites inhibited the growth of Gram+ and Gram- bacteria, demonstrating their antimicrobial capacity. Copper effectively migrated to a simulant of aqueous foods and naked particles concentration in the simulant medium resulted higher than the minimum inhibitory concentration for bacteria.The characteristics and properties of developed composite films make them an interesting material for food primary packaging, mainly for meat fresh products.

Mechanical and Dynamic Mechanical Properties of Degradable Polyurethane Foams with PEG/PCL Mixed Soft Segments

2011 ◽  
Vol 183-185 ◽  
pp. 1611-1615 ◽  
Author(s):  
Jian Hua Wang ◽  
Shuen Liang ◽  
Yan Yan Wang ◽  
Chun Rong Tian ◽  
Xiu Li Zhao
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Strength ◽  
Compressive Strain ◽  
Dynamic Mechanical Properties ◽  
Polyurethane Foams ◽  
Elongation At Break ◽  
Dynamic Mechanical ◽  
Soft Segments ◽  
And Storage

Polyurethane (PU) with mixed poly(ethylene glycol) / poly(ε-caprolactone) (PEG/PCL) soft segments is a representatively kind of degradable polyurethane material. Polyurethane foams (PUF) with mixed PEG/PCL soft segments were synthesized by using one pot method, and their mechanical and dynamic mechanical properties were investigated. Influences of PEG/PCL weight ratio and molecular weight of soft segments on PUF's mechanical and dynamic mechanical properties were studied. The results showed that: with increasing content of PCL, PUF's tensile strength, elongation at break, stress at certain tensile/compressive strain and storage modulus increased gradually; with increasing molecular weight of soft segment, PUF's elongation at break increased, but tensile strength, stress at certain tensile/compressive strain and storage modulus all decreased accordingly; glass transition temperature (Tg) of PUF with various soft segments decreased according to the following sequence: PEG-400, PCL-210N, PEG-1000 and PTMG1000; loss factor of PUF with PEG/PCL mixed soft segments was higher than that of PUF with individual PEG or PCL soft segments.

Preparation and Characterization of Chitosan/poly( Vinyl Alcohol) Composite Packaging Films

2011 ◽  
Vol 332-334 ◽  
pp. 1739-1742 ◽  
Author(s):  
Ling Li ◽  
Zheng Wei Jin ◽  
Jian Qing Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Water Vapor ◽  
Vinyl Alcohol ◽  
Permeability Coefficient ◽  
Composite Films ◽  
Weight Ratio ◽  
Poly Vinyl Alcohol ◽  
Elongation At Break ◽  
Packaging Films

A novel chitosan/poly(vinyl alcohol) composite packaging films were prepared by the casting method, and the effects of chitosan concentration on the structures, mechanical properties, permeability for oxygen and water vapor were discussed in this study. Mechanical properties of these films, which were evaluated by the tensile test and the barrier properties showed that the elongation at break (E) of the composite films decreased rapidly with the addition of chitosan, whereas, the tensile strength (TS) presented an almost opposite trend. Both the water vapour and oxygen transmission rate values were increased with the increasing amount of the chitosan in the composite films. Based on the obtained results, the better property of the composites films would be prepared chitosan/poly(vinyl alcohol) blends at a weight ratio of 3/5, and the tensile strength and elongation at break of the packaging films were 34.12 MPa, 40.24 % respectively. It was also observed that the water vapor permeability coefficient (Pv) and the oxygen permeability coefficient (P) of chitosan/poly(vinyl alcohol) composite packaging films prepared with weight ratio of 3/5 were 1.99×10-15 g•cm/cm2•s•Pa and 7.98×10-16 cm3•cm/cm2•s•Pa respectively. The composite films in this paper can be used in fresh-keeping or other fields as a kind of green packaging material.

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