Forensic Engineering of Advanced Polymeric Materials—Part VII: Degradation of Biopolymer Welded Joints

Sikorska, Wanda; Zięba, Magdalena; Musioł, Marta; Kowalczuk, Marek; Janeczek, Henryk; Chaber, Paweł; Masiuchok, Olha; Demchenko, Valeriy; Talanyuk, V.; Iurzhenko, Maksym; Puskás, Judit E.; Adamus, Grażyna

doi:10.3390/polym12051167

Cited by 12 publications

(8 citation statements)

References 33 publications

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“…At treatment temperatures of 140–150°C, PLA remains amorphous, and seal temperatures are only slightly elevated, compared to untreated PLA 120 . Finally, it is shown that the chemical structure and molar mass of PLA, before and after conductive heating, are not changed, based on nuclear magnetic resonance spectra and gel permeation chromatography 121 …”

Section: Polyestersmentioning

confidence: 93%

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Seal materials in flexible plastic food packaging: A review

2023

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Flexible packaging has many advantages in the food industry, arising from low weight, formability, multilayer complexity and cost. Heat sealing is a very efficient technique to close flexible food packaging. Currently, many thermoplastic materials are used in seal layers. A seal can be formed when these materials are heated and brought into contact; thereafter, polymer chains diffuse across the seal interface and entangle. Hydrogen bonds, polar and ionic interactions are molecular forces that can come into play, depending on the thermoplastic materials that are used in the seal layer. Bonds between identical polymers, referred to as autohesion, are formed in pouch applications (e.g., horizontal and vertical form-fill-seal packages). In lidding applications, the flexible film is sealed to a rigid cup, tray or bottle, whereby bonds can be formed between non-identical polymers because the materials are often provided by different suppliers. All heat seal technologies imply heating of seal layers but differ in the heating principle. In the food industry and in most scientific seal studies, the seals of mono-and multilayered packaging are mainly formed by conductive heating. Recently, the use of emerging technologies, such as ultrasonic and laser heating, is increasingly described in recent papers. Applied seals are characterized by strength after a specified cooling time. Immediately after heating, this strength is referred to as hot tack. A good seal performance is crucial to guarantee food safety and quality. Besides strength, tightness is important to prevent food degradation, caused by microorganisms and external gases, and to keep aromatic gases inside the package. This review aims to give a literature overview that can support stakeholders in the food industry to improve and optimize the material selection in flexible packaging, in order to obtain seals with desired tightness and strength. Heat seal studies on materials and seal technology of flexible food packaging, such as pouches and lidding films, are considered. Scientific data are categorized from a materials' perspective, based on chemical structure, which is revealed by chemical and thermal analysis. A majority of the seal studies is categorized in a first section on polyolefins as seal layers. The following sections describe the seal functionality of (i) ethylene copolymers, such as ionomers; and (ii) polyesters, such as poly (ethylene terephthalate), pol (lactic acid) and poly (butylene succinate). The role of plasticizers, fillers and other

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Section: Polyestersmentioning

confidence: 93%

“…Sealed films with poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) are used in a shelf life study, but no information is shared on the seal performance and settings 134 . Another study evaluates chemical structure and molar mass of PHBV, before and after conductive heating, but has not found any changes 121 …”

Section: Polyestersmentioning

confidence: 99%

Seal materials in flexible plastic food packaging: A review

2023

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“…Thermal transitions of patterns were analyzed by differential scanning calorimetry (DSC) under nitrogen flow using a TA-DSC Q2000 apparatus (TA Instruments, Newcastle, DE, USA) from 20 to 200 °C at a heating rate of 20 °C/min. 38 2.3.6. Antimicrobial Activity.…”

Section: Methodsmentioning

confidence: 99%

Preparation, Characterization, and Antimicrobial and Antiviral Properties of Silver-Containing Nanocomposites Based on Polylactic Acid–Chitosan

Iurzhenko

2022

ACS Appl. Bio Mater.

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Antimicrobial and antiviral nanocomposites based on polylactic acid (PLA) and chitosan were synthesized by a thermochemical reduction method of Ag + ions in the PLA-Ag + -chitosan polymer films. Features of the structural, morphological, thermophysical, antimicrobial, antiviral, and cytotoxic properties of PLA-Ag-chitosan nanocomposites were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and antiviral, antimicrobial, and cytotoxic studies. The effects of temperature and the duration of reduction of Ag + ions on the structure of PLA-Ag-chitosan nanocomposites were established. During the thermochemical reduction (T = 160 °C, t = 5 min) of silver palmitate ions in PLA-Ag + -chitosan polymer films, Ag nanoparticles with an average size of 4.2 nm were formed. PLA-Ag-chitosan polymer nanocomposites have strong antimicrobial activity against S. aureus and E. coli strains. In particular, for PLA-chitosan samples containing 4% Ag, the diameters of the S. aureus and E. coli growth inhibition zones were 25.8 and 25.0 mm, respectively. The antiviral activity of the nanocomposites against influenza A virus, herpes simplex virus type 1, and adenovirus serotype 2 was also revealed. The PLA-4%Agchitosan nanocomposites completely inhibited the cytopathic effect (CPE) of herpes virus type 1 by 5.12 log 10 TCID 50 /mL (high antiviral activity) and the development of the CPE of influenza virus and adenovirus by 0.60 and 1.07 log 10 TCID 50 /mL (relative antiviral activity). The obtained nanocomposites were not cytotoxic; they did not inhibit the viability of MDCK, BHK-21, and Hep-2 cell cultures.

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“…Recently, polymer nanocomposites containing nanoparticles of metals such as silver, copper and zinc oxide have attracted the most attention due to their pronounced pharmacological effects, including antimicrobial, antiviral, anti-inflammatory, immunomodulatory, and high stability in extreme conditions [5][6][7][8][9]. A promising polymer for the creation of antimicrobial and antiviral silver-containing nanocomposites is polylactide (PLA), which has significant advantages over other polymers, namely it is thermoplastic and is characterized by high mechanical strength, biocompatibility and non-toxicity [10,11]. These benefits allow the use of PLAs for biomedical packaging, food packaging, and 3D printing technology.…”

Section: Introductionmentioning

confidence: 99%

Structure-Morphology-Antimicrobial and Antiviral Activity Relationship in Silver-Containing Nanocomposites Based on Polylactide

et al. 2022

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Green synthesis of silver-containing nanocomposites based on polylactide (PLA) was carried out in two ways. With the use of green tea extract, Ag+ ions were reduced to silver nanoparticles with their subsequent introduction into the PLA (mechanical method) and Ag+ ions were reduced in the polymer matrix of PLA-AgPalmitate (PLA-AgPalm) (in situ method). Structure, morphology and thermophysical properties of nanocomposites PLA-Ag were studied by FTIR spectroscopy, wide-angle X-ray scattering (WAXS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) methods. The antimicrobial, antiviral, and cytotoxic properties were studied as well. It was found that the mechanical method provides the average size of silver nanoparticles in the PLA of about 16 nm, while in the formation of samples by the in situ method their average size was 3.7 nm. The strong influence of smaller silver nanoparticles (3.7 nm) on the properties of nanocomposites was revealed, as with increasing nanosilver concentration the heat resistance and glass transition temperature of the samples decreases, while the influence of larger particles (16 nm) on these parameters was not detected. It was shown that silver-containing nanocomposites formed in situ demonstrate antimicrobial activity against gram-positive bacterium S. aureus, gram-negative bacteria E. coli, P. aeruginosa, and the fungal pathogen of C. albicans, and the activity of the samples increases with increasing nanoparticle concentration. Silver-containing nanocomposites formed by the mechanical method have not shown antimicrobial activity. The relative antiviral activity of nanocomposites obtained by two methods against influenza A virus, and adenovirus serotype 2 was also revealed. The obtained nanocomposites were not-cytotoxic, and they did not inhibit the viability of MDCK or Hep-2 cell cultures.

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Forensic Engineering of Advanced Polymeric Materials—Part VII: Degradation of Biopolymer Welded Joints

Cited by 12 publications

References 33 publications

Seal materials in flexible plastic food packaging: A review

Seal materials in flexible plastic food packaging: A review

Preparation, Characterization, and Antimicrobial and Antiviral Properties of Silver-Containing Nanocomposites Based on Polylactic Acid–Chitosan

Structure-Morphology-Antimicrobial and Antiviral Activity Relationship in Silver-Containing Nanocomposites Based on Polylactide

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