“…Moreover, the peaks at 1084 and 1180 cm –1 correspond to the symmetric and asymmetric stretching vibration peaks of –C–O–C–. These infrared characteristic peaks of PLA are in agreement with the reported literature , and are kept in the spectra of the other samples. The modified PLA MB spectrum shows a broad peak between 3240 and 3280 cm –1 corresponding to the stretching vibrations of N–H in –NH 2 and O–H in –OH, respectively, meaning the formation of the PDA layer on the surface of PLA MB.…”
The biodegradable
activity antibacterial materials have been widely
applied on food preservation because they not only protect foods from
pathogenic attacks but also relieve environmental pollution. Biodegradable
melt-blown nonwovens (MB) have several advantages over the other materials
in terms of a simpler and more environmentally friendly fabrication
process, higher specific surface area, and lower cost. Herein, polylactic
acid (PLA) MB is first modified by polydopamine (PDA) to activate
the surface. Then, chitosan (CS) and cinnamon essential oil (CEO)
are used to decorate the surface of the modified PLA MB via a simple
one-pot method to prepare CEO/CS@PLA MB with different CEO contents.
Compared with PLA MB, CEO/CS@PLA MB had a rougher surface and larger
average fiber diameter, while the average pore diameter and air permeability
reduced. The input of CEO led to a decrease in the tensile strength
of CEO/CS@PLA MB and an obvious increase in the elongation at break.
The combination of CS and CEO shows excellent synergistic antibacterial
effect. The antibacterial efficiencies of CEO/CS@PLA MB against Escherichia coli and Staphylococcus
aureus enhance with the increase of the CEO content.
When the weight ratio of CS to CEO is 1:2, the antibacterial efficiencies
of CEO2/CS@PLA MB against E. coli and S. aureus are 99.98 and 99.99%,
respectively. When being applied to the preservation of fresh strawberry,
CEO2/CS@PLA MB can effectively inhibit the microbial growth
in strawberry and reduce decay, which extends the shelf time of strawberry.
“…Moreover, the peaks at 1084 and 1180 cm –1 correspond to the symmetric and asymmetric stretching vibration peaks of –C–O–C–. These infrared characteristic peaks of PLA are in agreement with the reported literature , and are kept in the spectra of the other samples. The modified PLA MB spectrum shows a broad peak between 3240 and 3280 cm –1 corresponding to the stretching vibrations of N–H in –NH 2 and O–H in –OH, respectively, meaning the formation of the PDA layer on the surface of PLA MB.…”
The biodegradable
activity antibacterial materials have been widely
applied on food preservation because they not only protect foods from
pathogenic attacks but also relieve environmental pollution. Biodegradable
melt-blown nonwovens (MB) have several advantages over the other materials
in terms of a simpler and more environmentally friendly fabrication
process, higher specific surface area, and lower cost. Herein, polylactic
acid (PLA) MB is first modified by polydopamine (PDA) to activate
the surface. Then, chitosan (CS) and cinnamon essential oil (CEO)
are used to decorate the surface of the modified PLA MB via a simple
one-pot method to prepare CEO/CS@PLA MB with different CEO contents.
Compared with PLA MB, CEO/CS@PLA MB had a rougher surface and larger
average fiber diameter, while the average pore diameter and air permeability
reduced. The input of CEO led to a decrease in the tensile strength
of CEO/CS@PLA MB and an obvious increase in the elongation at break.
The combination of CS and CEO shows excellent synergistic antibacterial
effect. The antibacterial efficiencies of CEO/CS@PLA MB against Escherichia coli and Staphylococcus
aureus enhance with the increase of the CEO content.
When the weight ratio of CS to CEO is 1:2, the antibacterial efficiencies
of CEO2/CS@PLA MB against E. coli and S. aureus are 99.98 and 99.99%,
respectively. When being applied to the preservation of fresh strawberry,
CEO2/CS@PLA MB can effectively inhibit the microbial growth
in strawberry and reduce decay, which extends the shelf time of strawberry.
“…This inorganic filler is typically added to reduce the amount of the more expensive polymer and as whitening agent. The FTIR spectra did not show any variation of the polymer band intensity and position or the appearance of new bands that could be caused by biotic or abiotic hydrolysis or photo degradation via the Norrish II mechanism ( Tosakul et al, 2022 ). The only observed spectral modification was the progressive decreases of calcium carbonate band intensity of the PLA-CaCO 3 sample at day 77 (t4) ( Figure 5A ).…”
IntroductionOnce dispersed in water, plastic materials become promptly colonized by biofilm-forming microorganisms, commonly known as plastisphere.MethodsBy combining DNA sequencing and Confocal Laser Scanning Microscopy (CLSM), we investigated the plastisphere colonization patterns following exposure to natural lake waters (up to 77 days) of either petrochemical or biodegradable plastic materials (low density polyethylene - LDPE, polyethylene terephthalate - PET, polylactic acid - PLA, and the starch-based MaterBi® - Mb) in comparison to planktonic community composition. Chemical composition, water wettability, and morphology of plastic surfaces were evaluated, through Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), and static contact angle analysis, to assess the possible effects of microbial colonization and biodegradation activity.Results and DiscussionThe phylogenetic composition of plastisphere and planktonic communities was notably different. Pioneering microbial colonisers, likely selected from lake waters, were found associated with all plastic materials, along with a core of more than 30 abundant bacterial families associated with all polymers. The different plastic materials, either derived from petrochemical hydrocarbons (i.e., LDPE and PET) or biodegradable (PLA and Mb), were used by opportunistic aquatic microorganisms as adhesion surfaces rather than carbon sources. The Mb-associated microorganisms (i.e. mostly members of the family Burkholderiaceae) were likely able to degrade the starch residues on the polymer surfaces, although the Mb matrix maintained its original chemical structure and morphology. Overall, our findings provide insights into the complex interactions between aquatic microorganisms and plastic materials found in lake waters, highlighting the importance of understanding the plastisphere dynamics to better manage the fate of plastic debris in the environment.
“…The deformation of the -CH 2 group, bending peak of the -CH 3 group, and the out-of-plane bending of the = C-H group were observed at 1442 cm −1 , 1376 cm −1 , and 841 cm −1 , respectively. 33 Figure 2.FTIR spectra of a) NR, b) ENR, and c) ANR.…”
Section: Resultsmentioning
confidence: 99%
“…The deformation of the -CH 2 group, bending peak of the -CH 3 group, and the out-of-plane bending of the = C-H group were observed at 1442 cm À1 , 1376 cm À1 , and 841 cm À1 , respectively. 33 In the spectrum of the ENR, new peaks appeared at 1250 cm À1 and 868 cm À1 correspond to the symmetric and asymmetric stretching vibrations of the epoxy ring. 34 It is also clearly seen that the peak of the = C-H group at 841 cm À1 decreases in intensity.…”
Among biobased and biodegradable polymers, polylactic acid (PLA) is most widely used one. However, its poor mechanical properties need to be enhanced. In this study, PLA blend film with improved mechanical properties were developed without compromising any bio-content. For this, natural rubber derivative with acetate pendant group (ANR) and PLA blend films were prepared. First, natural rubber was epoxidized, and then partial acetylation was achieved by the ring-opening reaction of the epoxy groups. The epoxidation and the acetylation were examined by FTIR analysis. 1H-NMR spectrum revealed a 29% epoxidation and 8.25% acetylation degree. The Tg of natural rubber (−66°C) increased to −41°C and −31°C after epoxidation and acetylation, respectively. The compatibility of ENR and ANR with PLA was evident from the DSC results and Molau test. The morphology of PLA blend film containing 25 wt% of ANR (ANR25) was observed as well-dispersed fine droplets by SEM images. The tensile strength, elastic modulus, and yield strength of ANR25 were measured as 11.6 MPa, 397.3 MPa, and 6.9 MPa, respectively. These values are considerably higher than neat PLA film. Compared to reported studies on PLA toughening so far, increments in both the strength and elongation of ANR25 were observed by tensile tests. Moreover, highest toughness among all samples was determined as 18.8 MJm−3 for ANR25, which is 1.8 times higher than neat PLA. Thus, a strong and tough bio-based PLA blend was developed for film application such as packaging and sheeting.
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