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Scheme showing hydrogen bonding (-) and carboxymethylation of cellulose.
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In this work, CMC was synthesized from cellulose obtained from coir fibres. The obtained CMC yield was about 64.0%. The Degree of Substitution value obtained was 0.44. The spectral pattern and thermogravimetric analysis of the synthesized CMC and cellulose were evaluated using FT-IR, XRD, and TGA/DTG. Characterization of the cellulose and CMC revea...
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... in this study a comparative spectral analysis of the synthesized CMC and cellulose obtained from coir fibre via a green synthetic method (hydrogen peroxide liquid phase oxidation of cellulose) was carried out and studied using FT-IR, XRD and TGA/DTG. Figure 1 shows a schematic representation of carboxymethylation process which proceeds via SN2 mechanism. The amount of hydrogen bonding obtained in CMC as compared to ordinary native cellulose reduces due to the etherification of OH group in native cellulose [2,32]. ...
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The aim of the current study was synthesis and characterization of CMC and further evaluation of its emulsion stabilizing properties for preparation of pharmaceutical and cosmetic emulsions. Carboxymethyl chitosan (CMC) with high degree of substitution (50 %) has been synthesized and further characterization of resulting product by FTIR, NMR spectr...
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Citations
... The peak at 2895 cm −1 in untreated sugarcane bagasse is attributed to C H stretching in methyl and methylene groups. 31 The absorption band (2885 cm −1 ) found by other researchers was intangible compared to the results of this study. 16 The bands at 1604 cm −1 , 1319 cm −1 , 1242 cm −1 , and 1158 cm −1 in untreated sugarcane bagasse are attributed, respectively, to the stretching vibrations of N H bending (amine), O H bending, C O stretching (acetyl), and N H stretching (organic sulfate). ...
BACKGROUND
The demand for green products is pushing industries to search for more eco‐friendly materials, especially for food packaging applications. Starch biopolymer has been recognized as biodegradable material that can be produced from various plants. However, the strength of starch‐based bioplastic retards their widespread application. Simultaneously, the high amount of agricultural waste produced by the food industry has been a growing environmental issue. Incorporating agro‐waste fibers as a biofiller in starch‐based bioplastic can improve the properties of the bioplastic, allowing its use in various applications. Thus, this study aims to evaluate the effect of chemical treatment on the structural, thermal, and mechanical properties of sugarcane bagasse as filler for starch‐based bioplastic.
RESULTS
Results showed that alkaline treatment improved surface roughness and freed it of surface impurities. Results revealed that the thermal stability and mechanical properties improved significantly with the incorporation of sugarcane bagasse (SB) loading into potato starch (PS). The highest tensile strength (5.30 MPa) and Young's modulus (28.72 MPa) were exhibited by the sample with 6% SB loading and further increments of SB led to a decrease in the strength of the biopolymer.
CONCLUSION
The incorporation of alkali‐treated SB could increase and enhance the tensile strength and thermal stability of the bioplastic. This would contribute to reinforced materials that will allow for the application of PS as a new potential biodegradable material. Thus, it reduces the disposal period process and has great potential as an environmentally friendly, biodegradable, and renewable material. © 2022 Society of Chemical Industry (SCI).
... The thermograms are shown in Figure 2 and melting points, enthalpies and crystallinity indices are presented in Table 2 shows that results proved the CMC of the amorphous structure of polymers and obstructed crystallization. 33,34 Melting points of ocular films have exposed a decline to lower temperatures with larger peaks compared to the bulk polymer by giving variable enthalpy values indicating several thermal transitions as well. 35 Decline in melting points of CHI%1 and CHI-DRZ%1 formulation was detected as 10 °C when added the carboxymethyl cellulose instead of CHI caused more decrease in case of CMC%1 and CMC-DRZ1%. ...
Objectives:
This study constructed dorzolamide (DRZ)-loaded ophthalmic implants for extended drug delivery and increased drug retention.
Materials and methods:
Carboxymethyl cellulose (CMC) and chitosan (CHI) were used to describe the ophthalmic implants. The implants were prepared by the solvent casting technique in presence of polyethylene glycol 6000 (PEG 6000) as plasticizer. Physicochemical characterization studies including mechanical characteristics [tensile strength (TS), elongation at break, and Young's modulus], bioadhesion studies, and in vitro and ex vivo drug release studies were conducted.
Results:
TS of drug-loaded ophthalmic implants was 10.70 and 11.68 MPa, respectively. Elongation at break of CMC and CHI implants was 62.00% and 59.05%, respectively. The in vitro release profiles fit into Higuchi type kinetic model. Ex vivo release study results for both implants were correlated with in vitro release investigations.
Conclusion:
CMC and CHI-based implants provide extended drug delivery. Implants prepared using CMC provided a significantly slower in vitro release rate, and drug retention on ocular surfaces increased. Thus, it has been concluded that DRZ-loaded CMC implants could provide effective treatment for glaucoma.
... As reported, the degradation process of macromolecules such as polysaccharides, in general, goes through the following steps: dehydration, depolymerization and the decomposition [52,53]. The initial mass loss below 200 • C mainly results from the removal of free water [54], the loss at 275 • C-350 • C the random cleavage of glycosidic bonds [55], and the loss at 300-600 • C the decomposition of the saccharide ring structure [56]. Relative to covalent crosslinking, noncovalent crosslinking can be easier broken at around 300 • C. The increase in weight loss below 100 • C indicates more free water in the porous network, confirming the increase of the porosity of CS/γ-PGA/DOE hydrogel. ...
Hydrogels have been widespreadly used in various fields. But weak toughness has limited their further applications. In this study, Dendrobium officinale enzyme (DOE) was explored to improve chitosan/γ-poly(glutamic acid) (CS/γ-PGA) hydrogel in the structure and properties. The results indicated that DOE with various sizes of ingredients can make multiple noncovalent crosslinks with the skeleton network of CS/γ-PGA, significantly changing the self-assembly of CS/γ-PGA/DOE hydrogel to form regular protuberance nanostructures, which exhibits stronger toughness and better behaviors for skin care. Particularly, 4% DOE enhanced the toughness of CS/γ-PGA/DOE hydrogel, increasing it by 116%. Meanwhile, water absorption, antioxygenation, antibacterial behavior and air permeability were increased by 39%, 97%, 27% and 52%.
... where the presence of NaCMC diminishes the PVA chains ability to pack into crystals [43] . The PVA-CMC layers revealed that the increase of freeze-thawing cycles displaced the band at 1593 cm -1 (NaCMC's ν(-COO) [44] ) to 1566 cm -1 , which indicate the effectiveness of the "crosslinking" [45] . In addition, the two bands at 1087 cm -1 (PVA's δ(C-O-H) [46] ) and at 1060 cm -1 (NaCMC's ν(OCH-O-CH 2 ) [47] ) cannot be distinguished in layers submitted to more freeze-thawing cycles, where only one band at 1087 cm -1 can be observed. ...
PVA cryogels are well established as candidate biomaterials for wound healing applications but are not themselves biodegradable or antimicrobial. Blending PVA with NaCMC (CMC) or gelatin (G) can increase the gel’s ability to swell and would introduce a degree of biodegradability. The incorporation of appropriate amounts of a natural antimicrobial/healing agents, such as honey (H), would contribute to the gels properties. The present work addresses the development and characterization of layered gels (PVA-H, PVA-CMC-H and PVA-G-H, with empty PVA, PVA-CMC, PVA-G gels presented as controls). The gels were characterized by FTIR, DSC, in vitro analysis of swelling and microbiological (S. aureus) effects. Addition of gelatin, NaCMC and honey to PVA diminished the PVA chains’ ability to pack into crystallites. Samples containing honey swelled less and presented higher weight loss/biodegradability than samples without honey. Only the honey-laden PVA-CMC and PVA-G presented activity against S. aureus.
... The absorption bands at 2908.65 and 2910.58 cm -1 for the NaOH treated coir fibres and untreated coir fibre, respectively, may be attributed to C-H stretching in methyl and methlyene groups (Ikhuoria et al. 2017). The absorption band at 1724.36 cm -1 in untreated coir fibre corresponds to the carbonyl (C=O) stretching vibrations of carboxyl and acetyl groups in hemicelluloses. ...
... The carboxyl and acetyl groups in the hemicelluloses were soluble in aqueous alkaline solution, thus causing the band to disappear in NaOH-treated coir fibres for both 24 and 48 h. This finding is in agreement with previous study which reported that alkali treatment removed hemicelluloses (Abraham et al. 2013;Akhtar et al. 2016;Ikhuoria et al. 2017;Sinha & Rout 2009;Valadez-Gonzalez et al. 1999). ...
The alkaline treatment with 5 wt. % sodium hydroxide (NaOH) solution at room temperature for 24 and 48 h was performed on coir fibre. The structural characterisation, thermal degradation and water absorption ability of the untreated and NaOH-treated coir fibre polymer composites have been studied. Scanning electron microscope (SEM) images showed that coir fibres treated with NaOH have rough surface texture and the roughness of the fibre surface becomes significant as the duration of the NaOH treatment increased. Fourier transform infrared (FTIR) spectra confirmed that NaOH treatment removed hemicelluloses as evidenced by the absence of absorption bands at 1724.36 cm ⁻¹ and changes the absorption intensity at bands 1244.09 cm ⁻¹ and 1249.87 cm ⁻¹ due to the loss of lignin. NaOH-treated coir fibre composites demonstrated better thermal stability at low temperature degradation. At high temperature, the thermal stability was reduced due to the decreased of residual lignin content. The water absorption of the NaOH-treated coir fibre composites was lower than untreated coir composite contributed by better interfacial adhesion between the NaOH-treated coir fibre to epoxy resin. © 2019 Penerbit Universiti Kebangsaan Malaysia. All rights reserved.
The main objective of this study was to evaluate the effect of the addition of different concentrations of CMC (0, 20, 40, 60, 80 and 100%) on the mechanical and water vapor barrier properties in corn starch films produced by casting. The addition of CMC 40% was sufficient to significantly increase its mechanical properties (tensile strength, elongation at break and elastic modulus), and water vapor barrier of the starch films, thus improving its functionality as a packaging material for food. CMC incorporation led to a small reduction in the thermal stability of the films. CMC in low content dispersed well in the starch matrix, ensuring interaction between its constituents that formed a network structure, thus improving mechanical properties and making diffusion of water difficult.
