CMC Samples Research Articles

Characterization and Evaluation of Commercial Carboxymethyl Cellulose Potential as an Active Ingredient for Cosmetics

Carboxymethyl cellulose is the most used water-soluble cellulose with applications in industries such as food, cosmetics, and tissue engineering. However, due to a perceived lack of biological activity, carboxymethyl cellulose is mostly used as a structural element. As such, this work sought to investigate whether CMC possesses relevant biological properties that could grant it added value as a cosmeceutical ingredient in future skincare formulations. To that end, CMC samples (Mw between 471 and 322 kDa) skin cell cytotoxicity, impact upon pro-collagen I α I production, and inflammatory response were evaluated. Results showed that samples were not cytotoxic towards HaCat and HDFa up to 10 mg/mL while simultaneously promoting intracellular production of pro-collagen I α I up by 228% relative to the basal metabolism, which appeared to be related to the highest DS and Mw. Additionally, CMC samples modulated HaCat immune response as they decreased by ca. 1.4-fold IL-8 production and increased IL-6 levels by ca. five fold. Despite this increase, only two samples presented IL-6 levels similar to those of the inflammation control. Considering these results, CMC showed potential to be a more natural alternative to traditional bioactive cosmetic ingredients and, as it is capable of being a bioactive and structural ingredient, it may play a key role in future skincare formulations.

Low And Highly Substituted Carboxymethyl Cellulose Synthesis From Powdered And Microcrystalline Cellulose

The conditions for low and highly substituted water-soluble carboxymethyl cellulose synthesis based on microcrystalline and powder cellulose by the suspension method have been investigated. Accordingly, it was obtained CMC water-soluble samples with 0.38-0.40 substitution degree based on microcrystalline and powder cellulose. And at one stage, there were obtained CMC samples with a high degree of substitution (1.4) by carboxymethylation so called polyanionic cellulose.

Investigation of a single-layer EBC deposited on SiC/SiC CMCs: Processing and corrosion behaviour in high-temperature steam

Two rare earth monosilicates (Yb2SiO5, and Lu2SiO5) were deposited using a low-cost coating application method to produce a single-layer coating. RE- oxides slurries were dip coated on oxidised CMC samples and subsequently heat treated at high temperature to ensure reaction between SiO2 and RE-oxides to form the RE-monosilicate. A single, continuous, homogeneous thick coating of 25 μm was obtained. X-ray diffraction (XRD) confirmed formation of, RE-monosilicates in Yb and Lu silicate systems. Coated samples were exposed to 90% H2O static steam environment at 1350 °C for 25, 50, 100, and 150 h. Scanning Electron Microscopy (SEM) indicated that both coatings adhered strongly to the substrate. Coating thickness reduced from 22 μm to 11 μm for Yb-coating and 13 to 4 μm for Lu-coating with increasing corrosion time from 25 to 150 h, however there was no significant attack of the CMC for all steam exposure times.

The bovine colostrum microbiome and its association with clinical mastitis

In an effort to characterize colostrum microbial diversity and its potential associations with early-lactation clinical mastitis, we used high-throughput sequencing of the 16S rRNA gene to investigate the bovine colostrum microbiome. A prospective observational study was conducted that included 70 Holstein cows; colostrum samples were collected from all 4 mammary gland quarters. Colostrum samples were categorized according to whether the quarter was diagnosed (CMC) or not diagnosed (NCMC) with clinical mastitis during the first 30 d postpartum. Colostrum samples were dominated by Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, Fusobacteria, and Tenericutes phyla, with the 6 most common taxa [order (o), family (f), and genus (g)] being g_Staphylococcus, g_Prevotella, f_Ruminococcaceae, o_Bacteroidales, o_Clostridiales, and g_Pseudomonas. The colostrum microbiota of primiparous cows was significantly richer (higher number of bacterial species) than that of multiparous cows, and differences in colostrum taxonomic structure between parities were also observed. The microbial community of NCMC samples of primiparous cows was significantly more diverse than that of CMC samples, and the relative abundances of the Tenericutes and Fusobacteria phyla as well as the Mycoplasma and Fusobacterium genera were significantly higher in NCMC than in CMC samples of primiparous cows. The colostrum core microbiome, defined as the bacterial taxa common to all colostrum samples examined, was composed of 20 taxa and included bacterial genera already known to be associated with mastitis (e.g., Staphylococcus, Mycoplasma, and Streptococcus spp.). Our results indicate that the colostrum microbiome of primiparous cows differs from that of multiparous cows, and it harbors some diversity and taxonomic markers of mammary gland health specific to primiparous cows only.

The bonding of anesthetics and antibiotics on the carboxymethylcellulose

The preparation of biologically active material is one of the most interesting trends in the chemical modification of cellulose. The possibility of obtaining biologically active cellulosic material by sorption of procaine hydrochloride and gentamicin sulphate on CMC was investigated in this paper. The sorption of therapeutics on CMC samples with different degree of substitution was carried out in water solutions of anesthetic and antibiotic, while the desorption was done in 0.95% NaCl solution. The amount of bonded and released therapeutics was determined by UV spe-ctrophotometry. It was found that degree of substitution of car-boxymethylcellulose and concentration of chemotherapeutic water solution have significant influence on the amount of bonded anesthetic and antibiotic. The maximum amount of bonded chemotherapeutic was 72.15 mg of procaine hydrochloride and 165.49 mg of gentamicin sulphate per gram CMC. In both cases the amounts of bonded chemotherape-utics correspond to the concentration of local anesthetic and antibiotic preparation that are used in therapeutic purposes.

Formation of Aromatic and Other Unsaturated End Groups in Carboxymethyl Cellulose During Hot Alkaline Treatment

Carboxymethyl cellulose (CMC, DS 0.58) was treated in solutions of sodium hydroxide (0.001–1 M) at 95 °C. The treated (1–12 h) CMC samples were purified by dialysis and analyzed by UV spectroscopy and by UV resonance Raman spectroscopy (UVRRS) with excitation at 244 nm. A UV absorption maximum at 265 nm and a UVRR signal at 1650 cm−1 were indicative of formation of \(\alpha,\beta\)-conjugated aldehyde end groups in CMC through \(\beta\)-elimination. Another strong UVRR band at 1610 cm−1 gave evidence on conversion of some of the \(\alpha,\beta\)-conjugated aldehyde end groups to alkali stable aromatic structures.

Carboxymethylcellulose derivatives with low hydrophilic properties

New kinds of cellulose derivatives have been obtained by modification of sodium and lithium carboxymethylcellulose (NaCMC and LiCMC, respectively) with commercial octadecylisocyanate (OctI) and hexamethylene-diisocyanate (HDI). The CMC samples were obtained from sugar cane bagasse pulps using sodium hydroxide and anthraquinone mixture. The structural changes of modified samples were observed using infrared spectroscopy (IR), solid state 1 3 C NMR and thermal analysis (TGA). The samples surfaces were visualized using scanning electron microscopy (SEM) method. The presence of characteristic urethane group absorption bands in the region of 1650-1720 cm - 1 in IR spectra and at 159 ppm in 1 3 C NMR spectra indicates the formation of the product.

Carboxymethyl Cellulose from Waste Lignocellulosic Pulps Produced by a Fast Soda/Aq Process

Cellulose pulps were prepared from ground branch wood from pine and poplar and ground wheat straw by a fast soda/anthraquinone pulping. This process used high pulping temperatures and short residence times. Various combinations of temperature and time were used so that the H factor for pulps from pine and poplar was a constant 2700 while for pulps from wheat straw it was 270. The chemical composition of the resulting cellulose pulps was characterized and the possibility of synthesizing carboxymethyl cellulose from them was evaluated. The degree of substitution of our CMCs was found to be dependent upon the source of the lignocellullosic material, but independent of the pulping conditions for a specific substrate, (0.75 for pine, 0.82 for poplar and 0.89 for wheat straw). The rheological properties, the intrinsic viscosity and the molecular weight of the CMCs were found to be dependent on the pulping conditions for each lignocellulosic tested. The molecular weights of our CMC samples were 219,000 to 316,000 for pine, 335,000 to 375,000 for poplar, and 350,000 to 383,000 for wheat straw. The molecular weights were highest for the pulps cooked at low temperatures.

Water-absorbing characteristics of acrylic acid-grafted carboxymethyl cellulose synthesized by photografting

Cellulosic absorbents for water were synthesized by photografting (λ > 300 nm) acrylic acid (AA) onto fiberous carboxymethyl cellulose (CMC, degree of substitution [DS] = 0.1–0.4) at 30°C in the presence of N,N′-methylenebisacrylamide as a crosslinker. The CMC sample was pretreated with hydrogen peroxide in the presence of sulfuric acid to prepare CMC peroxides with a peracid type as a polymeric photoinitiator. The peroxides were active for the photografting and AA could be grafted onto CMC with percent graftings higher than 150% by photoirradiation of 10 min at 30°C. The amount of water absorbed increased with increasing percent grafting of AA and DS of CMC. The amount was reduced considerably when the absorbents were prepared by the photografting of AA onto crosslinked CMC in the absence of the crosslinker. Graft copolymers which display a decreasing water absorbency as a function of temperature were prepared by two methods: In the first synthesis method, AA and N-isopropylacrylamide (NIPAAm) binary monomers were graft-copoly-merized onto CMC samples using photoinitiation. In the second method, photografting of AA was followed by a second-step photografting of NIPAAm to produce a terpolymer with two types of side chains of differing repeat unit composition on the CMC substrate. Graft copolymers formed by both methods showed decreasing water absorbency as temperature increased with losses in water absorbency of up to about 60% as the temperature was increased above 30°C. Effects of NIPAAm composition and corsslinker content in the graft copolymers on the decreasing water absorbency as a function of temperature were also examined. © 1996 John Wiley & Sons, Inc.

Viscometric and diffusion investigations in the cellulose/cadoxen/water system

AbstractBy means of viscometric and diffusion measurements with CMC samples of DS ≈ 1 and different molecular weight in cadoxen (conventional cellulose solvent)/water systems the minimum cadoxen concentration still securing a valid evaluation of the data was assessed. The influence of the procedure of preparation of the CMC solution was investigated. A limiting ratio of cadoxen: water of about 1:10 was found. The results are discussed on the basis of a change in ionic strength on addition of cadoxen to a CMC/water system resulting in diminishing of polyelectrolyte effects.

Synthesis and applications of reactive carbohydrates. III. Preparation and methylolation of polyacrylamide‐carboxymethyl cellulose graft copolymers

AbstractCarboxymethyl cellulose (CMC) was treated with HCl at 80°C for different time periods (15 – 60 min). The hydrolyzed CMC samples as well as the original sample were graft copolymerized with acrylamide using K2S2O8 as initiator. It was disclosed that the increasing duration of acid hydrolysis is accompanied by a progressive increment in the copper number of CMC, meanwhile its carboxyl content decreases. Acid hydrolysis enhances significantly the susceptibility of the CMC toward grafting. The latter reduces the copper number of the hydrolyzed CMC samples most probably via conversion of the aldehydic to carboxylic groups under the action of K2S2O8 during grafting. Grafting also reduces the carboxyl content of the original CMC sample while increasing those of the hydrolyzed CMC samples. Methylolation of the polyacrylamide‐CMC graft copolymers results in reactive finishes. When the latter were applied to cotton fabric according to the conventional pad‐dry‐cure method followed by a thorough washing, the fabric retained ca. 86% of the finish derived from the copolymer of CMC and 92% of finishes derived from the copolymers of hydrolyzed CMC.

Determination of the molecular weight distribution of cellulose on calibrated gel columns

AbstractCMC samples obtained by gel filtration on a preparative scale were used to calibrate an agarose column. The relation between molecular weight and the peak elution volume for monodisperse samples were calculated as well as the relation between band broadening and the peak elution volume. In the calculations of the molecular weight distribution curves of the studied CMC samples, consideration was given to the variable band broadening by proper transformations of the experimental data, thus making it possible to obtain numerical solutions free from oscillations. The method admits a rapid determination of the molecular weight distribution of cellulose and related materials.