A5057705794- Lignin and Wood Chemistry
- Advanced Cellulose Research Studies
- Enzyme-mediated dye degradation
- Biofuel production and bioconversion
- Enzyme Catalysis and Immobilization
- Chemical Synthesis and Reactions
- Fuel Cells and Related Materials
- Polymer composites and self-healing
- Textile materials and evaluations
- Microbial Metabolites in Food Biotechnology
- biodegradable polymer synthesis and properties
- Free Radicals and Antioxidants
- Natural Fiber Reinforced Composites
- Biochemical and biochemical processes
- Polymer Foaming and Composites
- Advanced oxidation water treatment
- Adsorption, diffusion, and thermodynamic properties of materials
- Psidium guajava Extracts and Applications
- Thermal and Kinetic Analysis
- Microbial Metabolism and Applications
- Food, Nutrition, and Cultural Practices
- Material Properties and Processing
- Lubricants and Their Additives
- Subcritical and Supercritical Water Processes
- Polymer Science and Applications
National Technological University
2015-2025
Consejo Nacional de Investigaciones Científicas y Técnicas
2007-2022
Centro Científico Tecnológico - San Juan
2019
Instituto de Desarrollo Tecnológico para la Industria Química
2007-2013
Centro Científico Tecnológico - Córdoba
2007-2009
Lignosulfonates (LS) are employed as partial substitution of phenol in phenolic resins; but to increase their reactivity they require an initial hydroxymethylation reaction. Dual-detection size exclusion chromatography (SEC) is here for analyzing the evolution molar mass distributions (MMDs) along that The chromatograms were obtained with a UV detector at 254 nm, series differential refractometer (DR). While DR was assumed detect total instantaneous eluent, signal aromatic rings lignin...
ABSTRACT This work investigates the valorization of sodium lignosulfonate, kraft, and organosolv lignins from South America. A detailed characterization their chemical modification by hydroxymethylation through its reaction with formaldehyde were performed. The included measurements moisture, ash, carbohydrate contents, elemental thermogravimetric analysis, functional groups, molar mass distributions Fourier transform infrared spectroscopy, size exclusion chromatography, respectively. Also,...
Laccases are multicopper oxidases that being studied for their potential application in pretreatment strategies of lignocellulosic feedstocks bioethanol production. Here, we report the expression and characterization a predicted laccase (LAC_2.9) from thermophilic bacterial strain Thermus sp. 2.9 investigate its capacity to delignify biomass. The purified enzyme displayed blue color typical laccases, showed strict copper dependence retained 80% activity after 16 h at 70 °C. At 60 °C,...
Reducing the consumption of phenol during synthesis phenolic resins is great technological and scientific interest because its economic environmental implications.In this work, use hydroxymethylated lignins as a partial replacement for in resol phenol-formaldehyde used production decorative laminates was experimentally studied.The work involved: i) industrial traditional modified resols with 10%w/w sodium lignosulfonate kraft-type lignin; ii) impregnation krafttype paper produced resins;...
The effect of lignin nanoparticles (LNPs) on the crystallization kinetics poly(ethylene oxide) (PEO) is examined. Lignin from spruce and ionic isolation was used to prepare LNPs with a number-averaged diameter 85 nm (with relatively large polydispersity) by an ultrasonication method. PEO-based nanocomposites four different LNP contents (5, 10, 15, 20 wt %) were prepared subject isothermal nonisothermal protocols in series experiments. Scanning electron microscopy (SEM) images showed...
ABSTRACT In the first part of this sequel, an experimental investigation on synthesis linear segmented polyurethanes was presented, that included estimation kinetic constants at 60°C for prepolymerization and finishing stages. This work presents two comprehensive mathematical models simulate mentioned prepolymerizations, in reactions between poly(tetramethylene oxide) PTMO macrodiols excess methylene diphenyl diisocyanate. The require to input molar mass distribution (MMD) initial macrodiol....
This paper investigates the effect of different bio-based additives on expansiveness an Argentinian natural clayey soil (CR-clay). CR-clay was characterised to determine (a) Atterberg parameters and other index properties, (b) particle size distribution by laser diffraction, (c) specific surface area (S e ) cationic exchange capacity methylene blue method, (d) mineralogy using X-ray (e) functional groups Fourier transform infrared spectroscopy (FTIR) (f) free swelling pressure odometer....
Abstract A novel mathematical model is presented on the methylolation of melamine with formaldehyde at 48°C and pH 9.0. The assumes an instantaneous hydration/dehydration mechanism Gordon et al. (J Appl Polym Sci 1966, 10, 1153). 24 kinetic constants were adjusted to experimental measurements by Tomita 1977, 15, 2347). predicts evolutions comonomers nine methylolated species. This first article a series that aims developing detailed for industrial synthesis melamine–formaldehyde resins. ©...
The reduction of phenol and/or formaldehyde consumption during phenolic resin synthesis is great technological and scientific interest because its economic environmental implications. In this work, the addition sodium lignosulfonate as partial replacement in resol base resins used for decorative laminates production experimentally studied. work involves: i) characterization reactivation lignosulfonate, ii) industrial traditional modified resols by 10%w/w phenol, iii) impregnation Kraft-type...
The hydroxymethylation of phenol in alkaline conditions is the first step synthesis resols, which must be later cured for production final articles. A mathematical model presented. It based on kinetic mechanism by Freeman and Lewis (J. Am. Chem. Soc. 1954, 76, 2080–2087) includes a set side reactions. Arrhenius expressions seven constants at pH 8–10 temperatures 30–57 °C, absence methanol, were recalculated from reported Zavitsas et al. Polym. Sci., Part A-1: 1968, 6, 2541–2559), order to...
Abstract This work investigates five reactions between melamine (M) and formaldehyde (F) at pH = 9.0, with initial F : M ratios of 2. The samples were analyzed by size exclusion chromatography (SEC), volumetric techniques, ( 1 H 13 C) NMR. Condensation was quantified the SEC measurements. In experiments 38 48°C, condensation almost negligible, reversibility methylolation determined that equilibriums reached in primary, secondary, tertiary amines. 60, 70, 90°C, significant, but all cases,...
The present study focuses on the assessment of natural vegetal extracts in inhibition bacteria altering Vienna sausages whose growth becomes evident vacuum packed product after two to three weeks refrigerated storage causing packages swell. different were obtained by means steam stripping, microwave assisted extraction and ultrasound extraction. Apart from these extracts, commercial essential oils, pure compounds kingdom solutions also evaluated. For each microbial sensitivity tests carried...
Abstract A novel mathematical model is presented for the reaction between melamine (M) and formaldehyde (F) at pH = 9.0 temperatures 38 90°C. It based on a kinetic scheme that includes reversible methylolations, irreversible formation of (unsubstituted) methylene bridges, ether instantaneous dissolution M, equilibrium hydration/dehydration F. The predicts distributions molecular weights functionalities evolving MF resin. Arrhenius expressions were adjusted seven constants basis measurements...