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Aurelio Ramírez-Hernández

Aurelio Ramírez-Hernández
Centro de Investigaciones Científicas, Instituto de Química Aplicada, Universidad del Papaloapan, Circuito Central 200 Parque Industrial, San Juan Bautista Tuxtepec, Oaxaca, México.

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27
Publications
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188
Citations

Publications

Publications (27)
Article
Full-text available
The banana starch reaction with polyethylene using ethylene carbonate was carried out by varying the starch/ethylene carbonate mass ratio (50–1000%). The starch-g-PE mass yield reached 89% mass conversion and a grafting yield of 0.52 when a starch/EC = 0.5 ratio was used, while the mass yield decreased until reaching a value of 26% when the starch/...
Article
Chemical modification of banana starch (Musa paradisiaca L.) with the degradation products of virgin and bottle waste of polyethylene terephthalate was carried out in situ. The modified starch was characterized by FTIR and NMR, which allowed proposing three chemical structures. SEM micrographs showed that the morphology of the modified starch granu...
Article
Terpenes with olefin methyl branches and bifunctional hydroxyl groups were used as initiators in the ring-opening polymerization of ε-caprolactone (CL) catalyzed by ammonium decamolybdate (NH4)6[Mo7O24], resulting in α-hydroxyl-ω-olefin poly(ε-caprolactone) (PCL) (Co–PCL–OH). The degree of polymerization was kept low (5 and 10) in all the species t...
Article
Full-text available
Synthesis of the starch/silicone oil composite carried out and its structural characterization by FTIR, Raman and 29Si NMR allowed to identify functional groups of the composite. The synthesis conditions were a starch/silicone oil mass ratio of 2.0 and a temperature of 150 oC to obtain a yield of 84.63 %. SEM analysis showed that the starch granule...
Preprint
Full-text available
Synthesis of the starch/silicone composite carried out and its structural characterization by FTIR, Raman and ²⁹ Si NMR allowed to identify functional groups of the composite. The synthesis conditions were a starch/silicone mass ratio of 2.0 and a temperature of 150 o C to obtain a yield of 84.63 %. SEM analysis showed that the starch granules were...
Article
Banana starch was modified with B bis(2-hydroxyethyl) terephthalate and its instrumental characterization allowed to propose a chemical structure. In the carbon 6 (C6) of the starch the modification reaction was carried out. The morphology of starch changes due to its chemical modification. The modified starch showed a lower crystallinity and therm...
Article
The objective of this paper was to perform a copolymerization between polyethylene and starch in order to obtain new environmentally friendly materials. The copolymer obtained was characterized thermally, morphologically and structurally, including its pasting profile. The starch-g-PE copolymer showed lower thermal stability compared to the control...
Article
Poly(caprolactone) (PCL) was synthesized from the polymerization of ε-caprolactone (CL) with degraded poly(ethylene terephthalate) (PET) for its functionalization using heptamolybdate of ammonium and tin(II) 2-ethylhexanoate, as catalyst and initiator, respectively. Polymerization of CL with bis(2-hydroxyethyl) terephthalate (BHET) was carried out...
Article
Full-text available
The analysis of materials using Fourier transform infrared (FTIR) spectroscopy has a unique area called the fingerprint region for each compound. However, this area is almost never discussed because of its complexity due to the large number of signals that appear in it. In this work, the fingerprint region analysis of the ethylene-vinyl acetate cop...
Article
α,ω-Hydroxy telechelic poly(ε-caprolactone) (HOPCLOH) was synthesized by ring-opening polymerization (ROP) of ε-caprolactone (ε-CL).The ROP was catalyzed by ammonium decamolybdate in the presence of ether diols [HO-(CH2-CH2-O)m-H] (where m = 2, 3, 4, 5, 6, and 8) as initiators. The homopolymer HOPCLOH was obtained with the ether group (EG) [HO-PCL-...
Article
Full-text available
Starch-g-PCL films were prepared using the casting method and were characterized by different instrumental techniques and physicochemical properties. Nuclear magnetic resonance and Fourier transform infrared spectroscopy led to the proposal of a chemical structure for the films. The Scanning electron micrographs (SEM) of the films showed the format...
Article
The degradation of poly(ethylene terephthalate) by ethylene carbonate with potassium hydroxide was studied. Model reactions were carried out to determine the chemical species produced. Ethylene carbonate reacted with potassium hydroxide to yield oligomers with a limited content of carbonate groups. Bis(2-hydroxyethyl) terephthalate condensed to PET...
Article
Multi-objective optimization was used to evaluate the effect of adding banana (Musa paradisiaca L.) starch and natural rubber (cis-1,4-poliisopreno) at different ratios (1 to 13 w/w) to the manufacturing process of biodegradable films, specifically the effect on the biodegradability, crystallinity and moisture of the films. A structural characteriz...
Article
Full-text available
The chemical modification of physiologically immature banana (Musa paradisiaca L.) was performed via the in situ polymerization of ϵ-caprolactone (CL) utilizing ammonium decamolybdate as a catalyst to obtain a starch-g-PCL copolymer in one step. The copolymerization conditions were studied by varying the CL/catalyst mass ratio, the reaction tempera...
Article
The synthesis of the graft copolymer starch-g-PCL was carried out in a single phase, using molybdenum oxide as a catalyst, at a temperature of 150°C over a period of 24h. Infrared spectroscopy and nuclear magnetic resonance analyses indicated that the graft copolymer was successfully synthesized, obtaining an 84% conversion yield. The introduction...
Article
Full-text available
Oxígeno bueno, oxígeno malo y antioxidantes Muchos elementos de la naturaleza tienen influencia sobre nuestro metabolismo y, en consecuencia, en la preservación de la vida. El oxí-geno constituye uno de los mejores ejemplos, ya que es un elemento indispensable para los seres vivos. Sin embargo, éste puede generar, bajo ciertas condiciones, especies...
Article
Full-text available
The thermal behavior and structural of banana starch films with degraded PET is discussed (S/PETdeg). The PET degradation and the characteristics of A/PETdeg films were analyzed by Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD) and simultaneous thermal analysis (STA). Terephthalic acid, acid dimers and residual macromolec...
Article
Full-text available
The thermal behavior and structural of banana starch films with degraded PET is discussed (S/PETdeg). The PET degradation and the characteristics of A/PETdeg films were analyzed by Fourier transformed infrared spectroscopy (FTIR), X-ray diffraction (XRD) and simultaneous thermal analysis (STA). Terephthalic acid, acid dimers and residual macromolec...
Article
Full-text available
The effect of lintnerization on the banana starch of the Roatán cultivar from acid hydrolysis at 3, 5, and 7 days on the starch digestibility and morphological and thermal features was evaluated. Acid treatment produced an increase in the rapidly digestible starch (RDS) (20.2%) and slowly digestible starch (29.7%), but a decrease in the resistant s...
Article
Full-text available
Nowadays, the tyre is one of the essential materials for transportation, communication and development of societies. For this reason, a large quantity of tyres is produced each year, Due to use, tyres wear out and need to be replaced by new ones. One of the concerns of humanity is searching for applications for wasted tyres, since the vast majority...
Article
Full-text available
Al hablar de materias como química o física, a estudiantes de educación media básica y media superior, pareciera que la mayoría de ellos sufriera un bloqueo mental y el impulso de evadirlas o, francamente, no cursarlas. Es evidente que estas ciencias se consideran duras, y nos da la impresión de que la mayoría de los alumnos preferiría enfrentarse...
Article
Full-text available
Trifluoroacetic anhydride (TFAA) and asymmetric telechelic α-hydroxyl-ω-(carboxyl acid) poly(ϵ-caprolactone) (HA-PCL) were used to obtain in situ α-trifluoroacetate-ω-trifluoroacetanhydride poly(ϵ-caprolactone) (TF-PCL). After reaction, the polymer was characterized by 1H and 13C NMR, MALDI-TOF, FT-IR, DSC, and TGA. Under the influence of TF-PCL an...
Article
Full-text available
In this work the degradation of poly(ethylene terephthalate) was analyzed by varying the temperature and the concentration of potassium hydroxide in 1-butanol holding constant the size and weight of the sample. The temperature range used was from 110oC to 150oC and concentrations of potassium hydroxide in 1-butanol in the range of 0,4 to 4,4 molar,...
Article
Full-text available
En este trabajo se analizó la degradación del poli(etilen tereftalato) variando la temperatura y la concentración de hidróxido de potasio en 1-butanol, manteniendo constante el tamaño y peso de la muestra. El intervalo de temperatura utilizada fue de 110 oC a 150 oC y las concentraciones de hidróxido de potasio en 1-butanol en el intervalo 0,4 a 4,...
Article
The aim of this work is the kinetic and thermodynamic study (by differential scanning calorimetry (DSC) and proton nuclear magnetic resonance (1H-NMR)) of the polymerization of ε-caprolactone initiated by ammonium decamolybdate. By means of isothermal kinetics, enthalpies of reaction in the range 150–160°C, as well as constant rates of polymerizati...
Article
Poly(ethylene-b-ε-caprolactone) (PE-b-PCL) diblock copolymers were synthesized by ring-opening polymerization (ROP) of ε-caprolactone (CL) with α-hydroxyl-ω-methyl polyethylene (PE-OH) as a macroinitiator and ammonium decamolybdate (NH4)8[Mo10O34] as a catalyst. Polymerization was conducted in bulk (130–150°C) with high yield (87–97%). Block copoly...

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