scholarly journals Biodegradable Oligoesters of ε-Caprolactone and 5-Hydroxymethyl-2-Furancarboxylic Acid Synthesized by Immobilized Lipases

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1402 ◽  
Author(s):  
Todea ◽  
Bîtcan ◽  
Aparaschivei ◽  
Păușescu ◽  
Badea ◽  
...  

Following the latest developments, bio-based polyesters, obtained from renewable raw materials, mainly carbohydrates, can be competitive for the fossil-based equivalents in various industries. In particular, the furan containing monomers are valuable alternatives for the synthesis of various new biomaterials, applicable in food additive, pharmaceutical and medical field. The utilization of lipases as biocatalysts for the synthesis of such polymeric compounds can overcome the disadvantages of high temperatures and metal catalysts, used by the chemical route. In this work, the enzymatic synthesis of new copolymers of ε-caprolactone and 5-hydroxymethyl-2-furancarboxylic acid has been investigated, using commercially available immobilized lipases from Candida antarctica B. The reactions were carried out in solvent-less systems, at temperatures up to 80 °C. The structural analysis by MALDI TOF-MS, NMR, and FT-IR spectroscopy confirmed the formation of cyclic and linear oligoesters, with maximal polymerization degree of 24 and narrow molecular weight distribution (dispersity about 1.1). The operational stability of the biocatalyst was explored during several reuses, while thermal analysis (TG and DSC) indicated a lower thermal stability and higher melting point of the new products, compared to the poly(ε-caprolactone) homopolymer. The presence of the heterocyclic structure in the polymeric chain has promoted both the lipase-catalyzed degradation and the microbial degradation. Although, poly(ε-caprolactone) is a valuable biocompatible polymer with important therapeutic applications, some drawbacks such as low hydrophilicity, low melting point, and relatively slow biodegradability impeded its extensive utilization. In this regard the newly synthesized furan-based oligoesters could represent a “green” improvement route.

2013 ◽  
Vol 10 (3) ◽  
pp. 673-685
Author(s):  
Baghdad Science Journal

In this reserch Some new substituted and unsubstituted poly imides compounds. were synthesized by reaction of acrylol chloride with different amides (aliphatic and aromatic) in a suitable solvent in the presence amount triethyl amine (Et3N) with heating. The Structure confirmation of all polymers were confirmed using FT-IR,1H-NMR,13C-NMR and UV spectroscopy. Thermal analysis (TG) for some polymers showed their thermal stabilities. Other physical properties including softening points, melting point and solubility of the polymers were also measured


2014 ◽  
Vol 11 (4) ◽  
pp. 1567-1576
Author(s):  
Baghdad Science Journal

The present work involved synthesis of several new N-Sulfamethoxazol derivatives imide on Polymeric chain by two steps. The first stip involved preparation of N- (sub.orunsub benzoyl and sub unsub acetyl) amidyl sub sulfamethoxazole (1-5) by condensation of sulfamethoxazole drug with many substituted acid chloride, then the second step include, preparation new five N-(acrly-N–sub or unsub benzoyl) imidyl substituted sulfamethoxazol(6-10) by reaction of poly acryloyl chloride with the prepared compound (1-5) in first stepin asuitable solvent in the presenceamount triethylamine (Et3N) with heating. The structure confirmations of all polymers wereconfirmed using FT-IR,1H-NMR,13C-NMR and UV spectroscopy. Other physical properties including softeningpoint's, melting point, and solubility of the polymers were also measured.


2014 ◽  
Vol 775-776 ◽  
pp. 351-356 ◽  
Author(s):  
Luiz Gustavo Ferraro ◽  
Felipe Bastos de Souza Alvarenga ◽  
Maria Virginia Gelfuso ◽  
Daniel Thomazini

. Polymeric materials based on petroleum have generated a major problem for the environment because they are produced by non-renewable sources. Many studies are being conducted to propose alternatives to obtain polymers from renewable raw materials sources. The disadvantage of this alternative is the use of food sources for polymer production but this is avoided when using the residual frying oil. Aiming to obtain polymer-based urethanes, pretreated residual frying oil samples were submitted to various conditions of hydroxylation and analyzed by FT-IR, where it was possible to observe the presence of-OH groups. To optimize the process of hydroxylation a new research was conducted to determine the concentrations of formic acid and hydrogen peroxide that can generate polyols with high levels of hydroxylation index, suitable for the formation of urethanes.


Food Research ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 404-409
Author(s):  
S. Winarti ◽  
U. Sarofa ◽  
M.Y.R. Prihardi

Gelatin is derived from the hydrolysis of the animal collagen contained in the bones and skin. Milkfish bones have the potential to be used as raw materials for gelatine production because it is estimated to be 15–20% of the total body weight of the fish. The extraction of gelatine from fish bones is a solution in utilizing the waste of the fish processing industry. Hydrolysis or soaking in an acidic solution against collagen is aimed to eliminate the salt of calcium and other minerals in the cartilage. This research was conducted to determine the influence of acid types and concentration on the milkfish bones gelatine production. This study used a completely randomized factorial design with two factors. The first factor was the type of acid (citric acid, acetic acid, and a mixture of citric and acetic acids), while the second factor was the concentration of acid (5%, 9%, and 13%). The data obtained were analysed using Analysis of Variance (ANOVA) and Duncan Multiple Range Test (DMRT) Advanced test. The results showed that the type and concentration of acid affected the yield, gel strength, viscosity, melting point, and gelling point. The best treatment in this study was extraction using a 9% concentration of citric acid to produce gelatine with a yield of 10.48%, gel strength 283.1 g bloom, viscosity 4.35 cP, melting point 60.1°C, gel point 16.9°C. Identification of gelatine functional groups was carried out on gelatine from the best treatment using FT-IR Spectrophotometer. From the results of FT-IR spectra analysis, it is known that the functional groups present in the sample are – OH, C-O, N-H, C-H, C-N, C=O which are the main functional groups of gelatine. This study showed that the type and concentration of acid affected the characteristics of milkfish bone gelatine


2015 ◽  
Vol 7 (2) ◽  
pp. 209-216
Author(s):  
S. Nikolaeva ◽  
J.J Saavedra-Arias ◽  
G. Sáenz-Arce ◽  
R. Salas ◽  
J. Vega Baudrit ◽  
...  

Costa Rica has extensive areas of tropical forests that, managed with care and knowledge, can provide renewable raw materials and conserve biodiversity. Here we characterize the branches, leaves and bark of the “Mora Tree”, Maclura tinctoria. We manufactured composite polymeric materials and applied infrared spectrometry, liquid chromatography, optical microscopy, and the analysis of thermal and mechanical properties. We found polyphenols in all parts of the tree. The natural substrate increases crystallization temperature and reduces the crystallinity of low density polyethylene (LDPE). The elasticity modulus is higher for the composite material than for the LDPE. The fibers of this species are a promissing alternative for new products and to reduce the environmental impact of traditional polymeric materials.


e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Jian-Feng Ban ◽  
Shao-Rong Lu ◽  
Chenxi Zhang ◽  
Ting Liu ◽  
Zhiyi Huang

AbstractA series of novel thermotropic liquid crystalline was synthesized from bi(p-hydroxyl benzoic acid)hydroquinone ester (PHQ), triethylene glycol and 2,4- toluenediisocyanate (2,4-TDI) by altering the molar ratio of PHQ and diol, and PHQ was prepared by using hydroquinone and p-hydroxybenzoic acid as raw materials. The thermotropic mesophase behavior, the melting point temperature (Tm) and the isotropization temperature (Ti) of the synthesized polyurethanes were characterized by FT-IR, DSC and POM. It showed that all of the polyurethane polymers exhibited nematic textures at temperature of 110~230 °C. The shift of the melting and isotropization temperature (Tm, Ti) to lower temperature is discussed to be a consequence of the increasing amount of diol content.


2020 ◽  
pp. 48-55
Author(s):  
M.E. Sharanda ◽  
◽  
E.A. Bondarenko ◽  

Ethylene glycol and propylene glycol are important representatives of polyols. On an industrial scale, they are obtained from petrochemical raw materials. Within a decade, significant efforts were made for the producing of polyols from biologically renewable raw materials - carbohydrates. The general trend for carbohydrate hydrogenolysis includes application of liquid-phase process with the use of modified metal-oxide catalysts, at 120-120 ° C and pressure of 3MPa or above. So high pressure is used for the reason to increase hydrogen solubility, and also due to the high partial pressure of low boiling solvents. We supposed that usage of high boiling solvents could allow hydrogenolysis to be performed at the lower pressure. Ethylene glycol and propylene glycol are of particular interest as such kind of solvent since they are both the main products of glucose hydrogenolysis. In this work, the process of hydrogenolysis of glucose and fructose over Cu / MgO-ZrO2 catalyst have been studied at temperature range of 160-200 °C and a pressure of 0.1-0.3 MPa in a flow reactor. The solvents were simultaneously the target products of the reaction - ethylene glycol and / or propylene glycol. Gas chromatography and 13C NMR were used for the reaction products identification. It was found that the solubility of glucose in propylene glycol is 21 % by weight, and in ethylene glycol 62% by weight. It was pointed out that the process of hydrogenolysis can take place at a pressure close to atmospheric. Under these conditions, the conversion of hexoses reaches 96-100 %. The reaction products are preferably propylene glycol and ethylene glycol. The total selectivity for C3-2 polyols is 90-94 %, that is higher than in the hydrogenolysis of glucose in aqueous solution.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3474
Author(s):  
Katarzyna Uram ◽  
Milena Leszczyńska ◽  
Aleksander Prociak ◽  
Anna Czajka ◽  
Michał Gloc ◽  
...  

Rigid polyurethane foams were obtained using two types of renewable raw materials: bio-polyols and a cellulose filler (ARBOCEL® P 4000 X, JRS Rettenmaier, Rosenberg, Germany). A polyurethane system containing 40 wt.% of rapeseed oil-based polyols was modified with the cellulose filler in amounts of 1, 2, and 3 php (per hundred polyols). The cellulose was incorporated into the polyol premix as filler dispersion in a petrochemical polyol made using calenders. The cellulose filler was examined in terms of the degree of crystallinity using the powder X-ray diffraction PXRD -and the presence of bonds by means of the fourier transform infrared spectroscopy FT-IR. It was found that the addition of the cellulose filler increased the number of cells in the foams in both cross-sections—parallel and perpendicular to the direction of the foam growth—while reducing the sizes of those cells. Additionally, the foams had closed cell contents of more than 90% and initial thermal conductivity coefficients of 24.8 mW/m∙K. The insulation materials were dimensionally stable, especially at temperatures close to 0 °C, which qualifies them for use as insulation at low temperatures.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1411
Author(s):  
José Luis P. Calle ◽  
Marta Ferreiro-González ◽  
Ana Ruiz-Rodríguez ◽  
Gerardo F. Barbero ◽  
José Á. Álvarez ◽  
...  

Sherry wine vinegar is a Spanish gourmet product under Protected Designation of Origin (PDO). Before a vinegar can be labeled as Sherry vinegar, the product must meet certain requirements as established by its PDO, which, in this case, means that it has been produced following the traditional solera and criadera ageing system. The quality of the vinegar is determined by many factors such as the raw material, the acetification process or the aging system. For this reason, mainly producers, but also consumers, would benefit from the employment of effective analytical tools that allow precisely determining the origin and quality of vinegar. In the present study, a total of 48 Sherry vinegar samples manufactured from three different starting wines (Palomino Fino, Moscatel, and Pedro Ximénez wine) were analyzed by Fourier-transform infrared (FT-IR) spectroscopy. The spectroscopic data were combined with unsupervised exploratory techniques such as hierarchical cluster analysis (HCA) and principal component analysis (PCA), as well as other nonparametric supervised techniques, namely, support vector machine (SVM) and random forest (RF), for the characterization of the samples. The HCA and PCA results present a clear grouping trend of the vinegar samples according to their raw materials. SVM in combination with leave-one-out cross-validation (LOOCV) successfully classified 100% of the samples, according to the type of wine used for their production. The RF method allowed selecting the most important variables to develop the characteristic fingerprint (“spectralprint”) of the vinegar samples according to their starting wine. Furthermore, the RF model reached 100% accuracy for both LOOCV and out-of-bag (OOB) sets.


2020 ◽  
Vol 164 ◽  
pp. 08031
Author(s):  
Evgeniy Velichko ◽  
Edward Tshovrebov ◽  
Ural Niyazgulov

The article deals with issues of monitoring, planning, organizational and technical support, economic regulation and improving the efficiency of the infrastructure for processing, recycling and disposal of waste, resource conservation and management of secondary resources, their use as secondary raw materials for production, services, work and power generation. The Russian Federation has significant potential for economic growth due to the efficient use of secondary resources from billions of tons of generated production and consumption waste annually. These ecologically unsafe anthropogenic objects can be characterized as a source of valuable renewable raw materials, material and fuel and energy resources. However, the scale and level of use of various types of secondary resources are characterized by considerable unevenness and depend on the demand for secondary raw materials, the resource value of the waste, the environmental situation arising from treating them as environmental polluters, on the real economic conditions that determine the profitability of each specific type. economic activities that use secondary resources for the manufacture of products, works, services, energy production. The methods of monitoring the industry for the treatment, disposal and disposal of waste are: information-analytical, information-statistical, sociological, geo-information. The legal status of the monitoring system of the industry for the treatment, disposal and disposal of waste is determined by the limitations of its functionality within the framework of the goals and objectives facing it.


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