Synthesis of new carbohydrate-based polyurethanes and their application in the purification of methyl esters (biodiesel)

Kubota, Tatiana; Araújo, Márcia Valéria Gaspar de; Vieira, João Victor Francisco; Silva, Thiago Aparecido da; Ramos, Luiz Pereira; Zawadzki, Sônia Faria

doi:10.1007/s10965-012-0048-6

Cited by 8 publications

(3 citation statements)

References 41 publications

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“…Thermal properties of the bulk and nanopolyurethanes (SBPU 2i-7i and SNPU 2i-7i ) 31 – 34 studied by TGA thermograms have shown that the thermal decomposition of starch nanocrystals varies from the starch-based bulk and nanopolyurethanes due to structural changes such as crystallinity and thus confirmed the grafting of the urethane linkages to native structure of SNCs (Fig. 3 ).…”

Section: Resultsmentioning

confidence: 68%

Polyurethane-functionalized starch nanocrystals as anti-tuberculosis drug carrier

Desai

Mondal

Bera

2021

Sci Rep

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Studies related to loading ability and delivery of clinically used first-line anti-tuberculosis drugs (ATDs) such as isoniazid, rifampicin, pyrazinamide and streptomycin on the surface of starch-derived bulk and nanopolyurethanes (SBPUs and SNPUs) as drug delivery systems (DDS) have been focused to minimise or remove the drug-associated adverse effects. The efficiencies of nanopolyurethanes obtained from the differently substituted cyclic aliphatic and aromatic isocyanates have been studied for drug loading and release purposes. Different advanced instrumental techniques analysed the structural and morphological properties, thermal stability and crystallinity of the starch nanopolyurethans. Average particle sizes ranging from 27.35–42.38 nm to 126.89–218.60 nm for starch nanopolyurethans, SNPU3i and SNPU4i, respectively, were determined by high-resolution transmission electron microscopy. Similarly, the loading efficiency of ATDs to the surfaces of SNPUs and SBPUs was observed in the range of 60–97% while ATDs-loaded SNPUs showed a sustainable release profile for all ATDs except for streptomycin. However, most SBPUs provided burst-release for all the above-mentioned ATDs in pH-dependent studies. The anti-tuberculosis assay against the Mycobacterium tuberculosis H37Rv strain revealed that streptomycin-loaded SNPU4i and isoniazid-loaded SNPU7i are approximately 42 and 7 times more active than the native streptomycin and isoniazid, respectively.

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Section: Resultsmentioning

confidence: 68%

Polyurethane-functionalized starch nanocrystals as anti-tuberculosis drug carrier

Desai

Mondal

Bera

2021

Sci Rep

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“…The samples of SNC and their corresponding carbohydrate‐based polyurethanes ( NPU3 – NPU6 ) were analyzed by powder X‐ray diffractometry (P‐XRD) to evaluate the changes occurred in the crystallinity pattern of the SNC as a result of reaction with the different diisocyanates. In Figure , SNC showed four intense X‐ray diffraction peaks predominantly at 15.00, 17.00, 18.00, and 23.00°2θ …”

Section: Resultsmentioning

confidence: 98%

“…Since, the carbohydrate‐based nanopolymer alone might not be sufficient to increase the pore volume for better adsorption but the introduction of carbamate/urethane (–NHCO 2 –) linkages as polycarbamate/polyurethane in the substances generates new physical and mechanical properties, such as porosity, high rigidity, flexibility, hardness, adsorptivity, abrasion resistance, and elasticity. The involvement of adsorbents, that is, polyurethanes, particularly, carbohydrate‐based polyurethanes obtained from chitin, starch, and their derivatives chitosan and cyclodextrins for the purification of biodiesel show great promise by reducing the amount of fuel contaminants such as unreacted glycerides, soaps, and free fatty acids (FFAs) …”

Section: Introductionmentioning

confidence: 99%

Polyurethane‐functionalized starch nanoparticles for the purification of biodiesel

Desai

Bera

Singh

et al. 2016

J of Applied Polymer Sci

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Polyurethane-functionalized starch nanoparticles (PUFSNPs) have been synthesized by chemical modification of polyhydroxylated starch nanocrystals (SNC) with aliphatic and aromatic diisocyanates. The covalent attachment of the diisocyanates to the backbone of SNC for the formation of starch-derived nanopolyurethane polymers was unambiguously determined by FTIR and NMR spectroscopy. PUFSNPs were entirely obtained from SNC with yields ranging from 41.5 to 86.0 wt % and their size distribution, size, porosity and morphology were determined by dynamic light scattering (DLS), high resolution transmission electron microscopy (HRTEM) and Brunauer-Emmett-Teller (BET) adsorption techniques. The size and surface area of the cyclic aliphatic-based PUFSNP (NPU4) is 27 nm and 52.64 m 2 g 21 , respectively, indicating one of the potential and promising biodegradable materials for the adsorption of acid impurities and contaminants that are found in crude biodiesel. The acid content of the biodiesel is remarkably reduced by 32-39% with PUFSNPs while 7-18% with their corresponding bulk materials.

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Preparation of Polyurethane Foams Based on Maltodextrin and Their Potential Use in Methyl Ester (Biodiesel) Purification

Kubota¹,

Araújo²,

Sá³

et al. 2016

Macromolecular Symposia

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Biodiesel can be obtained by transesterification of the triglycerides present in the vegetable oil and animal fat. After the reaction it is necessary to purify the alkyl esters. One way to obtain this is making the dry wash. Thus, this study proposes the preparation of polyurethane foams with maltodextrin as sorbents for use in the biodiesel purification. The foams were prepared and characterized by ATR-FTIR, TGA, DSC and water absorption test (ASTM D570). The FTIR spectra showed typical bands of polyurethane, TGA curves showed weight loss in two stages, the DSC analysis of the foams based on maltodextrin revealed a Tg value higher than that observed for the control foam, moreover, the absorption test in water showed that the foams based on maltodextrin showed a more hydrophilic character. The efficiency of the foams as possible sorbents for biodiesel purification was monitored by two indicators: soap concentration (AOCS Cc 17-19) and acidity index (AOCS Ca 5a-40). The results indicated that the foams were promising candidates in the removal of contaminants.

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Synthesis of new carbohydrate-based polyurethanes and their application in the purification of methyl esters (biodiesel)

Cited by 8 publications

References 41 publications

Polyurethane-functionalized starch nanocrystals as anti-tuberculosis drug carrier

Polyurethane-functionalized starch nanocrystals as anti-tuberculosis drug carrier

Polyurethane‐functionalized starch nanoparticles for the purification of biodiesel

Preparation of Polyurethane Foams Based on Maltodextrin and Their Potential Use in Methyl Ester (Biodiesel) Purification

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