Rheology and thermal degradation of isocyanate-functionalized methyl cellulose-based oleogels

Gallego, Rocío; Arteaga, Jesús F.; Valencia, C.; Franco, J.M.

doi:10.1016/j.carbpol.2013.04.104

Cited by 49 publications

(36 citation statements)

References 48 publications

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“…Oleogelators are recognized as anhydrous, self-standing, thermo-reversible, viscoelastic materials structured by a three-dimensional supramolecular network of self-assembled molecules 6,8 .…”

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confidence: 99%

Nutritional Evaluation of Oleogel Made from Micronutrient Rich Edible Oils

et al. 2017

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confidence: 99%

Nutritional Evaluation of Oleogel Made from Micronutrient Rich Edible Oils

et al. 2017

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“…Rheological data collected in Figure 4a,b correspond to oleogels 1 and 4 months aged, respectively. As previously reported for NCO-functionalized methyl cellulose-based oleogels [42], these chemical gels require a certain ageing time to obtain stable rheological properties. Figure 6 shows the evolution of the linear viscoelastic functions with frequency, as a function of ageing time, for selected chitosan- (CSAN-3-25) and chitin-(CTIN-1-30) based oleogels.…”

Section: Rheology Of Chitosan-and Chitin-based Oleogelsmentioning

confidence: 58%

“…As mentioned above, only in the case of chitosan-based oleogels a high degree of functionalization makes possible to reach values of the viscoelastic moduli higher than those displayed by the non-functionalized biopolymer-based oleogel. However, as previously reported [27,42], it must be remarked that these physically stabilized gels present some limitations regarding their physical and mechanical stability, which can be overcome by mean of functionalization. , for NCO-functionalized chitosan-and chitin-based oleogels.…”

Section: Rheology Of Chitosan-and Chitin-based Oleogelsmentioning

confidence: 84%

“…For instance, some limitations regarding physical and mechanical stabilities and thermo-rheological behaviour of previously mentioned cellulosic derivatives-based gel-like dispersions [27][28][29] were pointed out as a consequence of a certain degree of chemical incompatibility between oil and such polar biopolymers. Most of these problems can be overcome by inducing the formation of chemical gels, for instance by dispersing reactive isocyanate-functionalized methylcellulose in the vegetable oil medium [41,42]. Following the same procedure and based on some preliminary studies [43], the possibility of using NCO-functionalized chitin and chitosan to chemically gel castor oil is explored in this work.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Functionalization Degree on the Rheological Properties of Isocyanate-Functionalized Chitin- and Chitosan-Based Chemical Oleogels for Lubricant Applications

et al. 2014

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This work deals with the influence of functionalization degree on the thermogravimetric and rheological behaviour of NCO-functionalized chitosan-and chitin-based oleogels. Chitosan and chitin were functionalized using different proportions of 1,6-hexamethylene diisocyanate (HMDI) and subsequently dispersed in castor oil to promote the chemical reaction between the -NCO group of the modified biopolymer and the -OH group located in the ricinoleic fatty acid chain of castor oil, thus resulting in different oleogels with specific thermogravimetric and rheological characteristics. Biopolymers and oleogels were characterized through Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Small-amplitude oscillatory shear (SAOS) measurements were performed on the oleogels. Oleogels presented suitable thermal resistance, despite the fact that the inclusion of HMDI moieties in the polymer structure led to a reduction in the onset temperature of thermal degradation. The insertion of low amounts of HMDI in both chitin and chitosan produces a drastic reduction in the values of oleogel viscoelastic functions but, above a critical threshold, they increase with OPEN ACCESSPolymers 2014, 6 1930 the functionalization degree so that isocyanate functionalization results in a chemical tool to modulate oleogel rheological response. Several NCO-functionalized chitosan-and chitin-based oleogel formulations present suitable thermal resistance and rheological characteristics to be proposed as bio-based alternatives to traditional lubricating greases.

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“…However, some weaknesses mainly regarding physical and mechanical stabilities were pointed out. Aiming to improve the affinity of cellulosic materials by vegetable oils, the so called "solvency" in the lubricant industry, two different approaches were followed later on: on one hand, the functionalization with non-polar groups in order to reduce the polarity (Martín-Alfonso et al, 2009a, 2011 and, on the other hand, the functionalization of cellulosic derivatives with reactive isocyanate groups able to chemically interact with triacylglycerides (Gallego et al, 2013a(Gallego et al, , 2013b, resulting promising formulations. As a continuation of this investigation, the effect of biopolymer polarity, once functionalized with reactive isocyanate groups, has been explored in this work by evaluating the ability of several commercially available cellulosic derivatives differing in substituents and substitution degree to thicken castor oil.…”

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confidence: 99%