New biphasic mono-component composite material obtained by partial oxypropylation of bacterial cellulose

Rosa, Joyce Rover; Silva, Ingrid Souza Vieira da; Lima, Caroline Stefany Marques de; Neto, Wilson Pires Flauzino; Silvério, Hudson Alves; Santos, Daniele B.; Barud, Hernane da Silva; Ribeiro, Sidney J. L.; Pasquini, Daniel

doi:10.1007/s10570-014-0169-7

Cited by 7 publications

(5 citation statements)

References 23 publications

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“…The DTG diagram of the original BC shows a three-step decomposition process: the first step was up to about 150 • C and was attributed to the release of free and bound water and the main degradation step including depolymerization, dehydration, and decomposition of the cyclic structures [37] was observed from about 200 to 400 • C. In this main decomposition stage, about 75% of the mass of the original BC was lost. The shoulder observed on the right side of the main peak corresponds to the pyrolysis of cellulose [39]. The charred residue obtained from the original BC was 15%.…”

Section: Caracterization Of Bc-phbv Nanocompositesmentioning

confidence: 94%

Surface Treatment of Bacterial Cellulose in Mild, Eco-Friendly Conditions

et al. 2018

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Bacterial cellulose (BC) with increased hydrophobicity is required for several applications including packaging. Surface functionalization of BC may provide good resistance to moisture, increased barrier properties or improved compatibility to polymer matrices. For this purpose, chemical grafting of BC in mild, eco-friendly conditions was carried out using different agents. BC membranes were surface functionalized with vinyl-triethoxy silane (VS) or 3-aminopropyl triethoxysilane (APS), by acylation and acrylation. The efficiency of the surface treatments was highlighted by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, by contact angle measurements and by dynamic mechanical analysis. The morphological investigation by atomic force microscopy and scanning electron microscopy revealed an increased compactness for surface functionalized BC, which correlated well with the different increase of the contact angle. BC treated with APS and VS showed more than a twofold increase in contact angle value. Similarly, the crystallinity degree was reduced to 69.6% and 72.9% after APS and VS treatments as compared with 84.1% for untreated BC, confirming the grafting reaction and the decrease in hydrogen bonding. All the applied treatments delayed the degradation of BC. However, the highest increase in thermal stability was observed for silanes treated membranes. Effective, eco-friendly methods for improving the surface hydrophobicity of bacterial cellulose for food packaging were proposed in this study.

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Section: Caracterization Of Bc-phbv Nanocompositesmentioning

confidence: 94%

Surface Treatment of Bacterial Cellulose in Mild, Eco-Friendly Conditions

et al. 2018

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“…One strategy is the use of the oxypropylation process to obtain polyols, both liquid (total oxypropylation) or biphasic (partial oxypropylation). These polyols can be used to produce polyurethanes and polyesters (Bernardini et al, 2015;Cateto et al, 2013) and onesource composites, (De Menezes et al, 2007;Rosa et al, 2014), respectively.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the oxypropylation process of a lignocellulosic material, almond shell, using the response surface methodology (RSM)

Pinto

Prieto

Ferreira

et al. 2020

Industrial Crops and Products

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Developing polyols from abundant and renewable biomass resources is an important topic for polymer synthesis. In this work, the Response Surface Methodology (RSM) was applied to a novel oxypropylation case study, almond shell (AS), an agroindustry lignocellulosic by-product. Mathematical models were developed to determine responses maximizing the reaction efficiency to yield polyols with specific technical requirements (polyols suitable for rigid polyurethane foams; hydroxyl index between 300 and 800 mgKOH/g, and viscosity below 300 Pa*s). In a general way, the properties of the obtained polyols were within the range of the ones currently used commercially, reinforcing the interest to exploit lignocellulosic bio-residues for polyol synthesis. For simultaneous minimization of homopolymer content and unreacted biomass, values of 14.0% and 14.1% were achieved, respectively. This was attained using a formulation with an AS/PO ratio of 20.1/79.9 g/ml and a catalyst content of 3.14%, giving rise to a polyol with an hydroxyl index of 392.1 KOH/g and a viscosity of 107.4 Pa*s. Overall, the advantages of using RSM to better understand complex reactive systems and the interest to use these statistical approaches as decision-making tools was demonstrated.

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“…TOnset ) SH 269 308 50 432 464 47 3 SHP 126 175 53 294 -36 11 SHBM 242 291 56 559 -30 14 cellulose (Rosa et al, 2014). The third stage of degradation is related to carbonization of the samples, and for all samples this stage lasted until 600 • C. It was verified that the degradation temperature of the biphasic monocomponent residue (SHBM) was close to the temperature of degradation of SH, which proves that the structure of the SH was maintained and the modification occurred only on its surface, while the degradation temperature of the viscous polyol (SHP) was lower than that of SH.…”

Section: Samplesmentioning

confidence: 99%

“…This layer would act as a thermoplastic matrix and the substrate as reinforcement in the preparation of self-reinforced composites, just by simple thermopressing De Menezes et al, 2009a,b;Rosa et al, 2014). The resulting modified substrates are composed of both matrix and reinforcing agent linked by covalent bonds and, as a consequence, can be called a biphasic mono-component.…”

Section: Introductionmentioning

confidence: 99%