Isocyanate-rich cellulose nanocrystals and their selective insertion in elastomeric polyurethane

Rueda, Lorena; d’Arlas, Borja Fernández; Zhou, Qi; Berglund, Lars A.; Corcuera, María Ángeles; Mondragón, Iñaki; Eceiza, Arantxa

doi:10.1016/j.compscitech.2011.09.014

Cited by 96 publications

(74 citation statements)

References 25 publications

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“…Composites with functionalizated whiskers exhibit an important decrease in  b , which can be related to preferential interaction of HDI anchored chains with hard segment. It results in hard segments crystallization, offering good modulus and retaining a ductile behaviour [5]. Table 2: Tensile test results for neat polyurethane and the processed VC nanocomposites including functionalizated and nonfunctionalizated whiskers.…”

Section: Stpue/vc Whiskersmentioning

confidence: 99%

“…Nanocomposites based on isocyanate-rich vegetal cellulose whiskers and their selective insertion in elastomeric polyurethane has been developed [5]. Nanoreinforcements have been functionalized by means of chemical reaction between the exposed hydroxyl functionalities on whiskers and isocyanate groups from an aliphatic diisocyanate, 1, 6 -hexamethylene diisocyanate (HDI).…”

Section: Pur/vc Whiskersmentioning

confidence: 99%

“…Differential scanning calorimetry (DSC) scans were recorded on a Mettler Toledo 822e instrument, scanning samples from -60 ºC to 150 ºC at 10 ºC/min under nitrogen atmosphere. Dynamic mechanical analysis (DMA) was carried out in tensile mode (DMA Q-800, TA Instruments), applying a constant frequency of 1 Hz, amplitude of 25 m, a temperature range from -90 ºC to 120 ºC, a heating rate of 3 ºC/min and a preload of 0.01 N. Tensile tests were performed using an Insight 10 MTS universal machine with a load cell of 250 N at a crosshead speed of 100 mm/min, according to ASTM D 1708 standard [5].…”

Section: Pur/vc Whiskersmentioning

confidence: 99%

“…These properties have contributed to the use of cellulose as a potential reinforcement due to the combination of their high surface area, high aspect ratio, and exceptional specific mechanical properties [5].…”

Section: Introductionmentioning

confidence: 99%

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Nanostructured composite materials reinforced with nature-based cellulose nanofibres

Vargas

Trifol

Algar

et al. 2012

WIT Transactions on Ecology and the Environment

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A better understanding of the relation between structure and function of cellulose-based hierarchical materials could provide the opportunity for developing new multi-functional composite materials and for designing nanostructured materials structurally optimised, by using biodegradable renewable reinforcing materials.In this paper, recent advances in our Group relating to the study of nanocomposites reinforced with natural cellulose nano-entities, from both vegetal and bacterial sources, are presented. Extraction process of cellulose nanofibres and whiskers as well as composite manufacturing process is expounded. Two composite systems are considered: one based on vegetal cellulose whiskers and another based on bacterial cellulose nanofibres. Presented results are related with morphology, thermal behaviour, mechanical properties, and optical performance of those hierarchical nanocomposites.

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Section: Stpue/vc Whiskersmentioning

confidence: 99%

Section: Pur/vc Whiskersmentioning

confidence: 99%

Section: Pur/vc Whiskersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Nanostructured composite materials reinforced with nature-based cellulose nanofibres

Vargas

Trifol

Algar

et al. 2012

WIT Transactions on Ecology and the Environment

Self Cite

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“…For example, too much stiffening and a concomitant loss of resilience are not desirable for these TPU thermoplastic elastomers. Several studies have been performed on polyurethane host systems by introducing microfibrillated cellulose (MFC) 173,201 , microcrystalline cellulose (MCC) 201 and cellulose nanocrystals (CNC) 195,[201][202][203][204][205] . The cellulose nano/microfibrils can improve the ultimate mechanical properties of the polyurethane nanocomposites.…”

Section: Nanocellulose Reinforced Compositesmentioning

confidence: 99%

Exploring spinifex biomass for renewable materials building blocks

Amiralian¹

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Triodia pungens is one of the 69 species of an Australian native arid grass spinifex which covers approximately 27 % (2.1 million km 2 ) of the Australian landmass. The use of fibrous and resinous components of spinifex has been well documented in traditional indigenous Australian culture for thousands of years. In this thesis the utility of both the cellulosic and resinous components of this abundant biomass for modern applications, and a potential economy for ourAboriginal collaborators, were explored. One part of this study was focused on the optimisation of a resin extraction process using solvent, and the subsequent evaluation, via a field trial, of the potential use and efficacy of the resin as a termiticide. Termiticidal performance was evaluated by re-dissolving the extracted resin in acetone and coating on pine timber blocks. The resin-coated and control blocks (uncoated timber) were then exposed to a colony of Mastotermes darwiniensis termites, which are the most primitive active and destructive species in subterranean areas, at a trial site in northeast Australia, for six months. The results clearly showed that spinifex resin effectively protected the timber from termite attack, while the uncoated control samples were extensively damaged. By demonstrating an enhanced termite resistance, it is shown that plant resins that are produced by arid/semi-arid grasses could be potentially used as treatments to prevent termite attack.In the other part of this study it has been demonstrated that very small diameter and unprecedentedly high aspect ratio cellulose nanofibrils (NFC) can be readily isolated from spinifex biomass using unrivalled mild pulping coupled with minimal mechanical energy by any of three methods; high pressure homogenizer, ultrasonication, and milling. After washing, delignification and bleaching steps, the mechanical defibrillation of fibres was optimized by varying the specific processing conditions of each of these three mechanical treatment methods. Cellulose nanofibres with an extremely low average diameter (below 10 nm) and high aspect ratio (~500) were produced, even after applying very low energy processing. Similarly, acid hydrolysis at lower temperatures and acid concentrations with respect to the published contemporary protocols yielded high aspect ratio cellulose nanocrystals (CNC), for which the average lengths were found to be unaffected by further ultrasonic treatments. We hypothesize that the chemical and morphological origins for this surprisingly low energy input requirement for isolating high aspect ratio nanofibers from Triodia pungens is directly related to the plant's unique morphology and composition, which contains unusually high amounts of hemicellulose. It is also hypothesised that these unique traits are a result of this species' evolution, which has been heavily influenced by an extreme semi-arid climate.Polyurethane and spinifex CNC nanocomposites were also prepared via twin-screw reactive extrusion and solvent casting. Twin-screw reactive extrusion offer...

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Chemical Modification of Nanocelluloses

Habibi¹

2013

Biopolymer Nanocomposites

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Isocyanate-rich cellulose nanocrystals and their selective insertion in elastomeric polyurethane

Cited by 96 publications

References 25 publications

Nanostructured composite materials reinforced with nature-based cellulose nanofibres

Nanostructured composite materials reinforced with nature-based cellulose nanofibres

Exploring spinifex biomass for renewable materials building blocks

Chemical Modification of Nanocelluloses

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