Crosslinking of Epoxidized Natural Rubber with Borax for Self-Healing and Self-Repairing Properties: pH Dependence.

Epoxidized natural rubber (ENR) crosslinked using borax, which exhibits self-healing and self-repairing properties, is successfully developed. The crosslink formation of ENR by using borax under neutral and alkaline conditions is investigated. Fourier transform infrared spectroscopy (FTIR) shows that the borate-ester bond is formed in ENR prepared under both neutral and alkaline conditions, whereas boron nuclear magnetic resonance ( B-NMR) results exhibit that the ENR prepared under alkaline conditions more actively forms crosslink networks with borax.

Development of chitin nanofiber coatings for prolonging shelf life and inhibiting bacterial growth on fresh cucumbers.

The widespread usage of petroleum-based polymers as single-use packaging has had harmful effects on the environment. Herein, we developed sustainable chitin nanofiber (ChNF) coatings that prolong the shelf life of fresh cucumbers and delay the growth of pathogenic bacteria on their surfaces. ChNFs with varying degrees of acetylation were successfully prepared via deacetylation using NaOH with treatment times of 0-480 min and defibrillated using mechanical blending.

Development of water-resistant paper using chitosan and plant-based wax extracted from banana leaves.

On being exposed to water, cellulose paper swells and its mechanical properties become weak. In this study, natural wax with an average particle size of 12.3 μm extracted from banana leaves was mixed with chitosan to prepare coatings applied on paper surfaces.

Property enhancement of epoxidized natural rubber nanocomposites with water hyacinth-extracted cellulose nanofibers.

Cellulose nanofibers (CNFs) have been widely used as reinforcement in various polymer matrices; however, limited studies of the use of CNFs in epoxidized natural rubber (ENR) have been reported. Here, we successfully prepared CNF-reinforced ENR nanocomposites with superior mechanical performance. CNFs were disintegrated from water hyacinth (Eichhornia crassipes) using high-pressure homogenization, and ENR nanocomposites with CNFs were fabricated by initial mixing and hot pressing.

Chitosan coating for the preparation of multilayer coated paper for food-contact packaging: Wettability, mechanical properties, and overall migration.

Cellulose-based paper is an alternative substitution for petroleum-based polymers for packaging applications, but its mechanical performance is poor when in contact with water. Herein, chitosan was applied on cellulose-based paper via a coating approach. The effects of chitosan coatings between none and five layers on the color properties, wettability, thermal properties, mechanical performance, and overall migration in food simulants of the paper were evaluated.

Superabsorbent cellulose-based hydrogels cross-liked with borax.

Cellulose, the most abundant biopolymer on Earth, has been widely attracted owing to availability, intoxicity, and biodegradability. Environmentally friendly hydrogels were successfully prepared from water hyacinth-extracted cellulose using a dissolution approach with sodium hydroxide and urea, and sodium tetraborate decahydrate (borax) was used to generate cross-linking between hydroxyl groups of cellulose chains. The incorporation of borax could provide the superabsorbent feature into the cellulose hydrogels.

Review of the recent developments in all-cellulose nanocomposites: Properties and applications.

Cellulose, the most abundant polysaccharide on Earth, has a number of desirable properties, including availability, biodegradability, low cost, and low toxicity and has been used in a variety of applications. Recently, all-cellulose composite materials have been made from a wide variety of cellulose sources, including wood and agricultural wastes, via impregnation or partial surface dissolution approaches utilizing a specific solvent. Due to the improved interfacial interactions between the cellulose matrix and cellulose reinforcement, all-cellulose composites exhibit superior mechanical properties when compared to biopolymers and petroleum-based polymers.

Surface and Interface Engineering for Nanocellulosic Advanced Materials.

How do trees support their upright massive bodies? The support comes from the incredibly strong and stiff, and highly crystalline nanoscale fibrils of extended cellulose chains, called cellulose nanofibers. Cellulose nanofibers and their crystalline parts-cellulose nanocrystals, collectively nanocelluloses, are therefore the recent hot materials to incorporate in man-made sustainable, environmentally sound, and mechanically strong materials. Nanocelluloses are generally obtained through a top-down process, during or after which the original surface chemistry and interface interactions can be dramatically changed.

Mechanical and antibacterial properties of the chitosan coated cellulose paper for packaging applications: Effects of molecular weight types and concentrations of chitosan.

Chitosan with low (25 kDa) and high molecular weight (2100 kDa) were used to enhance performances of paper made from steam-exploded bamboo fibers and nanofibrillated cellulose. Chitosan solutions with concentrations of 0-1.0 wt% were manually applied on paper surface using a facile coating approach with a wire bar.

Thermally Superstable Cellulosic-Nanorod-Reinforced Transparent Substrates Featuring Microscale Surface Patterns.

The recent rapid expansion of thin-film, bendable, and wearable consumer (opto)electronics demands flexible and transparent substrates other than glass. Plastics are the traditional choice, but they require amelioration because of their thermal instability. Here, we report the successful conversion of a soft and thermally vulnerable polymer into a highly thermally stable transparent nanocomposite material.

Effect of clay content on morphology and processability of electrospun keratin/poly(lactic acid) nanofiber.

This research work has concerned the development of volatile organic compounds (VOCs) removal filters from biomaterials, based on keratin extracted from chicken feather waste and poly(lactic acid) (PLA) (50/50%w/w) blend. Clay (Na-montmorillonite) was also added to the blend solution prior to carrying out an electro-spinning process. The aim of this study was to investigate the effect of clay content on viscosity, conductivity, and morphology of the electrospun fibers.

Effective Young's modulus of bacterial and microfibrillated cellulose fibrils in fibrous networks.

The deformation micromechanics of bacterial cellulose (BC) and microfibrillated cellulose (MFC) networks have been investigated using Raman spectroscopy. The Raman spectra of both BC and MFC networks exhibit a band initially located at ≈ 1095 cm(-1). We have used the intensity of this band as a function of rotation angle of the specimens to study the cellulose fibril orientation in BC and MFC networks.

Micromechanics of TEMPO-oxidized fibrillated cellulose composites.

Composites of poly(lactic) acid (PLA) reinforced with TEMPO-oxidized fibrillated cellulose (TOFC) were prepared to 15, 20, 25, and 30% fiber weight fractions. To aid dispersion and to improve stress transfer, we acetylated the TOFC prior to the fabrication of TOFC-PLA composite films. Raman spectroscopy was employed to study the deformation micromechanics in these systems.