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Plant fibers (PFs), such as hemp, Coir, and straw, are abundant in resources, low in price, light weight, biodegradable, have good adhesion to the matrix, and have a broad prospect as reinforcements. However, the degradation of PFs in the alkaline matrix is one of the main factors that affects the durability of these composites. PFs have good compatibility with cement and the geopolymer matrix. They can induce gel growth of cement-based materials and have a good toughening effect. The water absorption of the hollow structure of the PF can accelerate the degradation of the fiber on the one hand and serve as the inner curing fiber for the continuous hydration of the base material on the other. PF is easily deteriorated in the alkaline matrix, which has a negative effect on composites. The classification and properties of PFs, the bonding mechanism of the interface between PF reinforcements and the matrix, the water absorption of PF, and its compatibility with the matrix were summarized. The degradation of PFs in the alkaline matrix and solution, drying and wetting cycle conditions, and high-temperature conditions were reviewed. Finally, some paths to improve the alkaline degradation of PF reinforcement in the alkaline matrix were proposed. [ABSTRACT FROM AUTHOR]

Polyelectrolyte complex (PEC) hydrogel, formed via physically electrostatic crosslinks between polyanion and polycation, is an interesting hydrogel in terms of its nontoxicity and solvent-free technique. In this work, poly (sodium 4-styrenesulfonate) (PSS)/poly (diallyl dimethyl ammonium chloride) (PDADMAC) complex hydrogels were prepared. Firstly, the PSS/PDADMAC complex aggregates using various PSS/PDADMAC mole fractions that were prepared in the presence of NaCl solution. Then, the aggregates were resolubilized under stirring at 70 °C for 2 h to obtain a homogeneous PEC solution. Finally, the PEC solution was dialyzed using a dialysis membrane with 3500 molecular cut-off for 1 day. The dialysis bath was changed every interval period of 2 h to control the rate of reversible electrostatic interaction, resulting in the homogenous PEC hydrogel with porous morphology as revealed by SEM and BET investigations. The dimensional stability and viscoelasticity of the PEC hydrogel was studied by DMA experiment, which showed the viscoelastic behavior at a compressive force ranging from 0 to 0.1 N. Finally, PSS/PDADMAC hydrogels showed a high water absorbency property and excellent affinity to textile anionic dyes. [ABSTRACT FROM AUTHOR]

The furnish management of tissue materials is fundamental to obtain maximum quality products with a minimum cost. The key fiber properties and fiber modification process steps have a significant influence on the structural and functional properties of tissue paper. In this work, two types of additives, a commercial biopolymer additive (CBA) that replaces the traditional cationic starch and micro/nanofibrillated cellulose (CMF), were investigated. Different formulations were prepared containing eucalyptus fibers and softwood fibers treated mechanically and enzymatically and both pulps with these two additives incorporated independently and simultaneously with drainage in the tissue process range. The use of these additives to reduce the percentage of softwood fibers on tissue furnish formulations was investigated. The results indicated that a maximum of tensile strength was obtained with a combination of both additives at the expense of softness and water absorbency. With a reduction of softwood fibers, the incorporation of additives increased the tensile strength and water absorbency with a slight decrease in HF softness compared with a typical industrial furnish. Additionally, a tissue computational simulator was also used to predict the influence of these additives on the final end-use properties. Both additives proved to be a suitable alternative to reduce softwood fibers in the production of tissue products, enhancing softness, strength and absorption properties. [ABSTRACT FROM AUTHOR]