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The production of release coatings has been increasing in recent years because of their use in various fields. However, commercially available release coatings are regarded as non-recyclable. As a consequence, the repulping of these residues is difficult, and their presence in the recycling stream represents an important source of contamination. One solution to this problem is to use new coating materials that can replace the siliconized backing, provided that these new materials are recyclable. As a solution to this problem, the authors propose the use of alkylated phosphorylated fibers to produce an environmentally friendly and inexpensive release paper. The results show that a surface application of hydrophobic phosphorylated fibers reduces the surface free energy of the paper support, as well as the peel strength, which facilitates the separation of the adhesive tape. [ABSTRACT FROM AUTHOR]

In this work, phosphorylated cellulosic fibers were functionalized with an aminosilane ((3-aminopropyl)triethoxysilane, APTES) using a simple and economical method. Several characterization were performed to determine the types of bonds between phosphorylated fibers and grafted APTES. The thermal behavior, hydrophobicity and surface charge variation as a function of pH of the multifunctional cellulose fibers were determined. Results demonstrate that APTES should proceed through Si-O-C, and possibly Si-O-P, covalent bonds with cellulose although the dimerization of silane through Si-O-Si bonds has also been observed. The terminal amino groups are expected to be partially involved in hydrogen bonds with phosphate hydroxyl groups found at phosphorylated cellulose fiber surface, causing a pulling in the configuration of the grafted APTES. The two chemical modifications proposed in this work do not significantly modify the morphology of cellulose fibers. XRD analysis also shows that the crystal structure of the phosphorylated fibers did not change after functionalization with APTES. The silylated phosphorylated fibers show potential flame-retardant properties with improved hydrophobicity. Furthermore, the functionalization of phosphorylated fibers with APTES changes the pH of zero charge point from 3.2 to 9.4 and providing a zwitterionic structure suitable for the simultaneous adsorption of both cationic and anionic species. [Display omitted] [ABSTRACT FROM AUTHOR]

Transverse compaction of fibre reinforcements has significant importance in the production of complex dry fibre preforms for the resin transfer moulding (RTM) process of composite materials. This work investigates, for the first time, the planar compaction of phosphorylated stacks of unidirectional (UD) reinforcements made of flax yarns held together by a thin layer of short flax fibres. Planar compaction tests were carried out to evaluate the influence of temperature and humidity on the creep percentage, thickness recovery, and permanent deformation of UD reinforcements prepared with and without phosphorylation. It appears that the creep percentage and permanent deformation are more important for phosphorylated reinforcements than for untreated ones. Increasing the compaction temperature and humidity results in an increase of the creep and permanent deformation of phosphorylated fibres. The tensile strength of phosphorylated fibres‐reinforced composites is lower than that of untreated ones while there is no effect on the tensile modulus. [ABSTRACT FROM AUTHOR]

The properties of phosphorylated kraft fibers, including their flame retardancy and behavior in water, such as electrical charge and swelling capacity, were investigated in this study. Two different phosphorus contents and three forms of phosphorylated fibers (ammonium, acid, and sodium) were analyzed. All types of phosphorylated fibers exhibited high char formation and limiting oxygen index (LOI) values, indicating good flame retardancy. In particular, the ammonium form exhibited the best flame retardancy behavior and the highest LOI value. The charge density and swelling capacity of the kraft fibers were significantly increased by phosphorylation. Alkaline treatment following the phosphorylation reaction further increased the water retention value (WRV) and surface charge of the kraft fibers. Compared to unmodified kraft fibers, the phosphorylated fibers had lower absolute values of the negative zeta potentials, and these values were less affected by conductivity. [ABSTRACT FROM AUTHOR]

Highlights: [•] We present a new synthesis pathway to produce phosphorylated cellulosic fibers. [•] The main phosphorylating reagent is a phosphate ester. [•] Phosphorylated fibers show negligible degradation compared to previous phosphorylation processes. [•] The phosphorus distribution (bulk vs. surface) is presented. [•] The type of phosphate structures found on modified fibers is discussed. [ABSTRACT FROM AUTHOR]