Structure formation of regenerated cellulose materials from NMMO-solutions

https://www.rsc.org/suppdata/gc/b7/b713289a/suprev.pdf

Cellulose dissolution with polar ionic liquids under mild conditions: required factors for anions

The chemistry of side reactions and byproduct formation in the system NMMO/cellulose (Lyocell process)

Natural fibre-based composites have been intensely studied in the last years due to their specific properties and their clearly positive environmental impact. Other advantages of using vegetable fibres are related to their economical production and processing, their safe handling and working conditions. Therefore, lignocellulosic natural fibres constitute an interesting alternative to traditional synthetic fibres in composite materials. This work is intended to present an overview of the main results presented in literature on this topic, focusing the attention on the fibres properties in terms of physical and chemical structure, thermal and mechanical properties. Some aspects related to the production of vegetable fibres for composites are also presented.

A Review on Natural Fibre-Based Composites-Part I

Natural abundance, much higher strength per unit weight than most inorganic fillers, lower density and their biodegradable nature make natural fillers attractive as reinforcements of engineering polymer systems. However, certain drawbacks such as incompatibility with the hydrophobic polymer matrix, the tendency to form aggregates during processing and poor resistance to moisture greatly reduce the potential of natural fibres to be used as reinforcements in polymers. In this review, the main results presented in literature are summarized, focusing on the processing behaviour and final properties of natural fibres with polymeric matrices (thermoplastics, thermosets and biodegradables) and paying attention to the use of physical and chemical treatments for the improvement of fibre-matrix interaction and composite mechanicaln properties. This work mainly focuses on the use of natural fibres for automotive applications.

A Review on Natural Fibre-Based Composites—Part II: Application of Natural Reinforcements in Composite Materials for Automotive Industry

Cellulose mesophases were obtained by preparing concentrated solutions of cellulose (20–55%) in a mixture of N-methyl-morpholine N-oxide (MMNO) and water. The anisotropy depends on four interconnected parameters: the temperature of the solution which, in general, must be lower than 90°C; the concentration of cellulose which must exceed 20%; a water content such that the mole ratio water/anhydrous MMNO is smaller than unity; and the degree of polymerization of the dissolved cellulose. The anisotropic cellulose solutions can readily be oriented during extrusion or casting thus giving fibers or films which upon regeneration exhibit high orientation.

Oriented cellulose films and fibers from a mesophase system

Phase behavior of the quasiternary system N-methylmorpholine-N-oxide, water, and cellulose

Each homopolymer, cellulose and polyamide 66 (PA66), was separately dissolved in a mixture of N-methyl morpholine N-oxide and phenol (80/20 w/w). Then, the two solutions were mixed together. This step leads to the crystallization of PA66 in small aggregates (about 1 μm) regularly dispersed in the cellulose solution. It appeared that this morphology remains independent of further processing such as spinning or casting. Finally, fibers or films were precipitated in methanol. The entire preparation technique used here results mainly in two-phase systems in which PA66 domains are embedded in an amorphous cellulose matrix. The specimens obtained were at first characterized by DSC, SEM, and WAXS

Cellulose‐polyamide 66 blends. I. Processing and characterization

New polymer blends based on cellulose and poly(vinyl pyrrolidone) (PVP) were obtained using a mixture of N=methyl morpholine N-oxide (NMMO) and dimethylsulfoxide (DMSO) as a common solvent system. Materials are obtained after the removing of NMMO-DMSO in three of their different solvents, namely i) H2O, ii) a mixture 95/5 vol/vol hexamethyl phosphororri amide (HMPA) DMSO and iii) a mixture of 95/5 vol/vol dioxan/water.

A. Peguy

Papers

Oriented cellulose films and fibers from a mesophase system

Phase behavior of the quasiternary system N-methylmorpholine-N-oxide, water, and cellulose

Cellulose‐polyamide 66 blends. I. Processing and characterization

Cellulose-poly(vinyl pyrrolidone) blends studied by scanning electron microscopy and dynamic mechanical measurements