Partial oxypropylation

Sugar beet pulp, Cork, Chitin, Chitosan, Olive pits. Polyurethane foams. Partial oxypropylation. Total oxypropylation. Cellulose fibres. Starch granules. Single-component composites... 

All the above systems require a sequence of steps and the use of solvents to attain the final goal, which complicates the process both in toms of economical and ecological soundness. The direct transformation of cellulose fibres into self-reinforced composites by partial oxypropylation was considered a promising alternative to this working hypothesis since it eliminated the use of solvents and could be conducted in a straightforward one-step operation. The study of this system confirmed its viabOity and produced interesting composite materials [20]. 

Figure 12.8 SEM micrographs of filter paper fibres (a) before, and (b) after partial oxypropylation.

Figure 12.8 SEM micrographs of rayon filaments (c) before and (d) after partial oxypropylation and (e) hot-pressing into a film. (Reproduced by permission of Elsevier. Copyright 2006. Reprinted from Reference [20]).

A different approach was recently applied to cellulose fibres and starch granules to prepare single-component composites by the partial oxypropylation of these substrates. These novel materials are described in Chapter 12. 

We already mentioned in Section 3.5 [70] the partial oxypropylation of cellulose fibres and the interest of the ensuing composite materials in which the unmodified fibre cores represent the reinforcing elements and their thermoplastic sleeves the source of a matrix. Other interesting approaches have been recently put forward to prepare composite materials in which cellulose or one of its derivatives prepared in situ are the only component. Glasser was the first to tackle this problem through the combination of cellulose esters and fibres by two distinct approaches, viz. (i) the incorporation of lyocell fibres into a cellulose acetate matrix [92] and (ii) the partial esterification of wood pulp fibres with -hexanoic anhydride in an organic medium [93] that produced thermally deformable materials in which the thermoplastic cellulose ester constituted the matrix and the unmodified fibres the reinforcing elements. 

Gandini, A., and Belgacem, M.N. (2008) Partial or total oxypropylation of natural polymers and the use of the ensuing materials as composites or polyol macromonomers, in Monomers,... 

Synonyms Cellulose, 2-hydroxypropyl ether HPC Hydroxypropyl ether of cellulose Hyprolose Oxypropylated cellulose Definition Partially substituted poly(hydroxypropyl) ether of cellulose Properties Off-wh. gran, powd., odorless, tasteless sol. in cold water, methanol, ethanol, many polar org. soivs. insol. in water > 37.7 C ... 

PPG-5 lanolin alcohol ether PPG-20 lanolin alcohol ether PPG-2 laurate PPG-2 oleate PPG-2 stearate dispersant, polyelectrolyte 2-Hydroxy 3-methacryl oxypropyl trimoniumchloride dispersant, polymerization C13-15 pareth-30 Polymethacrylic acid Polysorbate 80 Polyvinyl alcohol (partially hydrolyzed) dispersant, polymers... 

Partial or Total Oxypropylation of Natural Polymers, A. Gandini M.N. Belgacem... 

Synonyms Cellulose, 2-hydroxypropyl ether HPC Hydroxypropyl ether of cellulose Hyprolose Oxypropylated cellulose Definition Partially substituted poly(hydroxypropyl) ether of cellulose ionic Nature Nonionic... 

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