Cationic starches applications

Commercially available cationic starches for wet end application are quaternary and tertiary products. These products have been available since about the mid 1950 s and no new basic chemistry has been developed since that time. The development in the late 1940 s and early 1950 s of starch ethers and esters made in the original granule form led to a torrent of starch derivatives for industrial use. Very few of these became commercial. This is possibly because the functions that were required by the industrial and food markets were far... 

Cationic starches have numerous applications in paper industry, in textiles, as flocculating agents, in cosmetics, adhesives, etc. 

Cationic starches, for instance 2-hydroxy-3-trimethylammoniopropyl starch chloride, can be combined with anionic fluorescent whitening agents, such as di-aminostilbenedisulfonate, in order to produce fluorescent starch.2491 Unfortunately, despite their low cost and easy application, cationic starches have little prospect for use as soil stabilizers because of their low activity, which is independent of the metal ions present in the soil.2492... 

Cationic starch is the major wet-end starch. The phenomena involved in starch adsorption and the selection of cationic starch need careful consideration, as do the proper preparation and application of starch. The criteria for the use of native, anionic and amphoteric starches are also considered. 

Anionic trash catchers are either inorganic salts (aluminium, zirconium) or high charged cationic polymers. Extranely high DS, low molecular weight cationic starches are available for use in this application and are found to quench OBAs much less than polymers such as poly-DADMAC or polyacrylamide. 

Derivatized starches are obtained by reaction with a-chloroacids, epoxy derivatives or anhydrides in alkaline conditions. In general, they have lower gelatinization temperature, better film-forming properties and tend to give softer gels. Typical products used in oil drilling fluids, adhesives and paper applications are carboxymethylated starches, hydroxypropylated starches, cationized starches and acetylated starches. 

Besides the naturally occurring cationic PS chitin and chitosan, a huge variety of semi-synthetic products is available, which are based on anchoring cationic groups onto the polysaccharide backbone. Examples include cationic starch and cationic cellulose derivatives, which are widely used for industrial purposes (cationic starch in paper ) and also in medical applications (cationic cellulose as additives, e.g. JR-400 and Quatrisoft LM-200 in hygienic products). However, applications in regenerative medicine are rather poorly developed for these materials and therefore a discussion is excluded at this point. 

This chapter describes the main properties and methods for the characterization of polyelectrolytes derived from the biomass. The most important sources are plants, with cellulose and starch, which turn to polyelectrolytes after chemical modifications. CarboxymethylceUulose is the main cellulose derivative used in many industrial applications as good thickener and hydrophilic polymer for aqueous media. Cationic starches are mainly used in the paper industry for fiUa- retention or paper wet-strength. Natural polyelectrol5des are produced by algae with anionic alginates and carrageenans as the major representatives, which are used in food applications and for biomedical devices. In this respect, alginates are often associated in an electrostatic complex with a pseudo-natural polyelectrolyte (chitosan), a cationic polymer extracted from crustaceous shells. 

EPTMAC is used, for example, in the manufacture of cationic starch as a cationising chemical, in the manufacture of ion-exchange resins and in many other applications (Bergquist-Karlsson 1985 Estlander et al. 1997)- Other epoxy compounds are used, for example, in drug syntheses (Rudzki and Rebandel 1990 Buisson et al. 1991) or they can be found among the oxidation products of abietic and related acids (Hausen et al. 1990). 

The water-soluble polysaccharides are widely used to control the rheology of aqueous fluids in food, pharmaceutical, personal care, latex paints, and cosmetic products. They also have some uses in hard-smface care (toilet bowl cleaners, bathroom cleaners, etc.) and fabric care applications such as fabric softeners. The patent application EP 596580 Al is an example of a fabric softening composition thickened by cationic starch [39]. Specific examples of other consumer products will be provided in Sec. E.G. and Modified Natural Organic Thickeners. 

Modified starch finds several applications in industry, such as cationic starches for paper treatment. Thus the dominant use for starch is in paper making applications [59]. Since starch is less crystalline than cellulose it is more susceptible to chemical modification and hence more vulnerable to degradation during modification. Research into starch modification is mostly focused on improving starch moisture resistance without losing the favorable factors such as easy degradation and relatively low price. 

Special cationic pol5miers, which react with starch [native or anionic] by fixation and/or precipitation, proved to be even more effective in dry-strength improvement than cationic starch. Pol5nnnylamine was found to be especially useful in such applications. It forms a very stable complex with starch and paper fibers, which results in very good retention [23]. 

Starch, cooked in the paper mill or supplied as - pregelatinized starch, is used also. Modified starches (- oxidized starch, - cationic starch or - starch ethers) are common in that application. Sodium - carboxymethyl cellulose is also effective, but as an anionic polymer, it requires a retention aid such as alum. 

For practical uses see - anionic starches, car-boxymethyl starch, - cationic starches, - cross-linked starches, - hydrophobic starches, - oxidized starches, - starch industrial applications. 

Quaternary ammonium compounds (quats) are prepared - by moderate heating of the amine and the alkyl halide in a suitable solvent - as the chlorides or the bromides. Subsequently conversion to the hydroxides may be carried out. Major applications of the quat chlorides are as fabric softeners and as starch cationizing agent. Several bio-active compounds (agrochemicals, pharmaceuticals) possess the quat-structure. Important applications of quat bromides are in phase transfer catalysis and in zeolite synthesis. 

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