Starch acetate films

Tuovinen, L., Peltonen, S., Jarvinen, K. (2003). Drug release from starch-acetate films. Journal of Controlled Release, 91(3), 345-354. 

Tarvainen et al. (2002) studied the film-forming ability of starch acetate (DS 2.8) and the effect of commotfly used plasticizers on the physical properties of starch acetate films. The properties were compared with ethylcellulose films. Mechanical studies, water vapor and drug permeability tests, and thermal analysis by differential scarming calorimetry (DSC) were used to characterize the film-forming ability of starch acetate and efficiency of tested plasticizers. Starch acetate films were foimd to be tougher and stronger than ethylcellulose films at the same plasticizer concentration. Also, in most cases, the water vapor permeability of starch acetate... 

Starch acetates may have low or high DS. The industrial importance of low DS acetates results from their abiUty to stabilize aqueous polymer sols. Low DS acetates inhibit association of amylose polymers and reduce the association of the longer outer chains of amylopectin. These properties are important in food appHcations. Highly derivatized starches (DS 2—3) are useful because of their solubiHty in organic solvents and abiHty to form films and fibers. 

Low DS starch acetates have reduced gelatinization temperature ranges and reduced tendency to retrograde after pasting and cooling. Gelling may be completely inhibited if the DS is sufficiently high. Low DS starch acetate polymers also form films which are useful in textile and paper manufacture. 

Using acetic acid, starch acetates are formed, which are used as film-forming polymers for pharmaceutical products, and as the polymer in biodegradable packing-foam peanuts. Starch acetates have a lower tendency to create gels than unmodified starch. 

Tarvainen, M., Sutinen, R., Peltonen, S., Tiihonen, P, Paronen, P. (2002). Starch acetate-a novel film-forming polymer for pharmaceutical coatings. J. Pharm. ScL, 91(1), 282-289. 

Tuovinen,L.,Peltonen, S.,Liikola,M.,Hotakainen,M.,Lahtela-Kakkonen, M.,Poso, A., Jarvinen,K. (2004). Drug release from starch-acetate microparticles and films with and without ineorporated a-amylase. Biomaterials, 25(18), 4355M362. 

Film, cellulose acetate, I, 300 cellulose ester, I, 325 starch acetate, I, 297 Fischer cyanohydrin synthesis of higher-C sugars, I, 1-38... 

The preparation of the first starch acetate, as well as the first cellulose acetate, was announced by SchUtzenberger in 1865. These acetates were prepared by heating the carbohydrates in acetic anhydride to about 140-160 . Further examination of this reaction has been made by Traquair who found that on heating starch to 90° with acetic anhydride a derivative of low acetyl content (1-4%) is obtained which is capable of forming clear, somewhat elastic films. This starch acetate, termed Feculose, was produced commercially for a time, being sold for use as a thickening agent and as a size for textiles and paper. 

Paralleling their film-forming properties, these amylose triacetates can be molded into strong, tough plastics, but the amylopectin triacetates yield only very brittle products. Similarly, Mullen and Pacsu have shown that whole starch acetate produces clear, transparent, molded pieces which, however, are brittle. 

As amylopectin predominates in all known starches, the poor film-forming properties of whole starch acetates become understandable. Artificial mixtures of amylose and amylopectin triacetates (acetylated fractions A and B) show increasingly poor film-forming properties as the proportion of amylopectin acetate in the mixture is increased. 

Starch acetates normally contain 2 to 3% moisture. They have a strong binding power for water as is indicated by the observation that an unplasticized amylose (fraction A) triacetate film soaked in water will lose about one-third of its tensile strength. 

Acylated starch can be copolymerized to yield materials for films, lacquers, and fibers.2111 Starch acetate copolymerized with epichlorohydrin was extruded to give cold-water swelling products with a high degree of friability.2112 Epichlorohydrin-crosslinked starch has been acylated with 2,3-di-O-benzoyl-L-threaric anhydride.2113 The reaction proceeded either in /V,/V-dimethy 11 ormam ide or in toluene, and the non-crosslinked product has also been reported.2114... 

Purification and Physical and Chemical Properties. Extracellular cellulase components A and B and cell-bound cellulase component C were purified through the steps summarized in Figure 7 from the cultures of Ps. fluorescens on 0.5% Avicel and on 0.5% cellobiose, respectively. The purified cellulase components (Cellulases A, B, and C) thus obtained showed a single peak in zone electrophoresis on cellulose acetate film and starch bed. 

Hazardous Decomp. Prods. CO, CO2, acrid fumes NFPA Health 2, Flammability 3, Reactivity 2 Uses Monomer for synthesis of nitrile rubber, PVAc emulsions, PVOH, EVA copolymers, vinyl chloride-vinyl acetate copolymers, PVBI, and vinyl acetate-acrylonitrile copolymers in polymerized form for plastic masses, films, lacquers, latex paints, adhesives, textile finishing, safety glass interlayers textile hand modifier binder for paper coatings esterification for food starch modified film-former in cosmetics food pkg. adhesives resinous/polymeric food-contact coatings for polyolefin films food-contact paper/paperboard, ionomeric resins, copolymers, laminates, resin-bonded filters, textiles... 

Starch, acetate, ether with 1,2,3-propanetriol (2 1). See Acetylated distarch glycerol Starch acetate, oxidized Starch, acetylated, oxidized. See Acetylated oxidized starch Starch/acrylates/acrylamide copolymer Definition Polymer of starch, acrylamide and a monomer consisting of acrylic acid, methacrylic acid, or one of their simple esters Uses Binder, film-former in cosmetics superabsorbent polymer for wound dressings, topical applies. 

High DS starch acetates are used to create brittle films and molded products. These have had little application, due to the economic superiority of cellulose acetates. In general, specific gravity and melting temperature both decrease with an increase in acetylation (45). Highly acetylated starches above 15% acetyl content (DS approximately 0.7) are soluble in water at 50° to 100°C and insoluble in organic solvents. When the acetyl content reaches 40% (DS approximately 2.5), the derivatized starch is soluble in aromatic hydrocarbons, ketones, and glycol ethers. 

Chitosan solntion was prepared in acetic acid solution (chitosan acetic acid = 5 4). Starch powder was mixed with glycerol homogenously with the above prepared chitosan solution to form 15% starch and chitosan s isoUd gel-like mixtures by heating at lOO C for 2h. The gel-like mixtures in hot state were cold pressed to prepare wet starch/chitosan films. 

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