Cellulose acetate propionate plastic

Cellulose Acetate, Propionate, and Butyrate. Cellulose acetate is prepared by hydrolyzing the triester to remove some of the acetyl groups the plastic-grade resin contains 38 to 40%... 

The cellulose esters with the largest commercial consumption are cellulose acetate, including cellulose triacetate, cellulose acetate butyrate, and cellulose acetate propionate. Cellulose acetate is used in textile fibers, plastics, film, sheeting, and lacquers. The cellulose acetate used for photographic film base is almost exclusively triacetate some triacetate is also used for textile fibers because of its crystalline and heat-setting characteristics. The critical properties of cellulose acetate as related to appHcation are given in Table 10. 

Although Lhe first cellulose plastic (cellulose nitrate plastic-based on an inorganic ester of cellulose) was developed in 1865. the first organic cellulose ester plastic was not offered commercially until 1927. In that year, cellulose acetate plastic became available as sheets, rods, and tubes. Two years later, in 1929. it was offered in the form of granules for molding. It was the first thermoplastic sufficiently stable to be melted without excessive decomposition, and it was the first thermoplastic to be injection molded. Cellulose acetate butyrate plastic became a commercial product in 1938 and cellulose propionate plastic followed in 1945. The latter material was withdrawn after a short time because of manufacturing difficulties, but it reappeared and became firmly established in 1955. 

Cellulose Acetate, Propionate, and Butyrate. Cellulose acetate is prepared by hydrolyzing the triester to remove some of the acetyl groups the plastic-grade resin contains 38-40% acetyl. The propionate and butyrate esters are made by substituting propionic acid and its anhydride (or butyric acid and its anhydride) for some of the acetic acid and acetic anhydride. Plastic grades of cellulose-acetate-propionate resin contain 39-47% propionyl and 2-9% acetyl cellulose-acetate-butyrate resins contain 26-39% butyryl and 12-15% acetyl. 

Transparency. Some applications of plastics require transparency. Amorphous plastics should be able to transmit light. Some factors which prevent transparency include unsatura-tion/light absorption, crystallinity, fillers and reinforcing fibers, and use of rubber particles to increase impact strength. The plastics most often used for their transparency are poly(4-methylpentene-l) (TPX), poly(methyl methacrylate) (almost equal to glass), cellulose acetate, propionate, and butyrate, polycarbonate, and polysulfones (slightly yellow). As a research challenge, it is quite possible that fillers and rubber particles could... 

Plastics that are commonly processed by extrusion include acrylics (polymethacrylates, polyacrylates) and copolymers of acrylonitrile cellulosics (cellulose acetate, propionate, and acetate butyrate) polyethylene (low and high density) polypropylene polystyrene vinyl plastics polycarbonates and nylons. The material properties and extrusion properties have been reviewed by Whelan and Dunning.Additives that may be included to modify or enhance proper-ties include lubricants and antislip agents to assist processing during extrusion plasticizers to achieve softness and flexibility stabilizers and antioxidants to retard or prevent degradation and dyes and pigments. 

For a wider range of properties, cellulose mixed esters have proved to be superior to the single esters, combining satisfactory strength with increased solubility and resistance to moisture as compared to the acetate. Cellulose acetate propionates and acetate butyrates have become commercially prominent, particularly in the fields of photographic films, plastics and lacquers. 

Practically all cellulose acetate manufactured at the present time is the acetone-soluble product, ranging from 37% to 41% acetyl content. Cellulose mixed esters now produced in quantity include cellulose acetate propionate of 33% propionyl content, cellulose acetate butyrate of 16% butyryl content, both of which are used largely for protective coatings and films, and cellulose acetate butyrate of 36% butyryl content used for plastics. 

The cellulose acetate propionates are Intermediate in properties between the cellulose acetates and the cellulose acetate butyrates, resembling the cellulose acetate butyrates in solubility and compatibility. Like the acetates, the propionates have practically no odor and thus can be used in applications where low odor is a requirement. These properties make the propionates especially useful in inks, overprints, plastic, and paper coatings, and various reprographic processes. CAP-482-0.5 requires moderately strong solvents to effect solution (Table VI). 

Uses of Propionic Acid. Propionic acid is used primarily as a grain and feed preservative for animal feed. This use, as with formic acid, is more prevalent in Europe than in the United States. The acid can be easily converted to propionate salts which are used for bread preservatives in the food industry. This application has been growing with the increase in population for the last few years, however, the trend toward health foods without preservatives could inhibit further growth in the future. The other uses for propionic acid are as a precursor for a variety of herbicides and relatively small-volume plastics, such as, cellulose acetate propionate [21]. 

Dimethyl phthalate (DMP) also has high dissolving capacity for CN. It has good compatibility with cellulose esters and are used in celluloid made fi-om CN and plastic compounds or films made from other cellulosic polymers, cellulose acetate (CA), cellulose acetate-butyrate (CAB), cellulose acetate-propionate (CAP), and cellulose propionate (CP). It is light stable but highly volatile. Diethyl phthalate (DEP) possesses properties similar to DMP and is slightly less volatile. 

Chem. Descrip. Pigment disp. in diisononyl phthalate plasticizers Uses Colorant for thermoplastics (cellulose acetate-butyrate, cellulose acetate-propionate, polycarbonates, PVC) and thermosets (adhesives and coatings, film and sheeting, moldings and extrusion, plastisols and rubber) extender... 

Typical degrees of substitution for plastics applications [21] are DS(acetate) = 2.5 for cellulose acetate, DS(propionate) = 2.6 andDS(acetate) = 0.1 for cellulose acetate propionate (CAP), and DS(butyrate) = 1.8 and DS(acetate) = 1.1 for cellulose acetate butyrate (CAB). In the industrial process of catalysed esterification, chain scission is a competitive reaction that can, however, be fairly well controlled under appropriate conditions [22]. Degrees of polymerization of commercial products can be estimated from literature data [22-25] to be in the range of 200 to 300. 

Sand, I.D. (1990) The dependence of properties of cellulose acetate propionate on molecular weight and the level of plasticizer. Journal of Applied Polymer Science, 40,943-952. 

EFFECT OF PLASTICIZERS ON POLYMER AND OTHER ADDITIVES Figures 11.7 and 11.8 show that both yield strength and elastic modulus of cellulose acetate propionate decreases linearly when the concentration of plasticizer increases. 

Cellulose acetate-propionate is used in flexographic ink formulations. The acetate-butyrate mixed esters are used in sheeting, molded plastics, hot melt dip coatings, lacquer coating and film products. The mixed proprionate-butyrate ester has excellent compatibility with oil-modified alkyl resins and is used in wood furniture coatings. 

Cellulose acetate (CA), cellulose acetate propionate (CAP), and cellulose acetate butyrate (CAB) are thermoplastic materials produced through esterification of cellulose and are used for many packaging applications. Different raw materials such as cotton, recycled paper, wood cellulose, and sugarcane are used in the production of cellulose ester biopolymers in powder form. Such cellulose ester powders in the presence of different plasticizers and additives are extruded to produce various grades of commercial cellulose plastics. Recently, Misra et al. successfully used melt intercalation technique for the fabrication of cellulose nanocomposites and studied the effect of C30B on its performance characteristics [44]. From the study, the... 

Cellulose, whose repeat structure features three hydroxyl groups, reacts with organic acids, anhydrides, and acid chlorides to form esters. Plastics from these cellulose esters are extruded into film and sheet and are injection molded to form a wide variety of parts. Cellulose esters can also be compression molded and cast from solution to form a coating. The three most industrially important cellulose ester plastics are cellulose acetate (CA), cellulose acetate butyrate (CAB), and cellulose acetate propionate (CAP), with structures as shown in Fig. 2.2. 

Cellidor Cellulose acetate propionate cellulose acetate butyrate Albis Plastics Germany www.albis.com... 

Cellulose acetate propionate AlbisCAPCP800(10% plasticizer) Cellulose acetate butyrate AlbisCABB900(10% plasticizer)... 

Materials such as metal, plastic, wood, paper, and leather are coated with pofymers primarily for protection and for the improvement of their properties. For this purpose, cellulose acetate (CA), cellulose acetate propionate (CAP), and cellulose acetate butyrate (CAB) are the most important classical and solvent-based cellulose esters of the coating industry [44]. Cellulose esters are widely used in composites and laminates as binder, filler, and laminate %ers. In combination with natural fibres, they can be used to some extent as composites from sustainable raw materials with good biodegradability. An additional domain of cellulose esters is their use in controlled-release systems, as well as membranes and other separation media [44, 47]. In the field of controlled-release systems, eellulose esters are used as enteric coatings, hydro-phobic matrices, and semipermeable membranes for appheations in pharmacy, agriculture, and cosmetics. 

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