Poly Shellac

The poly(vinyl acetal) prepared from acetaldehyde was developed in the early 1940s by Shawinigan Chemicals, Ltd., of Canada and sold under the trade name Alvar. Early uses included injection-molded articles, coatings for paper and textiles, and replacement for shellac. Production peaked in the early 1950s and then decreased as a result of competition from less expensive resins such as poly(vinyl chloride) (see Vinyl polymers, poly(vinyl chloride)). 

Oxidized castor oils are excellent nonmigrating, nonvolatile plasticizers (qv) for ceUulosic resins, poly(vinyl butyral), polyamides, shellac, and natural and synthetic mbber (see Rubber, natural). The high viscosity products are also used as tackifiers in gasket compounds and adhesives (qv) because of good oil and solvent resistance. They also serve as excellent pigment grinding media and as a base for inks (qv), lubricating oils, and hydrauHc oils (62). 

In the past, the initial layers of coating (the sealing coat) were achieved by applying one or two coats of shellac. However, due to the variability between batches of this material, PVP-stabilized types of shellac or other polymeric materials, such as cellulose acetate phthalate (CAP) and poly(vinyl acetate phthalate) (PVAP), are now more popular. It should be appreciated that a fine balance must exist between minimizing the thickness of the sealing coat and providing an adequate moisture barrier. 

Both the poly (vinyl acetate)-poly (vinyl alcohol) and styrene-shellac examples of colloid participation in the polymerization require much investigation especially with respect to whether grafting to the colloid occurs in aqueous solutions or at the particle surface. The former would appear more likely for the relatively water soluble vinyl acetate monomer, while the latter should be favored for the less soluble styrene. In any case, both would result in identical particle stabilization. 

Cellulose acetate phthalate hypromellose phthalate poly-methacrylates shellac. 

Orkde. [Warner-Graham Ltd.] Shellac, lacquer solvents, water repellents, poly-uiediane, lacquer, alcohols. 

The term plastics first included only natural polymers—usually animal proteins (horn and tortoise shell), tree resins, or insect secretions called shellac—that were subsequendy mixed with fillers such as wood flour to yield substances having better molding properties. (A polymer, from the Greek word poly, meaning many, and mer meaning unit, is a molecule with an extremely high molecular weight.)... 

Remarkably, gelatin was not the only substrate explored for use with dichromates egg albumen, agar, casein, fish glue, shellac, and starch have all been tried and used. In modem times, synthetic polymers such as poly(vinyl alcohol), poly(vinyl pyrrolidone), and poly(vinyl butyral) have, to a significant extent, displaced the above natural materials for use with dichromates only gelatin and albumen have remained in use until quite recently. A typical modern recipe for dichromated albumen is given in Table 6.1. 

Aromatic hydrocarbons are used as diluents in solutions of cellulose nitrate, cellulose esters, and ethers with true solvents such as esters and ketones. Rubber, polyisobutene, and molten polyethylene also dissolve in them. Poly(vinyl chloride), solid polyethylene, polyamides, and shellac are, however, insoluble or only swell. 

Methyl acetate [79-20-9] is partially miscible with water and readily miscible with most organic solvents. It has a good solvency for cellulose esters and ethers, colophony, urea, melamine-, and phenol-formaldehyde resins, poly(vinyl acetate), alkyd resins, ketone resins, and other resins. It does not dissolve shellac, damar resin. 

Isobutyl acetate [110-19-0] is a colorless, neutral liquid with a pleasant, fruity odor. It is miscible with organic solvents, but immiscible with water. Isobutyl acetate has a high solvency for cellulose nitrate, colophony, damar resin, ketone and ketone-formaldehyde resins, maleate resins, urea and melamine resins, and phenolic and alkyd resins. Polymers such as polystyrene, poly(vinyl ethers), poly(vinyl acetate), polyacrylates, chlorinated rubber and vinyl chloride copolymers, as well as fats, greases, and oils are readily dissolved. Postchlorinated poly(vinyl chloride) is less soluble. Polyisobutene, cellulose ethers, polymethacrylates, poly(vinyl butyrals), natural rubber, and manila copal are swollen. Shellac, cellulose acetate, cellulose acetobutyrate, poly(vinyl chloride), and poly(vinyl formal) are insoluble. 

Cyclohexyl acetate [622-45-7] is very slightly miscible with water, but completely miscible with common organic solvents. Its solvency properties are comparable to those of amyl acetate. Cyclohexyl acetate dissolves oils, fats, resins, waxes, cellulose nitrate, cellulose tripropionate and acetobutyrate, alkyd resins, unsaturated and saturated polyester resins, phenolic resins and aminoplasts, poIy(vinyI chloride), vinyl chloride copolymers, poly(vinyl acetate), poly(vinyl ethers), epoxy resins, and acrylic resins, basic dyes, blown oils, crude rubber, metallic soaps, shellac, and bitumen. 

Ethyl triglycol [112-50-5] [2-(2-ethoxyethoxy)ethoxy]ethanol, triethylene glycol monoethyl ether] is an almost colorless, neutral, mild-smelling liquid with a low hygroscopicity. It is soluble in water and most organic solvents, but is only partially miscible with aromatic and aliphatic hydrocarbons. Ethyl triglycol dissolves cellulose nitrate, shellac, colophony, ketone resins, maleate resins, chlorinated rubber, alkyd resins, and many other paint resins. It does not dissolve cellulose acetate, poly(vinyl chloride), vinyl chloride copolymers, fats, oils, and rubber. 

Nitropropane [ 79-46-9] is a colorless, nonhygroscopic liquid with a mild odor. It dissolves cellulose nitrate, cellulose ethers, alkyd resins, chlorinated rubber, poly(vinyl acetate), vinyl chloride copolymers. Poly(vinyl chloride), colophony, polyacrylonitrile, waxes, rubber, and shellac are insoluble. It is used as a cosolvent in paints to improve pigment wetting, flow properties, and electrostatic processing it also reduces the paint drying time. 2-Nitropropane is classified as carcinogenic. 

Hydrogenated poly-1-decene Isomalt Lanolin Laurie acid Methyl rosinate Microcrystalline wax Mineral oil Myristic acid Oleic acid Palmitic acid Paraffin Pentaerythrityl rosinate Petrolatum Petroleum wax Rice (Oryza sativa) wax Shellac Stearic acid Zein glazing agent, sweets Calcium silicate glazing, pottery... 

A review of polymer history is beyond the scope of this paper and several such reviews are available. Most early polymer applications were modifications of poly(peptides) or poly(saccharides), although some other classes of natural polymers found utility. For example, shellac is a natural poly(ester) derived from from the excretions of the insect Lac-cifer lacca. While these materials were not recognized as polymers until... 

Alcohols are used at low levels in water based paints as coupling solvents with glycol ethers and in certain solvent coatings as latent solvents. n-Butanol and denatured ethanol are the most commonly used, with the latter also serving as an active solvent for shellac, poly(vinyl acetate), and several phenolics. 

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