Polymer ester copolymers

Under conditions of extreme acidity or alkalinity, acryhc ester polymers can be made to hydroly2e to poly(acryhc acid) or an acid salt and the corresponding alcohol. However, acryhc polymers and copolymers have a greater resistance to both acidic and alkaline hydrolysis than competitive poly(vinyl acetate) and vinyl acetate copolymers. Even poly(methyl acrylate), the most readily hydroly2ed polymer of the series, is more resistant to alkah than poly(vinyl acetate) (57). Butyl acrylate copolymers are more hydrolytically stable than ethyl acrylate copolymers (58). 

The vast majority of all commercially prepared acryUc polymers are copolymers of an acryUc ester monomer with one or more different monomers. Copolymerization gready increases the range of available polymer properties and has led to the development of many different resins suitable for a broad variety of appHcations. Several review articles are available (84,85). 

In 1989 the U.S. production of acryflc ester monomers was ca 450,000 t. This represents about 45% of the worldwide production Western Europe (ca 35%) and Japan (ca 15%) account for most of the remainder. Essentially all of this was converted to acryflc polymers and copolymers. The U.S. production is principally from four companies ... 

The most common VI improvers are methacrylate polymers and copolymers, acrylate polymers (see Acrylic ester polymers), olefin polymers and copolymers, and styrene—butadiene copolymers. The degree of VI improvement from these materials is a function of the molecular weight distribution of the polymer. VI improvers are used in engine oils, automatic transmission fluids, multipurpose tractor fluids, hydrautic fluids, and gear lubricants. Their use permits the formulation of products that provide satisfactory lubrication over a much wider temperature range than is possible using mineral oils alone. 

A process based on saponification of ethylene—acrylate ester copolymers has been practiced commercially in Japan (29). The saponification naturally produces fully neutralized polymer, and it is then necessary to acidify in order to obtain a pardy neutralized, melt-processible product. Technology is described to convert the sodium ionomer produced by this process to the zinc type by soaking pellets in zinc acetate solution, followed by drying (29). 

A substantial fraction of commercially prepared methacrylic polymers are copolymers. Monomeric acryUc or methacrylic esters are often copolymerized with one another and possibly several other monomers. Copolymerization greatiy increases the range of available polymer properties. The aH-acryhc polymers tend to be soft and tacky the aH-methacryhc polymers tend to be hard and brittie. By judicious adjustment of the amount of each type of monomer, polymers can be prepared at essentially any desired hardness or flexibiUty. Small amounts of specially functionalized monomers are often copolymerized with methacrylic monomers to modify or improve the properties of the polymer directiy or by providing sites for further reactions. Table 9 lists some of the more common functional monomers used for the preparation of methacrylic copolymers. 

Standard-grade PSAs are usually made from styrene-butadiene rubber (SBR), natural rubber, or blends thereof in solution. In addition to rubbers, polyacrylates, polymethylacrylates, polyfvinyl ethers), polychloroprene, and polyisobutenes are often components of the system ([198], pp. 25-39). These are often modified with phenolic resins, or resins based on rosin esters, coumarones, or hydrocarbons. Phenolic resins improve temperature resistance, solvent resistance, and cohesive strength of PSA ([196], pp. 276-278). Antioxidants and tackifiers are also essential components. Sometimes the tackifier will be a lower molecular weight component of the high polymer system. The phenolic resins may be standard resoles, alkyl phenolics, or terpene-phenolic systems ([198], pp. 25-39 and 80-81). Pressure-sensitive dispersions are normally comprised of special acrylic ester copolymers with resin modifiers. The high polymer base used determines adhesive and cohesive properties of the PSA. 

One-to-one random copolymers of acrylic acid with either hydroxyethyl acrylate (a hydrogel model) or methyl acrylate failed to protect insulin from release under gastric conditions (Figure 6). In the case of the hydrogel, the expected swelling due to exposure to water occurred, releasing insulin. The behavior of the ester copolymer led to the prediction that there should be no more than about four carbon atoms per carboxylic acid group in a repeat unit of the polymers. We have not been able to disprove this hypothesis thus far. 

The acrylic family of polymers includes polymers and copolymers of acrylic and methacrylic acids and esters, acrylonitrile, and acrylamide [Kine and Novak, 1985 Nemec and Bauer, 1985 Peng, 1985 Thomas and Wang, 1985],... 

The resins used are polymers and copolymers of the esters of acrylic and methacrylic acids. They range in physical properties from soft elastomers to hard plastics, and are used in cementitious compounds in much the same manner as SBR latex. Acrylics are reported to have better UV stability than SBR latex and therefore remain flexible under exterior exposure conditions longer than SBR latex [88]. 

Actually, these considerations are confirmed by experiments 82). The systems investigated are shown in Table 8, No. 4, which are induced cholesteric polymer systems. The nematogenic host molecules of benzoic acid phenyl esters are linked via spacers of different length m (m = 3, 4, 5, 6) to the polymer backbone. The polymers are converted to polymers having a cholesteric phase by the chiral cholesteryl derivative, which is also linked to the polymer backbone (copolymer). 

Raw-gum fluorocarbon elastomers are transparent to translucent with molecular weights from approximately 5000 (e.g., VITON LM with waxy consistency) to over 200,000. The most common range of molecular weights for commercial products is 100,000 to 200,000. Polymers with molecular weights over 200,000 (e.g., Kel-F products) are very tough and difficult to process. Elastomers prepared with vinylidene fluoride as comonomer are soluble in certain ketones and esters, copolymers of IFF and propylene in halogenated solvents perfluorinated elastomers are practically insoluble.16... 

For food contact articles made from acrylic and methacrylic acid ester copolymers and their polymer blends, the following starting materials can be used ... 

Polymer Preparation. The polyether-ester copolymers were prepared by titanate-ester-catalyzed, melt transesterification of a mixture of PTME glycol, the dimethyl ester of an aromatic diacid, and a diol present in 50-100% molar excess above the stoichiometric amount required (Figure 1). The reactions were carried out in the presence of no more than 1 wt %, based on final polymer, of an aromatic-amine or hindered-... 

Up to this point the discussion has been concerned with alkylene terephthalate/PTME terephthalate copolymers in which the concentration of alkylene terephthalate and the chemical structure of the alkylene groups have been varied. The next section of this report is concerned with polyether-ester copolymers in which aromatic esters other than terephthalate are used in combination with PTME glycol and various diols. The objective is the same, to correlate changes in copolymer structure with changes in copolymerization results and copolymer properties. Once again the 50% tetramethylene terephthalate/PTME terephthalate copolymer (Tables I and II) with its excellent properties and relative ease of synthesis will be used as the point of reference to which the other polymers will be compared. 

Among the terephthalate-based polyether-ester copolymers, those prepared using 1,4-butanediol as the diol monomer exhibit the best overall physical properties. The use of ethylene glycol as the diol monomer retards the rate of polymer formation and results in copolymers which crystallize slowly. Other aliphatic ,w-diols yield terephthalate-based polyether-ester copolymers which are low in tensile strength and tear strength relative to the 1,4-butanediol-based copolymer. Terephthalate-based copolymers prepared with 1,4-benzenedimethanol as the diol monomer are relatively low in inherent viscosity, tensile strength, and tear strength. 

About 1.1 billion lb of phthalic anhydride are produced annually in the United States. The major uses are in plasticizers, alkyd resins, and unsaturated polyester resins. The plasticizers are esters made by reacting two moles of an alcohol, such as 2-ethylhexanol, with one mole of phthalic anhydride. These plasticizers find major use in vinyl chloride polymers and copolymers. Alkyd resins are a type of polyester resin used in surface coatings. The most rapidly growing end use is in unsaturated polyester resins for reinforced plastics. 

Vinyl lacquers are used mainly where a high degree of chemical resistance is required these lacquers are based on vinyl chlorides and vinyl acetates. Acrylic lacquers are based on methyl methacrylate and methyl acrylate polymers and copolymers. Other esters of acrylic and methacrylic acid also may be used to make nonconvertible film formers. Judicious selection of these acrylic acid or methacrylic acid esters allows one to produce film formers with specifically designed properties such as hardness, flexibility, gloss, durability, heat, and chemical resistance. Acrylic lacquers, however, are not noted for their water resistance. The principal uses of acrylic-type lacquers are fluorescent and metallic paints, car refinish applications, clear lacquers and sealers for metals, and protective coatings for aircraft components and for vacuum-deposited metals, as well as uses in pigmented coatings for cabinets and appliances. 

Acrylate and styrene polymers as well as polysiloxanes with 11-phenoxy-naphthacene-5,12-quinone side groups (IIIB) were synthesized using the reaction of the active ester copolymers with 6-[(tyrosinebutylester)o-yl]-5,12-naphthacenequi-none.53... 

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