Poly-acrylic ester compounds

Poly-acrylic ester compounds O ring compounds (Table 10.14)... 

Siding. The resin most used for siding is poly(vinyl chloride) homopolymer, compounded with modifiers, stabilizers, and pigments. Modifiers are most often acrylic esters, followed by chlorinated polyethylene or ethylene—vinyl acetate, used at 6—8 phr (parts per hundred resin). The modifier increases the impact strength of the rigid PVC. 

A large number of optically active poly-acryl-derivatives, mainly esters or amides, have been described in literature, although no series of homologous compounds has been systematically investigated. 

A comparison between the optical activity of some poly-acrylic or poly-methacrylic esters and of some model compounds, having approximately the same optical purity, shows that in general the optical activity is in both cases of the same order of magnitude (Table 19). 

Poly(vinyl alcohol) is utilized as a component of starch-based adhesives.11121114 Other patents report the use of partially oxidized starch,1115 dextrins,1116 dextrins and urea,1117 borax,1118 boric acid,1119 and vinyl methyl ether-maleic acid copolymers.1120 Other patents indicate the use of poly (vinyl alcohol) with partially hydrolyzed poly(vinyl acetate),1121 nonhy-drolyzed poly(vinyl acetate),1122 and poly(vinyl chloride).1123 A few patents have reported such poly acrylic additives as poly (acrylic acid)1124 and its salts,1125 poly(acrylamide),1126 1127 A-methylacrylamide or poly(A-acryl-amide),1128 and polyethyleneimine.1129 Polystyrene has also been used,1130 as well as more complex copolymers such as a maleic acid monobutyl ester-methyl vinyl ether copolymer, together with dextrin and polyacrylamide),1131 carboxylated ethyl acrylate-styrene zinc salt copolymer,1132 ethylene-methyl acrylate-vinyl acetate copolymer,1133 vinyl acetate-vinyl pyr-rolidone copolymer,1134 and ethylene-vinyl acetate copolymer.1135 Some adhesives are compounded with SBR latex1136 1138 and phenol-formaldehyde resins.1139... 

Acrylates Acrylonitriles Allyl Esters Cellulose esters Epoxies Ethylenic (unsaturated) hydrocarbons Poly-hydroxy esters(eg Pentaerythritol tetramethacrylate,Ethylene Glycol diacrylate) Polyolefins Vinyl compound esters, acids)... 

Some other compounds are identifiable as methyl esters although they were not seen in the pyrogram of poly(acryiic acid) because they are not eluted as free acids from the Carbowax column. One additional observation is that the pyrogram after methylation shown in Figure 6.7.4 and that of poly(methyl acrylate) given in Figure 6.7.7 show high similarity. This indicates that pyrolysis mechanisms of poly(acrylic acid) and of poly(methyl acrylate) are very similar. 

As seen from several examples, the main characteristic of pyrolysis of poly(acrylic acid esters) is the formation of monomer, dimer, trimer, etc. The specific yield of monomer, dimer, trimer, etc. is temperature dependent, higher temperatures favoring the formation of lower molecular weight compounds. 

The class of compounds called polyesters consists of aU heterochain macromolecular compounds that possess repeat carboxylate ester groups in the backbones. This excludes all polymers with ester groups located as pendant groups, like acrylic and methacrylic polymers, poly(vinyl esters), and esters of cellulose, or starch. What remains, however, is still a large group of polymeric materials that can be subdivided into saturated and unsaturated polyesters. 

Two types of stabilizers are used, one of which is basically the type of water-soluble polymers (often in the presence of an electrolyte or a buffer) and the other is a type of water-insoluble inorganic compounds. The former type includes polyvinyl alcohol (PVA), hydroxypropyl cellulose, sodium poly(styrene sulfonate), and sodium salt of acrylic acid-acrylate ester copolymer. The latter type includes magnesium silicate hydroxide (TALC), hydroxyapatite, barium sulfate, kaolin, magnesium carbonate and hydroxide. 

Concentrated aqueous solutions of poly(acrylic acids) are thixotropic [447], of poly(methacrylic acid) are rheopectic [448]. Acrylic acid and methacrylic acid easily copolymerize together or with acrylic and methacrylic esters, acrylonitrile, vinylpyrroli-done, styrene, and others. The copolymers are of technical importance. Copolymers with four to six different compounds are quite common. 

The earliest study describing vulcanised polymers of esters of acryUc acid was carried out in Germany by Rohm (2) before World War I. The first commercial acryUc elastomers were produced in the United States in the 1940s (3—5). They were homopolymers and copolymers of ethyl acrylate and other alkyl acrylates, with a preference for poly(ethyl acrylate) [9003-32-17, due to its superior balance of properties. The main drawback of these products was the vulcanisation. The fully saturated chemical stmcture of the polymeric backbone in fact is inactive toward the classical accelerators and curing systems. As a consequence they requited the use of aggressive and not versatile compounds such as strong bases, eg, sodium metasiUcate pentahydrate. To overcome this limitation, monomers containing a reactive moiety were incorporated in the polymer backbone by copolymerisation with the usual alkyl acrylates. 

Strictly speaking, the term polyester ought to refer to a chemical compound containing many ester groups in each molecule. In practice, however, it usually refers to polymeric materials containing ester groups as major structural components of the main chains of the macromolecules of which the polymer is composed, and this is the sense in which it is used here. The term is not now usually applied to polymers that contain ester groups attached to the main chain either directly, as in cellulose triacetate, poly(vinyl acetate) or poly(methyl acrylate), or within short side-chains. 

Poly (methyl methacrylate). Acrylic acid is H2C=CH—COOH and methacrylic acid is H2C=C(CH3)COOH. These compounds and their methyl esters are both quite reactive and difficult to store and handle. The monomer used to form poly (methyl methacrylate), 2-hydroxy-2-methylpropanenitrile, is prepared by the following reaction ... 

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