Hydroxyl Alkyl Acrylate

A cost-effective and environmentally friendly defoamer formulation which does not contain oil, ethylene bis-stearamide or free silicone for use in various industrial applications (29). The defoamer formulation is a mixture of a polymer containing acrylic acid, methacrylic 

A pol nner containing 10-30% hydroxyl alkyl acrylate and 70-90% alkyl acrylate by weight percent was prepared as follows (29)  

---

The minimum requirements for a dispersion polymerization are monomer, solvent/nonsolvent, initiator, and steric stabilizer. The monomer must be soluble in the reaction mixture and its polymer, insoluble. The monomers used in systems of commercial interest are methyl methacrylate, vinyl chloride, vinyli-dene chloride, vinyl esters, hydroxyl alkyl acrylates. A typical recipe for dispersion polymerization is shown in Table 9. 

Esters. Most acryhc acid is used in the form of its methyl, ethyl, and butyl esters. Specialty monomeric esters with a hydroxyl, amino, or other functional group are used to provide adhesion, latent cross-linking capabihty, or different solubihty characteristics. The principal routes to esters are direct esterification with alcohols in the presence of a strong acid catalyst such as sulfuric acid, a soluble sulfonic acid, or sulfonic acid resins addition to alkylene oxides to give hydroxyalkyl acryhc esters and addition to the double bond of olefins in the presence of strong acid catalyst (19,20) to give ethyl or secondary alkyl acrylates. 

A very convenient method to obtain a macromer (structure 6.13) is by using an unsaturated isocyanate [50] or by using some accessible raw materials, by the reaction of a hydroxy alkyl acrylate or methacrylate with one -NCO group of a diisocyanate for example, 2,4 toluene diisocyanate (TDI) and to react the remaining -NCO group with the terminal hydroxyl group of a polyether polyol ... 

This approach has been applied [295,298-301] to the reactivity of a large series of carbon-centered radicals (including the benzoyl, hydroxyl alkyl, and aminoalkyl radicals) toward various monomer units (acrylate, methacrylate, vinylether, vinylacetate, etc.). Calculating a and A/i X) yields Zsenth. Linear relationships between Zsenth and A//, are generally found (Equation 10.78). 

In numerous synthetic studies it has been demonstrated that DMP can be used for a selective oxidation of alcohols containing sensitive functional groups, such as unsaturated alcohols [297,1215-1218], carbohydrates and polyhydroxy derivatives [1216, 1219-1221], silyl ethers [1222,1223], amines and amides [1224-1227], various nucleoside derivatives [1228-1231], selenides [1232], tellurides [1233], phosphine oxides [1234], homoallylic and homopropargylic alcohols [1235], fluoroalcohols [1236-1239] and boronate esters [1240]. Several representative examples of these oxidations are shown below in Schemes 3.349-3.354. Specifically, the functionalized allylic alcohols 870, the Baylis-Hillman adducts of aryl aldehydes and alkyl acrylates, are efficiently oxidized with DMP to the corresponding a-methylene-p-keto esters 871 (Scheme 3.349) [1217]. The attempted Swern oxidation of the same adducts 870 resulted in substitution of the allylic hydroxyl group by chloride. 

Monomers, according to their contributions in the final products, can be classified as hard monomers, soft monomers, and functional monomers. The monomers such as MMA, styrene (St), acrylonitrile (AN), and vinyl acetate (VAc) can increase the hardness of the polymers, so called as hard monomers. Most of acrylic and alkyl acrylate monomers, because their polymers are softer than the polymers of the above mentioned monomers, are called as soft monomers. Functional monomers can be hydroxyl group containing monomers and amine containing monomers, such as the monomers listed in Table 11.4. 

Reaction conditions depend on the reactants and usually involve acid or base catalysis. Examples of X include sulfate, acid sulfate, alkane- or arenesulfonate, chloride, bromide, hydroxyl, alkoxide, perchlorate, etc. RX can also be an alkyl orthoformate or alkyl carboxylate. The reaction of cycHc alkylating agents, eg, epoxides and a2iridines, with sodium or potassium salts of alkyl hydroperoxides also promotes formation of dialkyl peroxides (44,66). Olefinic alkylating agents include acycHc and cycHc olefinic hydrocarbons, vinyl and isopropenyl ethers, enamines, A[-vinylamides, vinyl sulfonates, divinyl sulfone, and a, P-unsaturated compounds, eg, methyl acrylate, mesityl oxide, acrylamide, and acrylonitrile (44,66). 

Thus the reactions of cyclic or acyclic enamines with acrylic esters or acrylonitrile can be directed to the exclusive formation of monoalkylated ketones (3,294-301). The corresponding enolate anion alkylations lead preferentially to di- or higher-alkylation products. However, by proper choice of reaction conditions, enamines can also be used for the preferential formation of higher alkylation products, if these are desired. Such reactions are valuable in the a substitution of aldehydes, which undergo self-condensation in base-catalyzed reactions (117,118). Monoalkylation products are favored in nonhydroxylic solvents such as benzene or dioxane, whereas dialkylation products can be obtained in hydroxylic solvents such as methanol. The difference in products can be ascribed to the differing fates of an initially formed zwitterionic intermediate. Collapse to a cyclobutane takes place in a nonprotonic solvent, whereas protonation on the newly introduced substitutent and deprotonation of the imonium salt, in alcohol, leads to a new enamine available for further substitution. 

Carbon Chain Backbone Polymers. These polymers may be represented by (4) and considered derivatives of polyethylene, where n is the degree of polymerization and R is (an alkyl group or) a functional group hydrogen (polyethylene), methyl (polypropylene), carboxyl (poly(acrylic acid)), chlorine (poly(vinyl chloride)), phenyl (polystyrene) hydroxyl (poly(vinyl alcohol)), ester (poly(vinyl acetate)), nitrile (polyacrylonitrile), vinyl (polybutadiene), etc. The functional groups and the molecular weight of the polymers, control their properties which vary in hydrophobicity, solubility characteristics, glass-transition temperature, and crystallinity. 

The structure of the liquid- liquid interfadal layer depends on the difference in polarity between the two liquids (Kaeble, 1971). Asymmetric molecules of some liquids display a molecular orientation on the interface which is indicative of their structure. Thus, interfacial tension at the octane-water interlace is SO.S nm/m whereas at the octanol-water interne it is only 8.8 nm/m. Reduction of inter dal tension in the latter case points to the orientation of octanol hydroxyl groups toward water, in other words to the structure and polarity of the interfadal layer. Because of such an orientation, the stimulus for adsorption of other asymmetric molecules on the interface is decreased. A similar pattern is typical of the homologous series of lower attcy] acrylates at the interface with water the carbonyl groups of their asymmetrical molecules are oriented toward water this orientation is more eSective the higher the polarization of the carbonyl, i.e the smaller the alkyl. Interfadal tension decreases in the same order from 27.2 nm/m for hexyl acrylate (Yeliseyeva et at, 1978) to 8 nm/m for methyl acrylate (datum from our laboratory by A, Vasilenko). 

Due to the attractivity of this method several groups have developed onium salt supported versions of classical reactions. For example, starting from hydroxyl derived imidazolium salts, formation of supported acrylates with acryloyl chloride followed by reaction with diene in refluxing toluene afforded Diels Alder adduct in good yields (>65%). After saponification, products are isolated without further purification [127], Alternatively, starting from carboxylic acid derived imidazolium salts, acyl chloride formation with thionyl chloride in acetonitrile, followed by reaction with 4-aminophenol led to supported N-arylamide. Williamson alkylation using NaOH as a base and subsequent cleavage from the onium salt support under acidic condition (HCI/I I2()/ AcOH) allowed for isolation of various alkoxy substituted anilines with >98% purity... 

Poly(2-alkyl oxazoline)s having methacrylate or acrylate end groups were prepared by two methods [182]. a) Living polyoxazoline chains, prepared using methyl p-toluene sulphonate as initiator, were end-capped by reaction with metal salts or tetraalkylammonium salts of acrylic or methacrylic acid or a trialky-lammonium salt or trimethylsilyl ester of methacrylic acid (functional termination). b) The living polymers were terminated with water in the presence of Na2C03 to provide hydroxyl-terminated chains. Subsequent acylation with acry-loyl or methacryloyl chloride in the presence of triethylamine led to the formation of the macromonomers. The procedures are outlined in the following Scheme 51. 

Alkylated melamine-, urea-, and benzoguanamine-formaldehyde resins are the principal cross-linking agents in many industrially applied baked coatings. They are combined with acrylic, alkyd, epoxy, and polyester resins. The amide, hydroxyl, or carboxyl groups of these backbone polymers are used as functional sites for reaction with the amino resin. 

Emulsion polymers derived from acrylic monomers are easily the most composi-tionally diverse and versatile family of the commercially important broad classes of emulsion polymers. By acrylic we mean polymers of mcHiomeric alkyl esters of acrylic and methacrylic acid, but also include, usually as lesser components of the polymers, the free acids themselves and derivatives such as their amides, nitriles and aldehydes, as well as amides and esters bearing functional groups on the side chain, such as hydroxyl. 

The vinyl urethanes are normally derived from hydroxyl-terminated unsaturated polyester alkyds, e.g., propoxylated bisphenol A fumarate, which have been end-capped with a polyisocyanate and then subsequently end-capped with an hydroxy alkyl methacrylate. Thus, these resins have both terminal acrylic and in-chain maleate/fumarate unsaturation, the ratio depending on the oligomer molecular weight and the functionality of the polyisocyanate. High molecnlar weight results in a lower terminal in-chain unsaturation ratio, while a polyisocyanate fimctionality > 2 increases the ratio. A typical oligomer structure is shown in Structure 9.3 [13,14]. 

The side chain LC polymer via conventional route is made by polymerizing two acrylate/methacrylate monomers in which one has free hydroxyl side group (5-8%) linked via long alkyl chain and the other has LC moiety linked via alkyl chain spacer. This hydroxyl is later crosslinked by using diisocyanates such as, hexamethylene diisocyanate etc. to get LC elastomer (Figure 8.20) [53]. 

---