Hydrocarbon resins effect

Friedel-Crafts (Lewis) acids have been shown to be much more effective in the initiation of cationic polymerization when in the presence of a cocatalyst such as water, alkyl haUdes, and protic acids. Virtually all feedstocks used in the synthesis of hydrocarbon resins contain at least traces of water, which serves as a cocatalyst. The accepted mechanism for the activation of boron trifluoride in the presence of water is shown in equation 1 (10). Other Lewis acids are activated by similar mechanisms. In a more general sense, water may be replaced by any appropriate electron-donating species (eg, ether, alcohol, alkyl haUde) to generate a cationic intermediate and a Lewis acid complex counterion. 

G-5—G-9 Aromatic Modified Aliphatic Petroleum Resins. Compatibihty with base polymers is an essential aspect of hydrocarbon resins in whatever appHcation they are used. As an example, piperylene—2-methyl-2-butene based resins are substantially inadequate in enhancing the tack of 1,3-butadiene—styrene based random and block copolymers in pressure sensitive adhesive appHcations. The copolymerization of a-methylstyrene with piperylenes effectively enhances the tack properties of styrene—butadiene copolymers and styrene—isoprene copolymers in adhesive appHcations (40,41). Introduction of aromaticity into hydrocarbon resins serves to increase the solubiHty parameter of resins, resulting in improved compatibiHty with base polymers. However, the nature of the aromatic monomer also serves as a handle for molecular weight and softening point control. 

Dampproofing admixtures are formulated to affect the properties of the hardened concrete, and not those of concrete in its plastic state. In the case of materials based solely on calcium and aluminum stearates, stearic acid in solid or emulsion form, bitumens and hydrocarbon resins, there will be no effect on the properties of the plastic concrete with regard to air content, workability, mix design parameters, etc. When water-reducing admixtures or accelerators are included in the formulation, the effect on the concrete will be a function of the particular type of material used (see relevant section). The wax emulsions do appear to have an effect on the properties of the plastic concrete because of the lubrication effect of the very small... 

Solubility. At long oil lengths, the aliphatic hydrocarbon chains of the fatty acids constitute the major portion of the mass of the resin molecules therefore, the resin is soluble in nonpolar aliphatic solvents. Conversely, as the oil length decreases and the phthalic content increases, the aromaticity of the resin molecules increases, and the aromaticity and/or the polarity of the solvent must be increased in order to dissolve the resin effectively. 

Processing Agents The situation with these agents is analogous to the aromatic plasticizers Attention must be directed to the aromatic hydrocarbon resins and to the components resorcin and formaldehyde, with their enhancing effects on adhesion to structural elements, as weU as to isocyanates and some peptizers. 

The similarity in chemical structure to isoprene explains why these are quite compatible with natural rubber and synthetic isoprene-based polymers (or block copoljuners). The C-9 aromatic hydrocarbon resins include indene- and styrene-based oligomers. Because of the difference in chemical structure these will associate with the end-blocks in S-I-S copolymers, and thus have a reinforcing effect and improve high temperature performance. Finally, mixtures of aliphatic and aromatic hydrocarbon resins are commonly used as a way to tailor compatibility and physical properties of the resultant PSAs. 

Figure 4.27. Effect of plasticizer on the indentation of crosslinked nitrile rubber 5°C/min, no plasticizer (medium dashed line) lOphr coumarone indene resin (solid line) lOphr hydrocarbon resin (long dashed line) lOphr hydroxy resin (short dashed line) [from Brazier and Nickel (1978) reprinted with permission of Elsevier].

POLYOLEFIN AND ETHYLENE COPOLYMER-BASED HOT MELT ADHESIVES 413 Table 5. Effect of Aromaticity on Hydrocarbon Resin. ... 

Chemical Properties. A combination of excellent chemical and mechanical properties at elevated temperatures result in high performance service in the chemical processing industry. Teflon PEA resins have been exposed to a variety of organic and inorganic compounds commonly encountered in chemical service (26). They are not attacked by inorganic acids, bases, halogens, metal salt solutions, organic acids, and anhydrides. Aromatic and ahphatic hydrocarbons, alcohols, aldehydes, ketones, ethers, amines, esters, chlorinated compounds, and other polymer solvents have Httle effect. However, like other perfluorinated polymers,they react with alkah metals and elemental fluorine. 

In terms of general solvency, solvents may be described as active solvents, latent solvents, or diluents. This differentiation is particularly popular in coatings applications, but the designations are useful for almost any solvent appHcation. Active solvents are strong solvents for the particular solute in the apphcation, and are most commonly ketones or esters. Latent solvents function as active solvents in the presence of a strong active solvent. Alcohols exhibit this effect in nitrocellulose and acryUc resin solutions. Diluents, most often hydrocarbons, are nonsolvents for the solute in the apphcation. 

Terpene monomers are another class of interesting natural monomers because they give, on polymerization, hydrocarbon therplastic resins that exhibit a high degree of tackiness useful in pressure sensitive tapes [25]. They are also used for sizing paper and textile materials. Terpene-phenol resins are effective heat stabilizers for high-density polyethylene. 

TBA and isobutene have been compared as the etherifying agent at 60 °C. The initial molar ratio of isobutene to glycerol was 4.0 with Amberlyst A35 as the catalyst. The conversion of glycerol is lower when etherified with TBA than when etherified with isobutene. More hydrocarbons are formed with isobutene than with TBA. But, with TBA, mainly monoethers are formed and valuable triethers are formed only in small amounts. In addition, TBA dehydrates to water, which has an inhibition effect on ion-exchange resin catalysts [23],... 

U.S. EPA. A literature survey oriented towards adverse environmental effects resnltant from the nse of azo componnds, brominated hydrocarbons, EDTA, formaldehyde resins, and o-nitrochlorobenzene. Office of Toxic Snbstances, Report 560/2-76-005, 1976, 480 p. 

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