Resins solubility parameters

Qualitatively, accessibility to active centers has been related to the medium solubility parameter, 5m, and reaction rates depend on the number of accessible active centers [2]. The near the 5m value to that of the resin solubility parameter (5p) is, the higher the affinity resin-medium is. In the present system, the solubility parameter value of an IB-MeOH medium increases with the methanol content. In example, at 60°C the 5 values for IB and MeOH are, respectively, 12.04 10 and 27.78 10 (J/m"). ... 

The inclusion of TfSm) in the kinetic equation implies the introduction of one new parameter to fit, related to the resin solubility parameter, at each temperature. It has been observed a smooth lineal dependence of 6m with the temperature. By analogy, 6p should show also this kind of temperature dependence. 

Table 7.7 Solvent-Resin Solubility Parameter Worksheet... 

Solubility Parameter. CompatibiHty between hydrocarbon resins and other components in an appHcation can be estimated by the Hildebrand solubiHty parameter (2). In order for materials to be mutually soluble, the free energy of mixing must be negative (3). The solubiHty of a hydrocarbon resin with other polymers or components in a system can be approximated by the similarities in the solubiHty parameters of the resin and the other materials. Tme solubiHty parameters are only available for simple compounds and solvents. However, parameters for more complex materials can be approximated by relative solubiHty comparisons with substances of known solubiHty parameter. 

Table 1. Solubility Parameter Ranges for Some Commercial PVF and PVB Resins ...

The conventionally covalently cross-linked rubbers and plastics cannot dissolve without chemical change. They will, however, swell in solvents of similar solubility parameter, the degree of swelling decreasing with increase in cross-link density. The solution properties of the thermoelastomers which are two-phase materials are much more complex, depending on whether or not the rubber phase and the resin domains are dissolved by the solvent. 

Acetal homopolymer resins show outstanding resistance to organic solvents, no effective solvent having yet been found for temperatures below 70°C. Above this temperature some phenolic materials such as the chlorophenols are effective. Stress cracking has not been encountered in organic solvents. Swelling occurs with solvents of similar solubility parameter to that of the polymer (8 = 22.4 MPa ). 

Being cross-linked, the resin will not dissolve without decomposition but will be swollen by liquids of similar solubility parameter to the cured resin. The chemical resistance is as much dependent on the hardener as on the resin since these two will determine the nature of the linkages formed. The acidic hardeners form ester groups which will be less resistant to alkalis. 

Extensive use of the three-dimensional solubility parameters for predicting adhesion seems not to have been made, although its additional flexibility should make it successful over a wider range of conditions than the single-parameter approach. Some recent studies involving dental adhesion employed the method with success. Asmussen and Uno fl40 successfully correlated the shear bond strength of various dental adhesive resins, characterized in terms of their three-... 

Solubility of resins can be predicted in a similar way as for the solubility of polychloroprene rubbers in a solvent mixture (see Section 5.5) by means of solubility diagrams (plots of the hydrogen bonding index (y) against the solubility parameter (5). Another more simple way to determine the solubility of resins is the determination of the cloud point, the aniline and the mixed aniline points. 

Hansen CM (1967) The three-dimensional solubility parameter - Key to paint component affinities I. Solvents, polymers, and resins. J Paint Technol 39 104... 

Table VII summarizes the solubility parameters of MEK, the CTBN elastomers, and an epoxy resin of similar EEW.

Prior to the introduction of the solubility parameter (solpar) concept, paint chemists used Kauri butanol values, mixed aniline points, and heptane numbers to predict the solubility of resins in aliphatic solvents. These parameters have been replaced, to a large extent, by solpars, but heptane numbers are still used, and these empirical parameters can be converted to solpar values. 

PMA is a tough leathery resin with a low Tg and a solubility parameter of 10.5 H. In polymers of alkyl acrylates the solubility parameter decreases as the size of the alkyl group increases. The flexibility also increases with the size of the pendant groups but because of side chain crystallization this tendency is reversed when the alkyl group has more than ten carbon atoms. Polyalkyi acrylates are readily hydrolyzed by alkalis to produce salts of polyacrylic acid. The copolymer of ethyl acrylate (95%) and chloroethyl vinyl ether (5%) is a commercial oil-resistant elastomer. 

FBZ precursor and can therefore be attributed to the segregated PFPE moiety. This kind of behavior is quite general for copolymers containing PFPE macromers and also in the Z1072 and Z1073 resins themselves. The driving force is the relevant difference in solubility parameters between fluorinated and nonfluorinated macromers, since the cohesive energy density (CED) of the perfluorocopolyethers is one of the smallest known. ... 

One approach that was considered is based upon the solubility parameter theory of Hildebrand and Scott (36, 37). This approach attempts to determine the best solvent for cleaning resins as a function of the known resin contaminants. Hildebrand and Scott (36, 37) developed the solubility parameter (6) to describe the property of solvents ... 

Table IV. Solubility Parameters for Selected XAD Resin Artifacts...

Table IV shows the calculated solubility parameter (38) of some of the resin contaminants from Table III. The average total solubility parameters for the XAD-2 and XAD-8 organic contaminants (Table IV) are approximately the same. However, there are differences between XAD-2 and XAD-8 for the average hydrogen bonding and average nonpolar components of the solubility parameter.

Table V lists the common solvents used for cleaning XAD resins and their respective solubility parameters. Methanol and acetonitrile [which are used in the cleanup procedure of Junk et. al. (5)] have very different total solubility parameters than the compounds listed in Table IV. Thus, they should be less efficient for eluting the resin contaminants from the resin polymers. This situation explains the GC profile results, which show large numbers and high concentrations of contaminants after the successive 24-h Soxhlet extractions using methanol, acetonitrile, and ethyl ether (Figure 2).

Table V. Solubility Parameters of Resin Cleanup Solvents...

It is known that most mixtures of elastomers and resinous copolymers are rather polydisperse, their incompatibility giving rise to poor interfacial adhesion. Preferably, a resinous monomer or monomers are grafted to the rubber, and they act as a link between the rubber and the resin phases. As Rosen (13) has pointed out, one means of predicting the affinities of polymer pairs from measurable properties is through the use of the solubility parameter, and this has proved useful in this study. The solubility parameter concept was originally derived from the thermody-... 

The acrylic elastomers were graft copolymerized and either investigated in that form or blended with resins having matching refractive indices and suitable solubility parameters. Compositional homogeneity was maintained using techniques similar to those outlined in the first paper (3). 

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