Polymers interactions with surfactants

Polymers Interact with surfactants and mlcroemulslons In diverse. Interesting and technologically Important wavs(1.21. The mechanisms that are responsible for the Interactions Include the usual panoply of forces Involved In the interaction of any two different molecules lon-lon, lon-dlpole, dlpole-dlpole, and van der Waals forces all modulated by the presence of solvent and/ or other species such as dissolved salts. All may play a role. The special factors Involved in surfactant/polymer and polymer-/mlcroemulslon Interactions that form the basis for their particular interest lies in their tendencies to form a variety of supermolecular clusters and conformations, which In tuim may lead to the existence of separate phases of coexisting species. Micelles may form In association with the polymer, polymer may precipitate or be solubilized, mlcroemulslon phase boundaries may change, and so on. 

A class of systems extensively investigated by means of PFG-NMR are colloids. They are usually hydrophobically modified water-soluble polymers, that is, polymers with a water-soluble skeleton bearing one or more hydrophobic units, which allow the self-assembling of the polymer in water solution and the interaction with surfactants.77... 

Early oxidation hair dyes were used in solution form these have been replaced by cream- or gel-based formulas. The oil-in-water emulsions commonly used can be supplemented with auxiliary ingredients, such as polymers to improve combing ability, as well as other conditioning additives. Extensive patent literature is available on this point [35], Gel formulations may be based on alcoholic solutions of nonionic surfactants or fatty acid alkanolamide solutions, which form a gel when mixed with the oxidant. The type (emulsion or gel) and the basic composition of the preparation strongly influence dyeing [47], Different base formulations with the same dye content yield varying color depths and shading due to the distribution of the dye between the different phases of the product, interaction with surfactants, and diffusion from the product into the hair. 

Now consider the problems which occur In the surfactant field, e.g. In detergency, cosmetics or pharmaceuticals, where polymers are usually associated with detergents to control the surface activity of the formulations (17). In these systems the polymers are known to Interact with surfactant micelles or mlcroemulslon droplets the Interaction can be beneficial, but most often It Is a real nuisance. 

An intramolecular structure is also formed in polymers when these interact with surfactants (Table 14). These changes in polymers by the action of S may be... 

Effects of reaction products on other transport phenomena Interactions with surfactant and polymer if they are injected... 

Several recent patents describe the benefits of polymers in LDLDs (Table 7.15). Polymers are well known to interact with surfactants and provide many interesting properties. Some of the benefits claimed in the patents summarized in Table 7.15 are soil resistance due to amino acid copolymers, polyethylene glycol as a grease release agent, increased grease removal from polyoxyethylene diamine, enhanced foam volume and duration, increased solubility, and enhanced mildness by ethylene oxide-propylene oxide copolymers. As described in these various patents, the addition of polymers to LDLDs can aid performance in many important attributes of the product. 

Hydrophobically modified water-soluble polymers (HMWSPs) exhibit enhanced solution viscosity and unique rheological properties. These properties can be explained in terms of intermolecular associations via hydrophobes. This chapter describes the synthesis and solution properties of HMWSPs, Particularly discussed are the solution properties of hydrophobically modified hydroxyethytjcellulose (HMHEC) in aqueous and surfactant systems, HMHECs interact with surfactants and thus modify solution viscosities. The structure and the concentration of the surfactant dictate the solution behavior of HMHEC. The unique solution properties of HMHEC can be exploited to meet industrial demands for specific formulations or applications. 

The first question in this treatment is the meaning of the polymer-active center. The polymer chain contains many centers available for interaction with surfactant. Insofar as the centers are identical and indistinguishable, the polymer-surfacttmt complex formation can be treated as a multiple chemical equilibrium ... 

In the last years large attention was devoted to the synthesis and characterization of SBA-16 material focusing the interest on the formation mechanisms of copolymer micelles which drive the organization of the final siliceous mesostructure. In this framework, the physico-chemical properties at the interface between silica and triblock E0106P070E0106 co-polymer in a SBA-16 material were investigated. In particular, the combination of IR spectroscopy with SS NMR allowed to obtain complementary information on how the surfactant co-polymer interacts with the SBA-16 surface silanols in the presence or absence of physisorbed water and to follow the evolution of the structural organization of the co-polymer, which depends on the hydration degree of the SBA-16 sample. 

The preparation of metal organosols by electrolysis in a two-layer bath proved to be more suitable than electrochemical polymerization. The upper organic layer of the electrolytic bath is a dilute solution of a polymer in an orgaific solvent, sometimes, supplemented with a small amormts of surfactant. The polymer interacts with the nascent colloidal metal particles near the interface between layers. 

The body of the text consists of 12 self-standing chapters comprising a mix of the fundamental science of polymers, their solution and interfacial properties, their interactions with surfactants, the intrinsic properties of polymers employed in cosmetic formulations, and the properties they confer to treated surfaces. There is also an appendix which lists and groups the polymers used in cosmetics. 

While hydrophobically modified nonionic polymers are encountered far less frequently than their ionic counterparts, one can find several fluorescence studies of their interaction with surfactants. These include investigations of the HM-HEC/SDS system by Dualeh and Steiner (100) and by Sivadasan and Somasundaran (117) of the same polymer with added SDS and also the nonionic surfactant CnEOg. A comprehensive study. 

Finally, by way of illustration, we mention a polymer type currently receiving much attention. The polymer is referred to as hydrophobically modified ethoxylated urethane (HEUR), the reaction product of a PEG and a diisocyanate, end-capped with a long chain alcohol or amine. HEURs are already recognized as having much potential as associative thickeners in coating formulations. Their structure suggests they will show pronounced interaction with surfactants in solution and this is indeed the case. Here we refer to two recent studies. The first by Hulden (95) included surface tension studies of the polymer... 

Kastner U, Hoffmann H, Donges R, Ehrler R. A comparison of several samples of modified hydroxethyl cellulose and their interactions with surfactants. Prog Colloid Polym Sci 1995 98 57-62. 

A, Polymer molecule does not interact with surfactants for electrostatic or steric reasons. No surfactant is bound to the polymer. For example, the surfactant and the polymer are both anionic or both cationic... 

An intramolecular structure is also formed in polymers when these interact with surfactants (Table 14). These changes in polymers by the action of S may be utilized for studies on intermolecular interactions in the polymer-S system. Only the polymer with bound S ions exhibits a lower IMM than does the original polymer. On the other hand, only those surfactants, that change the IMM of the polymer, come into prolonged (>10 s) contact with the polymer The Pi method was applied to a comparative investigation of the IMM of a copolymer of vinylamine (10%) with... 

PER Persson, K., Wang, G., and Olofsson, G., Self-diffusion, thermal effects and viscosity of a monodisperse associative polymer self-association and interaction with surfactants, J. Chem. Soc., Faraday Trans., 90, 3555, 1994. 

Stimuli responsiveness includes conformational and thermodynamic phase transitions (e.g., lower critical solution temperature [LCST]), aggregation, abihty to encapsulate and release other agents (e.g., drugs), abihty to interact with surfactants, other polymers, etc. StimuU producing these responses include tanperature, light, pH, ionic strength, specific small molecules, surfactants, solvent type and mixtures, etc [104-109]. 

Adsorption experiments conducted with PEO and alumina particles showed no adsorption of the former on the particles. Because it is known that SDS adsorbs on alumina and that PEO interacts with SDS, PEO adsorption tests were repeated with alumina pretreated with SDS. The authors observed that the presence of a surfactant on the alumina surface caused near-complete adsorption of the polymer as a consequence of its interaction with surfactant aggregates. This result showed that it was possible to force the adsorption of a polymer on a solid surface on which it spontaneously does not adsorb. Instead of drastically modifying the solid-surface properties to force the adsorption of PEO, it seems, by far, more convenient to form surfactant aggregates at the solid-liquid interface and then to allow the polymer to adsorb. 

When a highly swollen polyelectrolyte gel is immersed in an aqueous solution of a surfactant, the volume of the gel suddenly shrinks. Further, if a hydrophobic gel that does not swell in water is placed in the same solution, the gel swells. These phenomena are caused by the adsorption of the surfactant onto the gel. The adsorption of the surfactant onto the gel is caused by static interaction (when it is a polyelectrolyte gel) or hydro-phobic interaction. Gels can change from hydrophilic to hydrophobic and vice versa by interacting with surfactant molecules. As a result, the properties of the gel change drastically. There are many reports on the interaction between surfactants and linear polymers [26-29]. A Russian group reported on work on three-dimensionally crosslinked polymer gels [30-32], Later, other authors developed a worm-like device that moves... 

Figure 7.5. A schematic model for the interaction of charged polymer chains with surfactants of opposite charge.

---