Robert Y. Lochhead

An investigation of the mechanism by which hydrophobically modified hydrophilic polymers act as primary emulsifiers for oil-in-water emulsions 1. Poly(acrylic acids) and hydroxyethyl celluloses

Abstract Pseudophase diagrams for the system cyclohexane-water-polymer were constructed and the compositional regions of emulsion stability and coalescence were identified. The polymeric stabilizers investigated were hydrophobically modified poly(acrylic acid) (HMPAA), hydrophobically modified hydroxyethyl cellulose (HMHEC) and analogous poly(acrylic acid) (PAA) and hydroxyethyl cellulose (HEC) as controls. The critical overlap concentration c * of these polymers and their interfacial activities at the cyclohexane/water interface were determined. In the case of the acrylic acid polymers, c * varied with pH but a critical condition for emulsion stability appeared to be the c * value of the unneutralized polymer ( c * UN ). It was found that when HMPAA was incorporated as the emulsifier the emulsions coalesced when the pH was greater than 6.5 and simultaneously the HMPAA concentration was less than c * UN . The emulsions were stable above c * UN at all pH values and below pH 6.5 when the polymer concentration was less than c * UN . On the basis of these results, it is postulated that stabilization in the lower concentration range occurs by an electrosteric stabilization mechanism and in the upper concentration range by trapping the discrete oil droplets in a continuum of hydrophilic polymer segments. PAA stabilizes only below pH 6.5 and below c * UN . Both HMHEC and HEC are ineffective below c * and only HMHEC is effective as an emulsifier above c *.

Interactions of aminoalkylcarbamoyl cellulose derivatives and sodium dodecyl sulfate. 2. Foam stabilization

Abstract We have compared the interactions between polyquaternium 10 and sodium dodecyl sulfate with similar complexes of mono and diquaternary ammoniumalkylcarbamoyl cellulose derivatives by measuring the foaming efficiency and foam stability of their aqueous solutions. At approximately a 1:1 stoichiometric ratio of sodium dodecyl sulfate (SDS) to quaternary groups, an insoluble precipitate began to form. Maximum foamability and foam stabilization were observed in systems close to the 2 dimensional phase boundary between soluble polymer–surfactant complexes and insoluble complexes. Foaming studies indicated that for a given amount of sodium dodecyl sulfate, the most kinetically stable foam was obtained using a monoquaternary polymer. The addition of a second cationic charge on the grafted polymer substituents apparently destabilized the foam.

Cosmetic nanotechnology : polymers and colloids in cosmetics

This symposium series book will tackle one of the fastest growing markets in the chemical industry in the US and world wide: personal care. Through advances in nanotechnology there have been significant opportunities for new developments in materials and delivery mechanisms for cosmetics and personal care products. This book will address the commercially important ingredients and delivery technologies used in cosmetic nanotechnology: polymers and colloids. Since more than half of the contributors are industrial researchers providing a perspective on real-life applications of personal care ingredients, the coverage of this topic will not only be comprehensive, but thoroughly undertake much needed concerns regarding research and development topics in cosmetic nanotechnology.

The Synthesis of Hydrophobically Modified Water-Soluble Polyzwitterionic Copolymers and Responsiveness to Surfactants in Aqueous Solution

Abstract A novel zwitterionic surfactant monomer containing a carboxybetaine moiety and a 10 carbon aliphatic tail was synthesized and copolymerized with acrylamide to yield a water‐soluble, hydrophobically modified zwitterionic polymer [Poly(acrylamide‐co‐(3‐(N,N‐dimethyl‐N‐3′‐(N′‐acryloyl)aza‐tridecyl) ammonio butanoate))]. The response of aqueous polymer solutions to the addition of various classes of surfactant was investigated and compared to that of an analogous novel polymer containing the sulfobetaine zwitterion [Poly(acrylamide‐co‐(N,N‐dimethyl‐N‐3′‐(N′‐acryloyl) aza‐tridecyl) ammonio propane sulfonate))]. It was found that the addition of sodium dodecyl sulfate (SDS) produced a pronounced maximum in viscosity, while dodecyltrimethylammoniumbromide (DTAB), N‐dodecyl‐N,N‐dimethylammonio‐1‐propanesulfonate (SB3‐12), and Triton X‐100 either had no effect, or produced a decrease in viscosity. The effect of pH on polymer–SDS interaction was also studied. Lowering pH increased the SDS–polymer interaction and significantly shifted viscosity enhancement to a higher SDS concentration. #Paper Number 108 in a series entitled Water Soluble Polymers.

Anti-Deposition Agents to prevent Spilled Oil from Fouling the Coastal Environment and Ecology

Following the recent Deepwater Horizon incident in the Gulf of Mexico, more than one million gallons of dispersant was deployed to the site of the spilled oil. The clean-up strategy in this case wa...

The Investigation of the Effects of Polyelectrolyte Attributes on Complex Coacervate Properties using High-Throughput Formulation and Characterization Techniques

Formulators of complex mixtures have long known that the characteristics of their final formulation and the position of “equilibrium” often depends critically upon the order of addition of ingredients and the precise processing conditions under which the formulation was made. The large variety of possible outcomes derive from the many eigenstates that are available to each composition of a complex mixture due to the fact that the bonds between the component molecules are weak physical bonds and therefore a potential multitude of nanostructures can be formed. This is especially true of systems comprising polyelectrolytes and oppositely charged surfactants in the semi-dilute regime, because both polyelectrolyte conformation and surfactant micellar association structures are strongly influenced by the ionic environment of the polymer and surfactant molecules. This is especially important for 2-in-1 shampoos that depend upon the spontaneous creation of a polyelectrolyte/surfactant coacervate to deposit active conditioning, styling or antidandruff ingredients during the shampoo process. The investigation of the effects of order of addition requires exanimation of a myriad of samples and it is virtually impossible by conventional techniques. This task is ideally suited to investigation by a combinatorial approach aimed at the generation of libraries of pseudo-phase diagrams. In this study we developed a high-throughput screening method to generate phase diagrams over a large range of concentrations for cationic polysaccharide interaction with anionic surfactant in the presence and absence of dissolved electrolyte. Using a liquid handling system for sample preparation, we are able to analyze nearly 1000 samples per day, making the above goals of understanding electrolyte effects and coacervate structure-property relationships attainable.