Surfactants, polyurethane

Although the above discussion details the chemistry of poly(alkylene oxide)s when used in the major applications of surfactants, polyurethane elastomers, RIM parts, and foams, there are a number of other end uses. Space constraints do not allow an in-depth discussion of these end uses, but the following examples are offered of the broad and interesting uses to which these polymers are put. 

Poly(propylene oxide) [25322-69-4] may be abbreviated PPO and copolymers of PO and ethylene oxide (EO) are referred to as EOPO. Diol poly(propylene oxide) is commonly referred to by the common name poly(propylene glycol) (PPG). Propylene oxide [75-56-9] and poly(propylene oxide) and its copolymers, with ethylene oxide, have by far the largest volume and importance in the polyurethane (PUR) and surfactant industry compared to all other polyepoxides. Articles reviewing propylene oxide (1), poly(propylene oxide) (2—4), other poly(aIkylene oxides) (4), and polyurethanes (5—7) are cited to lead the interested reader to additional detail not in the scope of this article. 

Sucrose acrylate derivatives can be converted into polymers and hydrogels that can be used as flocculants, water adsorbents, bioimplantables, and dmg dehvery devices (42). Sucrose ethers have appHcations as surfactants and surface coatings, and as feedstocks for synthesis of polyurethane foams and... 

Some of the chemicals used in the production of polyurethanes, such as the highly reactive isocyanates and tertiary amine catalysts, must be handled with caution. The other polyurethane ingredients, polyols and surfactants, are relatively inert materials having low toxicity. 

Cationic, anionic, and amphoteric surfactants derive thek water solubiUty from thek ionic charge, whereas the nonionic hydrophile derives its water solubihty from highly polar terminal hydroxyl groups. Cationic surfactants perform well in polar substrates like styrenics and polyurethane. Examples of cationic surfactants ate quaternary ammonium chlorides, quaternary ammonium methosulfates, and quaternary ammonium nitrates (see QuARTERNARY AMMONIUM compounds). Anionic surfactants work well in PVC and styrenics. Examples of anionic surfactants ate fatty phosphate esters and alkyl sulfonates. 

Surfactants used as lubricants are added to polymer resins to improve the flow characteristics of the plastic during processing they also stabilise the cells of polyurethane foams during the foaming process. Surfactants are either nonionic (e.g. fatty amides and alcohols), cationic, anionic (dominating class e.g. alkylbenzene sulfonates), zwitterionic, hetero-element or polymeric (e.g. EO-PO block copolymers). Fluorinated anionic surfactants or super surfactants enable a variety of surfaces normally regarded as difficult to wet. These include PE and PP any product required to wet the surface of these polymers will benefit from inclusion of fluorosurfactants. Surfactants are frequently multicomponent formulations, based on petro- or oleochemicals. 

The unique surface characteristics of polysiloxanes mean that they are extensively used as surfactants. Silicone surfactants have been thoroughly studied and described in numerous articles. For an extensive, in-depth discussion of this subject, a recent chapter by Hill,476 and his introductory chapter in the monograph he later edited,477 are excellent references. In the latter monograph, many aspects of silicone surfactants are described in 12 chapters. In the introduction, Hill discusses the chemistry of silicone surfactants, surface activity, aggregation behavior of silicone surfactants in various media, and their key applications in polyurethane foam manufacture, in textile and fiber industry, in personal care, and in paint and coating industries. All this information (with 200 cited references) provides a broad background for the discussion of more specific issues covered in other chapters. Thus, surfactants based on silicone polyether co-polymers are surveyed.478 Novel siloxane surfactant structures,479 surface activity and aggregation phenomena,480 silicone surfactants application in the formation of polyurethane foam,481 foam control and... 

Snow, S. A. Stevens, R. E. The Science of Silicone Surfactant Application in the Formation of Polyurethane Foam. In Silicone Surfactants-, Hill, R. M., Ed. Surfactant Science Series Dekker New York, 1999 Vol. 86, Chapter 5, pp 137-158. 

Industrially, silicone surfactants are used in a variety of processes including foam, textile, concrete and thermoplastic production, and applications include use as foam stabilisers, defoamers, emulsifiers, dispersants, wetters, adhesives, lubricants and release agents [1]. The ability of silicone surfactants to also function in organic media creates a unique niche for their use, such as in polyurethane foam manufacture and as additives to paints and oil-based formulations, whilst the ability to lower surface tension in aqueous solutions provides useful superwetting properties. The low biological risk associated with these compounds has also led to their use in cosmetics and personal care products [2]. 

In polymer applications derivatives of oils and fats, such as epoxides, polyols and dimerizations products based on unsaturated fatty acids, are used as plastic additives or components for composites or polymers like polyamides and polyurethanes. In the lubricant sector oleochemically-based fatty acid esters have proved to be powerful alternatives to conventional mineral oil products. For home and personal care applications a wide range of products, such as surfactants, emulsifiers, emollients and waxes, based on vegetable oil derivatives has provided extraordinary performance benefits to the end-customer. Selected products, such as the anionic surfactant fatty alcohol sulfate have been investigated thoroughly with regard to their environmental impact compared with petrochemical based products by life-cycle analysis. Other product examples include carbohydrate-based surfactants as well as oleochemical based emulsifiers, waxes and emollients. 

Polypropylene ether) polyol is the single most important product from propylene oxide and enjoys a predominant position in polyurethane applications. The ether linkages are very abundant in these polyols and they contribute to the physical and chemical properties in many applications such as surfactant action and hydrogen-bond formation. 

The aromatic polyols resulting from the reaction can be mixed with commercial polyols, blowing agents, surfactants, catalysts, and polymeric isocyanates to produce a rigid polyurethane foam. n compared w control foams produced from commercially available polyester polyols, the foams produced from reclaimed materials were found to have essentially the same properties. 

Polyurethane foam Natural oil polyol, water, and surfactants were weighed into a 1 quart metal cup and premixed for 15 seconds at 1800 rpm using a pin type mixer. The catalyst was added and the mixture stirred an additional 15 seconds at 1800 rpm. The polyisocyanate was then added and the mixture stirred at 2400 rpm for 3 seconds and immediately transferred to a 15 x 15 x 10 wooden box lined with a polyethylene bag. The buns were allowed to cure overnight before testing. 

Conducting composite polymer materials have also been prepared from the dispersed phase of concentrated emulsions. Polyurethane/polypyrrole composites [165] were obtained by blending an aqueous suspension of polypyrrole with a HIPE of a chloroform solution of polyurethane in aqueous surfactant... 

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