As the alkyl group of N-alkylated pyrrolidones is increased to CsP, surface-active p?operties become important. The resulting surfactant can interact synergistically with an anionic surfactant. This interaction is based on the electronegativity of the pyrrolidone carbonyl oxygen which can accept a proton to form a pseudoquaternary ammonium ion that can form an ion pair with large anions (i.e., anionic surfactants). The resulting ion pair is further stabilized by hydrophobic bonding between the two alkyl chains. In addition, pyrrolidone can electrostatically interact with aromatics, hydrogen-bond to nonionics, and, in essence, associate electrostatically/hydrophobically similarly to polyvinylpyrrolidone. This interaction of the pyrrolidone functional group can be transposed from one surfactant hydrophobe structure to another. This paper reviews the literature concerning the addition of pyrrolidone to a variety of hydrophobes of interest to both industrial and academic researchers. The chemistry of selected surface-active pyrrolidone derivatives, prepared from butyrolactone, aminoethylpyrrolidone, epoxypropylpyrrolidone, chloromethylpyrrolidone and itaconic acid, is reviewed. Pyrrolidone is a versatile substituent, capable of enhancing the performance of a variety of surfactant structures by improving water solubility, compatibility and solvency in a compact head group that favors surfactancy. In addition, the pyrrolidone ring, when incorporated into derivatives, usually reduces toxicity. JAOCS 72, 759-771 (1995).
The history of vinyl ether homopolymers has been more involved with the progress of polymer science than in the generation of highly successful commercial products. The reason appears to be economic, as less‐expensive monomers such as acrylic and vinyl ester types have dominated end‐use polymer technologies. Copolymers of methyl vinyl ether, especially with maleic anhydride, continue to be important in personal care and pharmaceutical markets. The polymerization of vinyl ethers, because of the strong electron‐donating oxygen, can be readily accomplished with cationic initiators to produce polymers and copolymers having the potential for significant variety. Only poly(methyl vinyl ether), however, achieved commercial success among the homopolymers, though its commercial importance has faded. Divinyl ethers are emerging as important ingredients in radiation‐cured coatings because they are more insensitive than acrylates to atmospheric oxygen present during cationic polymerization. Copolymers based on methyl vinyl ether/maleic anhydride, easily prepared by free‐radical initiation, continue to hold academic interest. The observation in 1949 that isobutyl vinyl ether can be polymerized with stereoregularity ushered in the stereochemical study of polymers, eventually leading to the development of stereoregular polypropylene. In fact, vinyl ethers were key monomers in the early polymer literature. Academic interest in living cationic polymerization and in the unusual compatibility of poly(methyl vinyl ether) with polystyrene continue to demonstrate that vinyl ether‐containing polymers are still valuable for contemporary interest.
From 174.0 g (1.0 mol) of dimethyl adipate there was obtained 87.0 g (70% yield) of distilled 3-ethyl-2-cyclopenten-2-ol-l-one of >99% purity according to vpc.
N ‐Vinyl lactams and their corresponding polymers and copolymers have received considerable attention in the academic literature and significant commercial success. However, until recently this interest centered on N ‐vinyl pyrrolidinone and its polymers and copolymers. N ‐Vinyl caprolactam is now emerging commercially because copolymerization with N ‐vinyl pyrrolidinone results in copolymers with high levels of lactam functionality but with controlled hydrophobicity desired in many hair‐fixative products designed to resist drop in high humidity environments. Polyvinylpyrrolidinone (PVP) is a unique water‐soluble polymer that forms lustrous, continuous films on dry‐down that are very adhesive because of hydrogen bonding to substrates such as skin and hair. This adhesive characteristic also results in a wide variety of useful applications such as pharmaceutical tablet binding, hot‐melt, and paper‐adhesive applications. PVP is relatively nontoxic and contributes mildness to formulations. PVP will also complex with a variety of small and large molecules because the pyrrolidinone carbonyl group can accept a proton in the presence of large anions, becoming pseudocationic. In addition, because of lactam polarity where significant charge can appear on the nitrogen and oxygen atoms, it can interact with electron‐rich aromatics. Ligands such as anionic dyes and surfactants or triiodide or phenolic or polynuclear aromatics or polyacids, etc, will interact and complex with PVP. PVPHI 3 or povidone–iodine is probably the most successful of these complexes, retaining a reservoir of iodine even in dilute solution, affording fresh germicidal iodine as free iodine is consumed. Cross‐linked PVP or crospovidone can be employed to remove bitter tannins (phenolics) from beer and wine. Dry crospovidone can be compressed because of interhydrogen bonding, only to rapidly swell when exposed to moisture. For this reason, it has achieved success as a tablet disintegrant.
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