Copolymerisable surfactant

Copolymerisable surfactants are available for emulsion polymerisation systems. These are amphoteric molecules containing a reactive double bond. By participating in the polymerisation they improve the resistance of the final coating to water and attack by aqueous solutions. 

PolyHIPE materials have also been prepared by polycondensation in high internal phase emulsions [153]. Thus, a resorcinol-formaldehyde (RF) porous copolymer was synthesised from an o/w HIPE of cyclohexane in an aqueous solution of resorcinol, formaldehyde and surfactant. Addition of an acid catalyst to the emulsion, followed by heating, resulted in copolymerisation. Other systems prepared included urea-formaldehyde, phenol-formaldehyde, melamine-formaldehyde and a polysiloxane-based elastomeric species. 

Polymers can be emulsified in water to produce coatings which, once chlorinated, act as contact disinfectants. These coated surfaces efficiently inactivate microbes within relatively brief contact times, i.e., several minutes. Antimicrobial latexes can be formed via the copolymerisation of an N-halamine precursor monomer with other monomers in water, in the presence of a surfactant, or by chemically grafting the N-halamine precursor monomer onto an emulsified polymer backbone, followed by chlorination. 

Yoon etal)- reported the synthesis of mesoporous carbon using as-synthesised MCM-48 silica/surfactant mesophase as the template, followed by introduction of carbon precursor (divinylbenzene), carbonisation and removal of silica. Hyeon and co-workers " reported the synthesis of mesoporous carbon by the carbonisation of composites containing silica, P123 triblock copolymer and phenol resin, followed by removal of silica. The synthesis was achieved by treating the as-synthesised silica/triblock copolymer nanocomposite with sulfuric acid to crosslink the triblock copolymers followed by carbonisation. " Kim et al. reported the synthesis of carbon nanotubes using PI 23 surfactant inside mesoporous silica, although ordered arrays of carbon nanotubes were not observed.Kawashima et al. synthesised mesoporous carbon via copolymerisation of tetraethoxysilane (TEOS) and furfuryl alcohol. 

Biodegradable plastic foams were synthesised by free radical initiated copolymerisation between maleated castor oil and diluent monomer styrene in the presence of free radical initiator (3 phr (parts per 100 of resin) BPO), accelerators (0.3 phr A,A-dimethylaniline or 3 phr cobalt naphthe-nante), surfactant (2 phr) and blowing agent (NaHCOs) in a mould at 60°C followed by addition of 45 phr of water. The prepared foam was post-cured at 100°C for 2 h. 

Copolymerisation of these macromonomers with norbomene or norbomene acetate has yielded a series of poly(norbomene)-graft-poly-(e-caprolactone) copolymers of well-defined structures. Furthermore, PCL macromonomers were also homopolymerised in high yield into high molecular weight comb chains of narrow molecular weight distribution MJM =1.10). Such copolymers have potential applications as surface modifiers, polymeric surfactants, compatibilisers in polymer blends, and dispersion stabilisers. 

Latices of PVAc, copolymers of vinyl acetate and acrylamide and copolymers of methyl methacrylate and butyl methacrylate were synthesised by free-radical polymerisation or copolymerisation using different ionic or non-ionic surfactants and protective colloids. The effects of the amount of surfactant, copolymer composition and quantity of monomers on the particle size of the latex were examined and the use of the latex obtained from the methyl methacrylate-butyl methacrylate copolymer as an ink on PP syringes and of the PVAc latex with various amounts of epoxy resin as an adhesive for wood evaluated. 7 refs. 

Surfmers , i.e. surfactants which also acted as copolymerisable monomers, were synthesised from the hemi-ester of a fatty alcohol and maleic anhydride and were then used in the preparation of self-crosslinking dispersions by seeded semi-continuous emulsion polymerisation of acrylate monomers. Water-borne exterior wood stains were prepared from the dispersions and their properties were studied. The use of surfmers as sole emulsifiers in emulsion polymerisation was considered and data were obtained on the effects of surfmers on film formation, water barrier properties, gloss retention and mechanical properties. Environmental aspects of the use of products involving surfmers were examined. 6 refs. 

Details are given of the preparation of SAN latexes by micro-emulsion polymerisation using sodium dodecyl sulphate as an anionic surfactant. Kinetics of copolymerisation was studied at different temperatures using different concentrations of potassium persulphate and hydrogen peroxide/ascorbic acid. The latexes were characterised for particle size and number of particles by dynamic light scattering and TEM. Products were examined using NMR and thermal analysis. 20 refs. INDIA... 

Polymerisable styrenic surfactants (surfmers) and non-reactive analogues were applied in emulsion copolymerisation of acrylic monomers in a seeded semi-... 

Latex particles bearing carbohydrate species were prepared by emulsion copolymerisation of styrene or methyl methacrylate with polymerisable liposacchaiide surfactants. Surface active and mesomorphic properties are discussed. Data are given concerning the adsorption of bovine serum albumin and the covalent binding of antibodies and singlestrand DNA fragments on their surface. 27 refs. 

No.17, Dec.1997, p.3837-46 ROLE OF NONIONIC SURFACTANT TRITON X-405 IN EMULSION POLYMERISATION. III. COPOLYMERISATION OF STYRENE AND BUTYL ACRYLATE... 

The preparation of a synthetic latex is shown to be a very complex process that is affected by the monomers selected, surfactants, initiators and the polymerisation process. The semi-continuous process is the one most frequently used as it provides control of the polymerisation heat removal, as well as control of the composition of the copolymers comprising several types of monomer units. Some aspects of copolymerisation in emulsion and particle growth in the case of the semi-continuous process are discussed. The copolymers usually comprise 4 to 5 comonomers, some of them with functional groups. The functional groups serve as loci for crosslinking, improve colloid stability, increase polarity, improve adhesion and cause alkali-solubility and/or alkali swellability. High value polymer latices with special particle morphology, composition and other... 

Now consider the case of polymerisation of monomers with appreciable water solubility and their copolymerisation with less water-soluble comonomers. Monomers such as vinyl acetate or methyl acrylate have sufficient water solubility to permit their rapid polymerisation in the water phase even in the absence or after the disappearance of surfactant micelles. New polymer particles can be formed as long as the monomer concentration in the water phase remains high enough. In most cases, there is strong monomer/polymer affinity so that more and more monomer will be extracted from the water phase. As polymer concentrations increase, polymerisation in the water phase will finally cease and with it the formation of new particles. Henceforth, conversion will proceed at the surface of the polymer/monomer particles in much the same way as in the case of water-insoluble monomers after the disappearance of the surfactant micelle. 

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