Poly sulfone adhesives

Solvay Advanced Polymers. Udel Poly-sulfone Design Guide, Adhesive Bonding. bttp //www.solvayadvancedpolymers.com, 2010. 

Poly(vinyl acetate) emulsions can be made with a surfactant alone or with a protective coUoid alone, but the usual practice is to use a combination of the two. Normally, up to 3 wt % stabilizers may be included in the recipe, but when water sensitivity or tack of the wet film is desired, as in some adhesives, more may be included. The most commonly used surfactants are the anionic sulfates and sulfonates, but cationic emulsifiers and nonionics are also suitable. Indeed, some emulsion compounding formulas require the use of cationic or nonionic surfactants for stable formulations. The most commonly used protective coUoids are poly(vinyl alcohol) and hydroxyethyl cellulose, but there are many others, natural and synthetic, which are usable if not preferable for a given appHcation. 

For bioadhesive applications, anionic polymers appear to provide the most effective balance between adhesiveness and toxicity, with carboxylic materials preferred over sulfonic polymers [400]. Polyfacrylic acid) microparticles have been identified as particularly effective bioadhesive materials [402]. Studies with poly(acrylic acid) microparticles have indicated that, while water-swollen particles exhibit good bioadhesion, dry polymer particles give no adhesion at all. In addition, adhesive strength increases as the degree of ionization of the polymer is increased [402]. Thus the expanded nature of the polymer network is important to mucoadhesion, probably via polymer interdiffusion and entanglement with mucin [403],... 

A similar study was undertaken by Beck Tan et al. on the adhesion between poly(styrene-r-sulfonated styrene) and poly(2-vinylpyridine). In this case, however, the variable was the mole fraction of sulfonated styrene in the random copolymer [95]. The results of the maximum fracture toughness Qc vs. mole fraction of functional groups are plotted in Fig. 51. The reinforcement shows a very sharp maximum with degree of functionalization consistent with the multiple stitching giving rise to short loops poorly entangled with the homopolymer however, in this case as well, the bulk properties of PS are modified by the presence of the styrenesulfonic acid and this could contribute to the decrease in Qc at high levels of functionalization. 

Flexible printed wiring laminates usually contain (but are not limited to) either a polyimide or a polyester [usually poly(ethylene terephthalate)] with copper conductors. These laminates are prepared in sheets or by roll-to-roll lamination, usually by means of an adhesive. Alternatively, direct fusion without an adhesive is used. Recent developments include the use of alternative substrate materials such as poly(ether sulfones), additive plating of copper, and casting of a polymer directly on the copper foil web. 

Practical consequences of Eg modification in polymer films include significant changes of dissolution, diffusional and etching characteristics, mechanical creep behavior, and adhesion. Figure 17.30 shows a plot of the effective diffusion coefficient of perfluorooctane sulfonate photoacid as a function of film thickness of partially protected poly(4-t-butyloxycarbonyloxstyrene). The profile shows asymptotic behavior at 600 A, below which diffusion slows down remarkably, probably due to interfacial and confinement effects. Clearly, the interaction of the first few hundred angstroms of the film with the substrate determines its adhesion and can alter its electrical and optical properties as well as its topographical and surface characteristics. ... 

Bouchard [161] developed a poly(vinyl acetate) adhesive formulation using hydrogen peroxide-zinc formaldehyde sulfoxylate as the initiator system, poly-(vinyl alcohol) and sodium decylbenzene sulfonate as the emulsification system, and lauryl peroxide dissolved in the seed monomer to reduce the viscosity of the final latex (see Table XVIII). To this, from separate streams, a hydrogen peroxide solution, a sodium bicarbonate solution, and vinyl acetate are added. The final latex had a pH of 4.5 and a viscosity of 7 cP at 25°C. 

Alkali and acid treatments have also been used to modify surface properties of polymers sulfonated polyethylene films treated first with ethylenediamine and then with a terpolymer of vinyhdene chloride, acrylonitrile, and acrylic acid exhibited better clarity and scuff resistance and reduced permeabihty. Permanently amber-colored polyethylene containers suitable for storing light-sensitive compoimds have been produced by treating fluorosulfonated polyethylene with alkali. Poly(ethylene terephthalate) dipped into trichloroacetic/chromic acid mixture has improved adhesion to polyethylene and nylons. Antifogging lenses have been prepared by exposing polystyrene films to sulfonating conditions. Acid and alkali surface treatments have also been used to produce desired properties in polymethylmethacrylates, polyacrylonitrile, styrene-butadiene resins, polyisobutylene, and natural rubber. Surface halogenation of the diene polymers natural rubber and polyisobutylene resulted in increased adhesion to polar surfaces. 

A. Ayambem, S. J. Mecham, Y. Sun, T. E. Glass, and J. E. McGrath. End-group substituent effects on the rate/extent of network formation and adhesion for phenylethynyl-terminated poly(arylene ether sulfone) oligomers. Polymer, 41(13) 5109-5124, June 2000. 

Bowen et al. [39] measured directly the adhesion (interaction) of cellobiose and cellulose with two polymeric UF membranes of similar MWCO, but of different materials. As probes, they used silica spheres (diameter 5-8 im) the surfaces of which were modified by static adsorption of cellobiose. They also used pure cellulose probes. Membrane ES 404 was made of poly(ether sulfone) alone, and EM 006 was made of a poly(ether sulfone)-polyacrylate blend, chosen specifically to increase the hydrophihc properties and decrease the fouling properties of the membrane. Study of ES 404 and EM 006 had shown that the interaction of cellobiose or of colloidal cellulose with the membranes was such that ES 404 always had the greater adhesion and greater fouling tendency. However, if the membrane was first fouled with cellobiose, the colloidal cellulose adhesion force was increased significantly, and the differences between the membranes diminished. Bowen et al. suggested that in the future, it would be possible to use the techniques developed to allow prior assessment of the fouUng propensity of process streams with different types of membranes. 

Bowen et al. [40] used sulfonated poly(ether ether ketone) (SPEEK) as an additive in the polysulfone (PSf)/SPEEK/N-methyl-2-pyrrolidone (NMP) system. Membrane characterization was carried out using filtration studies and AEM. Membranes prepared from solutions in the region of polyelectrolyte behavior [41] showed more pronounced and systematic improvement of membrane permeability and salt rejection. A small decrease in pore size and surface roughness was also followed by an increase in SPEEK content. Compared with a - 28.5 mN m adhesion force of a 4 pm silica particle for a SPEEK free PSf membrane, a SPEEK modified membrane showed greatly reduced adhesion of - 0.75 mNm h This, together with the surface smoothening effect, leads to the reduction of membrane fouling when the surface is modified by the addition of SPEEK. 

Poly(sulfides) are mainly used for adhesives, coatings, and sealants, because they are easily crosslink-able, even at room temperature. Functional groups and building blocks of poly(ether sulfone) (PES) and related compounds are shown in Figure 7.1. 

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