Adhesion to polymer surfaces

Tamada Y, Ikada Y (1993) Effect of preadsorbed proteins on cell adhesion to polymer surfaces. J Colloid Interface Sci 155 334-339... 

While pursuing the practical objective already mentioned, we also hoped that the synthesis of well-characterized polymers carrying bound antiplatelet agents would faciltate due study of factors influencing platelet adhesion to polymer surfaces. 

Speranza G, Gottardi G, PederzoUi C, et al. Role of chemical interactions in bacterial adhesion to polymer surfaces. Biomaterials May 2004 25(ll) 2029-37. 

Lee, J.H., Lee, S J., Khang, G., Lee, H.B., 2000. The effect of fluid shear stress on endothelial cell adhesiveness to polymer surfaces with wettability gradient. J. Colloid Interface Sci. 230, 84-90. 

Priming is used to promote adhesion to polymer surfaces. Primed PET is a widely used industrial material which ATR-EllR has difficulty in characterising due to the number and intensity of the absorption bands of the PET substrate. Primer species were identifled as PMMA, poly(ethylacrylate) and poly(caprolactone) by ToF-SIMS from characteristic fragments [190]. As also PET fragment ions were observed the primer layer is either extremely thin (<10 A) or discontinuous. 

Sihcones (qv) have an advantage over organic resias ia their superior thermal stabiUty and low dielectric constants. Polyurethanes, when cured, are tough and possess outstanding abrasion and thermal shock resistance. They also have favorable electrical properties and good adhesion to most surfaces. However, polyurethanes are extremely sensitive to and can degrade after prolonged contact with moisture as a result, they are not as commonly used as epoxies and sihcones (see Urethane polymers). 

Cyanoacrylate adhesives cure by anionic polymerization. This reaction is catalyzed by weak bases (such as water), so the adhesives are generally stabilized by the inclusion of a weak acid in the formulation. While adhesion of cyanoacrylates to bare metals and many polymers is excellent, bonding to polyolefins requires a surface modifying primer. Solutions of chlorinated polyolefin oligomers, fran-sition metal complexes, and organic bases such as tertiary amines can greatly enhance cyanoacrylate adhesion to these surfaces [72]. The solvent is a critical component of these primers, as solvent swelling of the surface facilitates inter-... 

Other polymers used in the PSA industry include synthetic polyisoprenes and polybutadienes, styrene-butadiene rubbers, butadiene-acrylonitrile rubbers, polychloroprenes, and some polyisobutylenes. With the exception of pure polyisobutylenes, these polymer backbones retain some unsaturation, which makes them susceptible to oxidation and UV degradation. The rubbers require compounding with tackifiers and, if desired, plasticizers or oils to make them tacky. To improve performance and to make them more processible, diene-based polymers are typically compounded with additional stabilizers, chemical crosslinkers, and solvents for coating. Emulsion polymerized styrene butadiene rubbers (SBRs) are a common basis for PSA formulation [121]. The tackified SBR PSAs show improved cohesive strength as the Mooney viscosity and percent bound styrene in the rubber increases. The peel performance typically is best with 24—40% bound styrene in the rubber. To increase adhesion to polar surfaces, carboxylated SBRs have been used for PSA formulation. Blends of SBR and natural rubber are commonly used to improve long-term stability of the adhesives. 

The structure of the isobutylene-derived polymers is hydrocarbonaceous and is non-polar, so poor adhesion to many surfaces is obtained. The addition of polar resins may improve adhesion. 

Even if a same azide is used as the sensitizer, such properties of the photoresist as photosensitivity, photocurability and adhesion to base surfaces differ depending on the property of the base polymer. That is, degree of cyclization, content of the unsaturated groups and molecular weight of the polymer affect the photoresist properties mentioned above. H.L.Hunter et al. have discussed the dependence of the sensitivity of polybutadiene photoresist on the polymer structure, and have concluded that a higher sensitivity was obtained when 1,2- and 3, -isomers were used( 7.) ... 

Fig. 8.10 The porous structure and high specific surface of CNT fibers enhances adhesion to polymer matrices (a) shows the cross-section of fiber/epoxy fractured specimen, evidencing good wetting by the polymer [9] (b) shows fragmentation tests on CNT fibers in epoxy, for fibers infiltrated with PVA (a) and PI (b) [78]. With kind permission from Elsevier (2009, 2011).

Figure 2. C Is XPS of interfacial surfaces of Adhesive E showing (a) C Is XPS spectrum of untested Adhesive E surface having peaks at 285.0 eV, 285.7 eV, 286.7 eV, and 287.9 eV (b) C Is XPS spectrum of interfacial Adhesive E polymer surface after corrosion showing peaks identical to (a) ...

Plasma films are usually highly cross-linked, resistant to higher temperatures, resistant to abrasion and chemical attack, and are highly adherent to the surface. Adhesion to the surface is generally high both because the growing polymer complex can fit the surface contour and thus lock-itself in (physical adhesion), and because in many instances, the species are active enough to chemically react with the surface molecules to chemically bond to the surface. The surface can be prepared so that the chemical reaction is enhanced. 

Dewez JL, Lhoest JB, Detrait E et al. (1998) Adhesion of mammalian cells to polymer surfaces from physical chemistry of surfaces to selective adhesion on defined patterns. Biomaterials 19 1441-1445... 

Pressure-Sensitive Adhesives—These are really viscous polymers which melt at room temperature, so the polymers must be used at temperatures above their Tg values to permit rapid flow. The adhesives flow because of the application of pressure. When the pressure is removed, the viscosity of the polymer is high enough to retain its adhesion to the surface. Many adhesive tapes are of this type the back is smooth and coated with a nonpolar coating which does not bond with the sticky surface. 

Highly reactive (unstable) and nonselective species tend to react with any surface on which the species strike and form a polymer deposition with a high level of bonding or adhesion to the surface. Because of this aspect, plasma polymerization tends to form a thin film with a good adhesion with various kinds of substrate materials. Because of nonselective reactivity, the reactive species of plasma polymerization have poor penetration into small cavities such as those of porous structures. Reactive species tend to react with wall material at the entrance of a cavity rather than penetrating into the cavity (which requires that the species not react with the wall at the entrance). 

The network polymers formed after hardening exhibit high strength and good electrical insulation properties, adhesion to polar surfaces and prolonged heat resistance at 150—180 °C. In order to improve fire resistance of OFM, residues of chlorinated dibasic acids and (or) diols with (or without) antimony oxide or phosphorous-containing comonomers are added. 

Lubricants Reduce polymer adhesion to metal surfaces acids Derivatives of fatty acids (esters, amides, metal... 

Interest in the adhesion of dosage forms to epithelial surfaces has heen aroused hy the possihility of deliberate contact between oral dosage forms and the gut wall to retard the rate of transit down the gastrointestinal tract, but also by the possibility of dosage forms accidentally adhering to the oesophagus or other epithelial surfaces. Adhesive preparations have been formulated for diverse tasks such as the topical treatment of stomatitis and the administration of insulin. The adhesive nature of transdermal patches is important, as is the adhesion of film coats to tablet surfaces. Adhesion of erythrocytes and bacterial cells to polymer surfaces is also of importance in the understanding, respectively, of blood compatibility of polymers and bacterial infection mediated by catheters. 

Table 1. Carbon black surface characteristics mid adhesion to polymer ...

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