Accudynetest logo

Products available online direct from the manufacturer

ACCU DYNE TEST ™ Bibliography

Provided as an information service by Diversified Enterprises.

3042 results returned
showing result page 51 of 77, ordered by

1633. Sapieha, S., J. Cerny, J.E. Klemberg-Sapieha, and L. Martinu, “Corona versus low pressure plasma treatment: Effect on surface properties and adhesion of polymers,” J. Adhesion, 42, 91, (1993).

Low density polyethylene (PE) and polyethylene terephthalate (PET) films were treated in air plasma of a low pressure (500 mTorr) large area microwave (2.45 GHz) discharge, or in a corona discharge at atmospheric pressure. The modified surfaces were characterized by X-ray photoelectron spectroscopy (XPS) for their oxygen content [O] and surface chemical structure, which were related to the corresponding peel strength of PE/PE and PE/PET laminates. Although the oxygen concentration at the surface increased monotonically with the degree of treatment, the peel force reached a maximum and then sharply decreased. Regardless of the treatment type, the maximum peel force occurred for [O] values between 10-15 at.%. The highest peel force has been found to occur when the concentration of CSingle BondO (hydroxyl, ether, epoxy,…) groups is highest and that of OSingle BondCSingle BondO (carboxyl) groups is lowest, which corresponds to the situation when the effect of a weak boundary layer, due to low molecular weight materials, is minimal (low OSingle BondCSingle BondO concentration).

1602. Behnisch, J., A. Hollander, and H. Zimmerman, “Factors influencing the hydrophobic recovery of oxygen-plasma-treated polyethylene,” Surface and Coatings Technology, 59, 356-358, (1993).

The hydrophobic recovery of oxygen-plasma-treated hydrophilic surfaces of polyethylene and polypropylene films was investigated by measuring the dependence of the contact angle with the water on the vacuum storage time. It could be shown that the rehydrophobation of the polyethylene surface may be retarded by the previous controlled surface cross-linking in a hydrogen plasma and/or by repeated plasma treatment. However, the loss in hydrophilicity cannot be suppressed for ever. After certain individual periods all treatments lead to the same final state. Nevertheless, in particular, controlled cross-linking seems to be a suitable way for improving the long-term stability of plasma-functionalized polymer surfaces for polymers not tending to chain scission during plasma treatment.

1589. Liston, E.M., and M.R. Wertheimer, “Plasma surface modification of polymers for improved adhesion: a critical review,” J. Adhesion Science and Technology, 7, 1091-1127, (1993).

Since the earliest systematic research during the 1960s, the field of materials surface modification by 'cold', low-pressure plasma treatment has undergone an enormous expansion. Much of this expansion has taken place in recent years, particularly in the surface modification of polymeric materials, for which there now exist numerous industrial applications (enhancement of paint adhesion, improved bonding in polymer matrix composites, etc.). In this paper, we provide a critical review of the development and trends in this field; reference is also made to other surface modification techniques, particularly to corona treatment, and comparisons are made wherever appropriate. We begin with a brief overview of adhesion theory, and of the physics and chemistry of 'cold' plasmas. Next, interaction mechanisms between a plasma and a polymer surface are examined; these include physical bombardment by energetic particles and by ultraviolet photons, and chemical reactions at or near the surface. The resulting four main effects, namely cleaning, ablation, crosslinking, and surface chemical modification, occur together in a complex synergy, which depends on many parameters controlled by the operator. In spite of this complexity, for there are still many unanswered questions, it is nevertheless possible to optimize the main set of parameters governing a given process, and then to reliably reproduce the process outcome. Three industrially important systems, for which many research results exist, are then separately examined, namely: (i) polymer-polymer bonding, (ii) polymer-matrix composites, and (iii) metal-polymer bonding. Finally, we present a brief overview of commercial plasma reactors for industrial (non-semiconductor) purposes, and of process considerations for efficient use of such equipment. We foresee that the use of plasma processes will continue to expand, because they have unique capabilities, are economically attractive, and are 'friendly' towards the environment.

1450. Kaczinski, M.B., and D.W. Dwight, “Enhancement of polymer film adhesion using acid-base interactions determined by contact angle measurements,” J. Adhesion Science and Technology, 7, 165-177, (1993) (also in Contact Angle, Wettability and Adhesion: Festschrift in Honor of Professor Robert J. Good, K.L. Mittal, ed., p. 739-751, VSP, Nov 1993).

Quantitative correlations among surface chemical composition, acid-base thermodynamics, adhesion strength, and locus-of-failure are demonstrated. Four types of functional Teflon surfaces were prepared: two acidic (containing hydroxyl and carboxyl groups), and two basic (containing acetyl and dinitrobenzoate groups). X-Ray photoelectron spectroscopy (XPS) and attenuated total reflection infrared (ATR-IR) spectroscopy were used to characterize the molecular structure of the surface region. Contact angle adsorption isotherms were determined using phenol as an acidic probe and tetrahydrofuran (THF) as a basic probe. The carboxylated surface had a higher molar ▵Hab with basic THF than the hydroxylated surface, and neither surface had any interaction with the acidic phenol probe. The acetylated surface behaved as a base, interacting with phenol but not with THF, while the dinitrobenzoyl surface had both acidic and basic character. Adhesion tests were carried out in the 180° peel mode using post-chlorinated poly(vinyl chloride) as a model acidic adhesive between pairs of each type of film. The two surfaces with basic character had significant peel strengths, while the two acidic surfaces had very low peel strengths. Scanning electron microscopy (SEM) of the basic failure surfaces showed significant plastic deformation of the Teflon polymer, while the acidic failure surfaces showed no deformation. XPS analysis of the failure surfaces confirmed interfacial failure for the acid-acid pairs, and bulk FEP failure for the acid-base pairs. These results demonstrate directly and quantitatively the enhancement of adhesive bond strength through acid-base interactions.

1448. Brewis, D.M., I. Mathieson, I. Sutherland, and R.A. Cayless, “Adhesion studies of fluoropolymers,” J. Adhesion, 41, 113-128, (1993).

A comparative study of the treatment of polytetrafluoroethylene (PTFE) and poly(vinyl fluoride) (PVF) with “Tetra-Etch” has been carried out. The treatment of PTFE resulted in extensive changes in surface chemistry and topography, whereas with PVF there was no significant change in topography and the chemical changes were much less marked. However, treatment of both polymers resulted in large increases in bond strength.

Multiple bonding experiments in which samples are repeatedly fractured and re-bonded were carried out with untreated PTFE and PVF. These resulted in moderate increases in bond strength with PTFE and large increases with PVF. The results indicate that weak boundary layer (WBL) removal is a key element in adhesion improvement by “Tetra-Etch” on PVF. With PTFE, WBL removal also improves adhesion, but the chemical and/or topographical changes introduced by the “Tetra-Etch” are required for optimum performance.

1412. Okazaki, S., and M. Kogoma, “Development of atmospheric pressure flow discharge plasma and its application on a surface with curvature,” J. Photopolymer Science and Technology, 6, 339-342, (1993).

1369. Sabreen, S., “Surface treatments for electronic components - solutions for adhesive bonding problems,” Presented at NEPCON West, 1993.

1304. Lin, F.Y.H., D. Li, and A.W. Neumann, “Effect of surface roughness on the dependence of contact angles on drop size,” J. Colloid and Interface Science, 159, 86-95, (1993).

Absence of drop size dependence of contact angles of sessile drop systems is sometimes observed in experiments. The contact angle data sometimes fluctuate periodically about a horizontal line. Moreover, in cases where a drop size dependence of contact angles exists, the contact angle data often scatter significantly. These fluctuations may be caused by surface roughness. In this paper, two idealized rough surface models are developed. The mean contact angle of a sessile drop in each rough solid surface model is calculated. The fluctuations of the drop size dependence of contact angles produced by these models resemble those obtained experimentally and the fluctuations may therefore be a consequence of the roughness on solid surfaces. It is also concluded that the apparent absence of drop size dependence of contact angles does not necessarily imply zero or extremely low line tension.

1286. Gerenser, L.S., “XPS studies of in-situ plasma-modified polymer surfaces,” J. Adhesion Science and Technology, 7, 1019-1040, (1993).

X-ray photoelectron spectroscopy (XPS) has been used to study the chemical effects of both inert (argon) and reactive (oxygen, nitrogen, and mixed gas) plasma treatments done in situ on a variety of polymer surfaces. Inert gas plasma treatments introduce no new detectable chemical species onto the polymer surface but can induce degradation and rearrangement of the polymer surface. However, plasma treatments with reactive gases create new chemical species which drastically alter the chemical reactivity of the polymer surface. These studies have also shown that the surface population of chemical species formed after plasma treatment is dependent on both the chemical structure of the polymer and the plasma gas. The effects of direct and radiative energy-transfer processes in a plasma have also been studied. Polymers containing certain functional groups were found to be more susceptible to damage via radiative energy transfer. Ageing studies of plasma-modified polymer surfaces exposed to the atmosphere have shown that the ageing process consists of two distinct phases. The initial phase, which occurs rapidly, involves adsorption of atmospheric contaminants and, in some cases, specific chemical reactions. The second phase, which occurs slowly, is due to surface reorganization.

1079. Novak, I., and V. Pollak, “Modification of adhesive properties of isotactic polypropylene,” Intl. Polymer Science and Technology, 20, T/77-80, (1993).

911. no author cited, “Discussion of activated gas plasma process,” Advanced Plasma Systems, Inc., 1993.

873. Springer, J., and G. Schammler, “Adhesion between plastics and metals: basics,” in Metallizing of Plastics: A Handbook of Theory and Practice, Suchentrunk, R., ed., 3-29, ASM International, 1993.

833. Morra, M., E. Occhiello, and F. Garbassi, “Chemical reactions on plasma-treated polyethylene surfaces,” J. Adhesion Science and Technology, 7, 1051-1063, (1993) (also in Plasma Surface Modification of Polymers: Relevance to Adhesion, M. Strobel, C.S. Lyons, and K.L. Mittal, eds., p. 183-196, VSP, Oct 1994).

828. Foerch, R., G. Kill, and M.J. Walzak, “Plasma surface modification of polyethylene: short-term vs. long-term plasma treatment,” J. Adhesion Science and Technology, 7, 1077-1089, (1993) (also in Plasma Surface Modification of Polymers: Relevance to Adhesion, M. Strobel, C.S. Lyons, and K.L. Mittal, eds., p. 99-112, VSP, Oct 1994).

826. Gerenser, L.J., “XPS studies of in situ plasma-modified polymer surfaces,” J. Adhesion Science and Technology, 7, 1019-1040, (1993) (also in Plasma Surface Modification of Polymers: Relevance to Adhesion, M. Strobel, C.S. Lyons, and K.L. Mittal, eds., p. 43-64, VSP, Oct 1994).

825. Liston, E.M., L. Martinu, and M.R. Wertheimer, “Plasma surface modification of polymers for improved adhesion: a critical review,” J. Adhesion Science and Technology, 7, 1091-1127, (1993) (also in Plasma Surface Modification of Polymers: Relevance to Adhesion. M. Strobel, C.S. Lyons, and K.L. Mittal, eds., p. 3-42, VSP, Oct 1994).

686. Silvain, J.F., and J.J. Ehrhardt, “An overview on metal/PET adhesion,” Thin Solid Films, 236, 230-235, (1993).

Transmission electron microscopy and X-ray photoelectron spectroscopy (XPS) were used to characterise thin metal films (Mg, Al, Cu, Ag) thermally evaporated onto polyethylene terephthalate (PET) and to study the formation of the Al/PET interface. The adhesion was measured with a 180° peel test technique. XPS spectra show that the Al atoms react preferentially with the carboxylic group of the PET and that the Al/PET interface exhibits a pseudo layer-by-layer growth mechanism. Two factors strongly favour the increase of metal/PET adhesion: (1) a PET temperature higher than 100°C during metal deposition (Al, Cu and Ag) and (2) a partial pressure of oxygen higher than 10−5 mbar for the Al evaporation. Furthermore, atomic metal diffusion tends to increase the adhesion while cluster segregation within the PET skin decreases the metal/PET adhesion.

597. Whitehouse, S.L., “Advances in adhesion of thermoplastic elastomers to other substrates,” in ANTEC 93 (Volume 1), 928-932, Society of Plastics Engineers, 1993.

469. Gutowski, W.S., “Novel surface treatment process for enhanced adhesion of ultra-high modulus PE fibres to epoxy resins,” Composite Interfaces, 1, 141-151, (1993).

Ultra-high modulus polyethylene (UHMPE) fibres have been treated using a novel 'non-plasma' treatment allowing the incorporation of various chemical functional groups onto the polymer surface. The process comprises two steps: corona discharge treatment, followed by silanization of the polymer surface by a solution of an organo-functional silane. Corona discharge treatment incorporates oxygen-containing functionalities, e.g. reactive hydroxyl groups, onto the polymer surface. The presence of reactive -OH groups provides the possibility of covalent linkage of any organo-functional silane to the corona discharge-treated polymer in the form of a fibre, film, sheet, or powder. The effectiveness of the process was assessed by examining the interlaminar fracture energy and flexural modulus and by SEM analysis of the fracture surfaces of composites fabricated from the untreated, corona discharge-treated, ammonia plasma-treated, and the amine-grafted (using the novel process) UHMPE fabric. A significant improvement in interfacial adhesion was confirmed by increases in the interlaminar fracture energies and flexural moduli. The effectiveness of the process investigated is similar to the ammonia plasma treatment. SEM analysis of the fracture surfaces indicated a change in the fracture mode from purely adhesive for unmodified fibres, through to mixed failure mode for corona-treated material, to highly cohesive-in-fibre surface for amine-grafted UHMPE fibres. XPS analysis confirmed the incorporation of the amine groups onto the surface of polyethylene treated using the novel method.

418. Bataille, P., N. Belgacem, and S. Sapieha, “Properties of cellulose-polypropylene compounds subjected to corona treatment,” in ANTEC '93, 325-329, Society of Plastics Engineers, 1993.

308. Sakata, I., M. Morita, N. Tsurata, and K. Morita, “Activation of wood surface by corona treatment to improve adhesive bonding,” J. Applied Polymer Science, 49, 1251-1258, (1993).

Oxidative activation of resinous wood surfaces by a corona treatment to improve adhesive bonding was studied. It was found that the wettability of the veneers, including hardwoods, softwoods, and tropical woods increased with an increase in the degree of treatment, and the gluability increased rapidly after the initial mild treatment. To elucidate the nature of any chemical change occurring on the wood surface, the dyeing examination of the wood and its components with Schiff's reagent was made, and the results showed a higher dyeing ability for corona-treated samples compared to untreated ones, indicating that aldehyde groups increased by the corona treatment. The treatment affected the alcohol-benzene extractives, and oxidized them to produce aldehyde groups. Especially, the neutral fraction in the extractives was significantly affected. On the other hand, negligible chemical effects of the treatment on the surface modification of the wood's main components were seen. Both the untreated and corona-treated samples adsorbed basic dye to the same extent of coloration. Thus, no measurable carboxyl groups increased on the surface of the samples. It seems that an increase in the wettability of corona-treated wood veneers resulted mainly from the oxidation of the high hydrophobic surface layer of neutral fraction substances in the extractives, and from the reduction in their hydrophobicity. © 1993 John Wiley & Sons, Inc.

283. Papirer, E., D.Y. Wu, and J. Schultz, “Adhesion of flame-treated polyolefins to styrene butadiene rubber,” J. Adhesion Science and Technology, 7, 343-362, (1993).

Samples of polyethylene and polypropylene have been submitted to repeated short duration (75 ms) flame treatments, at optimum flaming conditions. Surface energies of untreated and flamed specimens were determined by liquid contact angle measurements. It appears that the surface energy of polyethylene increases much more than that of polypropylene after flame treatment. The flamed polymer surfaces were further examined by electron spectroscopy, Fourier Transform IR spectroscopy and secondary ions mass spectrometry. The adhesion properties of modified polymer surfaces were studied by testing in peel the bonded Styrene Butadiene Rubber/polyolefins assemblies. Scanning electron microscopy (SEM) and water contact angle measurements have been used to observe the locus of failure. Good correlations were obtained between surface energy and adhesion strength, the increase in adhesion strength being particularly important for flamed PE/SBR assemblies. In addition, the peeling in a liquid medium allowed the determination of the respective contribution to adhesion of chemical and physical interactions. It is shown that a major part of the adhesion strength increase is of chemical origin, particularly for the bonded flamed PE/SBR assemblies.

272. Onyiriuka, E.C., “The effects of high-energy radiation on the surface chemistry of polystyrene: a mechanistic study,” J. Applied Polymer Science, 47, 2187-2194, (1993).

Irradiation of polystyrene by 15 Mrad gamma or exposure to a 254 nm ultraviolet (UV) light source leads to surface oxidation of the polymer to depths greater than 10 nm as opposed to ∼ 3 nm depth offered by either plasma or corona-discharge treatment. Oxidation increases linearly with UV irradiation time. More carboxyl (ODouble BondCSingle BondO) acid functionality, which increases with depth, was detected for UV-treated polymer. With 3 Mrad gamma irradiation, only hydroxyl (CSingle BondC) groups were detected by XPS as the surface-oxidized species. ADXPS, GPC, and static SIMS data suggest that chain scission is the dominant degradation mechanism for polystyrene exposed to high gamma and UV radiation, respectively. © 1993 John Wiley & Sons, Inc.

246. Morra, M., E. Occhiello, and F. Garbassi, “Chemical reactions on plasma-treated polyethylene surfaces,” J. Adhesion Science and Technology, 7, 1051-1063, (1993).

Oxygen plasma treatment as a surface functionalization technique is discussed. Oxygen-containing functionalities were introduced on the surface of high- (HDPE) and low-density polyethylene (LDPE) by glow discharge. The number of surface hydroxyl groups was increased by a post-discharge wet treatment in a reducing solution. The effects of the substrate nature, the discharge parameters, and the post-discharge wet treatment on the surface functional groups are discussed, and the effectiveness of functionalized surfaces on the yield of coupling reactions is shown.

237. Mercx, F.P.M., “Improved adhesive properties of high-modulus polyethylene structures, II. Corona grafting of acrylic acid,” Polymer, 34, 1981-1983, (1993).

High-modulus polyethylene (PE) tapes were grafted with acrylic acid using a two-step procedure. The tapes were first subjected to He/Ar corona discharge, immediately followed by exposure of the corona-treated tapes to acrylic-acid-saturated He gas. Evidence for the grafting was provided by X-ray photoelectron spectroscopy, which showed the surface of the treated tapes to consist of 64% acrylic acid and 36% PE. The grafting of acrylic acid is confined to the outermost surface layers, as indicated by reflection infra-red spectroscopy. Pull-out tests showed that the corona grafting of acrylic acid improves adhesion to epoxy resins by a factor of eight. Moreover, the increased adhesion is not achieved at the expense of a decrease in mechanical properties of the high-modulus PE tapes.

218. Lee, L.-H., “Roles of molecular interactions in adhesion, adsorption, contact angle, and wettability,” J. Adhesion Science and Technology, 7, 583-634, (1993) (also in Contact Angle, Wettability and Adhesion: Festschrift in Honor of Professor Robert J. Good, K.L. Mittal, ed., p. 45-96, VSP, Nov 1993).

This study is aimed at understanding the controversy between the surface tension component (STC) theory and the equation of state (EQS) approach for interfacial tensions. We attempt to relate molecular interactions to various components of surface tension. Molecular interactions consist of electrostatic (ES), charge transfer (CT), polarization (PL), exchange-repulsion (EX), dispersion (DIS), and coupling (MIX) components. These interactions can be the basis for the STC theory involving Lifshitz-van der Waals (LW) and the short range acid-base (AB) or donor-acceptor interaction. Each of these components is shown to contain two major parameters. New equations for the interaction energy and surface tension for polar molecules are proposed to include the ES and EX parameters, which happen in some cases to balance each other or nearly cancel out without being detected. The roles of molecular interactions on adhesion, adsorption, contact angle, and wettability are illustrated through the spreading coefficient S, the Hamaker coefficient A, and Derjaguin's disjoining pressure . We have found that the STC theory is applicable to the systems involving either physisorption or chemisorption, whlie the EQS applies to those involving ony physisorption.

206. Kuznetsov, A.Y., V.A. Bagryansky, and A.K. Petrov, “Adhesion properties of glow-discharge plasma treated polyethylene surfaces,” J. Applied Polymer Science, 47, 1175-1184, (1993).

A geometric method proposed by Kaelble and Moacanin for analyzing energetic characteristics of solid surfaces is discussed. It is shown that a number of characteristics can be presented in a visual geometric form. The method is applied to the analysis of adhesion in a three-component system. Results of the analysis, concerned with the problem of creation of biocompatible materials, support the Andrade hypothesis that materials with zero interfacial tension of their water–solid interface show maximum biocompatibility. Data are obtained on wetting of polyethylene by different liquids before and after glow discharge plasma treatment. The analysis of these data in terms of geometric method shows the plasma treatment increased the polar component of the polymer surface energy to change the surface adhesiveness toward probable enhancement of polymer biocompatibility. That is consistent with available data on glow-discharge-treatment enhancement of biocompatibility for a number of polymers. © 1993 John Wiley & Sons, Inc.

195. Kinbara, A., A. Kikuchi, S. Baba, and T. Abe, “Effect of plasma treatment of PTFE substrates on the adhesion characteristics of vacuum-deposited Au films,” J. Adhesion Science and Technology, 7, 457-466, (1993).

PTFE foils were plasma-treated in order to enhance their adhesion to thin films. The effect of plasma treatment using argon and oxygen discharge gases on the surface energy of PTFE foils was examined by measuring the contact angles of water droplets placed on the foil surface. Exposure to the plasma for only about 10-20 s was very effective in enhancing the surface energy. By depositing gold films onto the PTFE substrates, it was found that this enhancement in surface energy was directly related to an increase in the film adhesion. It was also found that Ar plasma treatment of a few tens of seconds followed by O2 plasma treatment for 10 s was even more effective for adhesion enhancement.

161. Hoebergen, A., Y. Uyama, T. Okada, and Y. Idada, “Graft polymerization of fluorinated monomer onto corona-treated PVA cellulose films,” J. Applied Polymer Science, 48, 1825-1829, (1993).

Surface graft polymerization of a hydrophobic monomer, 2,2,3,3,3-pentafluoropropyl methacrylate (5FMA), onto hydrophilic poly(vinyl alcohol) (PVA) and cellulose films was studied after corona discharge of the films. It was found that grafting strongly depended on the reaction medium; especially, addition of alcohol to the monomer greatly accelerated graft polymerization. For instance, when an ethanol/ water /5FMA mixture (65/25/10, by volume) was used as the polymerization medium. the PVA and cellulose films corona-discharged for a few minutes exhibited a high contact angle up to 100° after 30 min polymerization, the graft density being approximately 170 μg/cm2 for cellulose and 80 μg/cm2 for PVA. © 1993 John Wiley & Sons, Inc.

102. Foerch, R., G. Kill, and M.J. Walzak, “Plasma surface modification of polyethylene: short-term vs. long-term plasma treatment,” J. Adhesion Science and Technology, 7, 1077-1089, (1993).

A remote plasma reactor, with air as the plasma gas, has been used for in-line surface modification of linear low-density polyethylene tape (LLDPE) passing 10 cm below the main plasma zone. Line speeds of up to 0.70 m/s were tested, allowing the study of 0.014 s exposure times to the plasma. Oxygen to carbon (O/C) ratios averaging 0.11 were observed on a reproducible basis. The reactor was also used for static plasma treatment under similar experiment onditions. This allowed a comparative study of short-term (milliseconds) vs. long-term (several seconds) plasma treatment. High-resolution X-ray photoelectron spectroscopy (XPS) analysis of the treated polymer surface suggested the formation of hydroxyl (CSingle BondOH), carbonyl (CDouble BondO) and carboxyl (OSingle BondCDouble BondO) groups, even after short plasma treatment. The intensities of these components were seen to increase in approximately equal quantities with increasing O/C ratio. Water washing of polyethylene surfaces with high O/C ratios showed a loss of oxygen, apparent as a decrease in OSingle BondCDouble BondO groups in the C 1s spectra. A smaller loss in oxygen was observed when washing samples that had been plasma-treated for milliseconds. A surface ageing study revealed that polyethylene surfaces that had been plasma-treated for short time periods showed only a negligible loss of oxygen on prolonged exposure to air. Surfaces treated for longer time periods showed a loss of up to 50% of the total oxygen on the surface within a few days of treatment. Static secondary ion mass spectrometry has provided some supporting evidence for surface damage of the treated films.

34. Bonnerup, C., and P. Gatenholm, “The effect of surface energetics and molecular interdiffusion on adhesion in multicomponent polymer systems,” J. Adhesion Science and Technology, 7, 247-262, (1993) (also in Contact Angle, Wettability and Adhesion: Festschrift in Honor of Professor Robert J. Good, K.L. Mittal, ed., p. 753-768, VSP, Nov 1993).

The interfacial region of coated plastics is an example of a multicomponent polymer system. Practical adhesion, as determined by the peel test, has been found to be strongly dependent on the composition of the system and the degree of interaction between its components. Several interactions are possible during the coating process of polypropylene (PP)/ethylenepropylene-diene-monomer (EPDM) blends with chlorinated polyolefin (primer) and polyurethane (PUR) paint. Wettability, a necessary but not sufficient condition alone for molecular interdiffusion, was found to be good in all cases. The lack of interfacial adhesion between PP and PUR and between EPDM and PUR was explained by high interfacial tensions calculated from surface energetics, which, in turn, were determined by contact angle and inverse gas chromatography (IGC) measurements. The improvement of interfacial adhesion between PUR and PP by chlorinated polyolefin was explained by acid-base interactions detected by IGC. The creation of surface topography by extraction of low molecular weight fractions during the coating process does not influence the adhesion. Molecular interdiffusion was shown to be facilitated by solvents.

2061. Goldblatt, R.D., L.M. Ferreiro, S.L. Nunes, et al, “Characterization of water vapor plasma-modified polyimide,” J. Applied Polymer Science, 46, 2189-2202, (Dec 1992).

To enhance polyimide-to-polyimide adhesion, we have investigated the effect of surface modification in water vapor plasma. The use of a water vapor plasma to treat a fully cured polyimide (PMDA–ODA) surface before subsequent layers of polyimide are applied results in dramatically enhanced interfacial adhesion. The polyimide-to-polyimide interfacial adhesion strength attained following water vapor plasma treatment exceeds the cohesive strength of the applied polyimide layer. The effect of surface modification in water vapor plasma on metal-to-polyimide adhesion has also been investigated. The use of a water vapor plasma to treat a fully cured polyimide (PMDA–ODA) surface prior to metallization results in increased metal-to-polymer interfacial adhesion. A study of both electroless and vacuum-deposited metal was conducted. The use of contact-angle measurements, peel tests, Fourier transform infrared spectroscopy, optical emission spectroscopy, nuclear forward scattering, and X-ray photoelectron spectroscopy has led us to a preliminary understanding of the resulting surface modification and the subsequent effect of adhesion promotion. © 1992 John Wiley & Sons, Inc.

940. Bezigian, T., “Overview of primer technology: A variety of priming techniques exists to aid the extrusion coater in meeting today's increasingly complex requirements,” Converting, 10, 60-65, (Dec 1992).

2083. Lee, J.H., and H.B. Lee, “Surface modification of polystyrene dishes for enhanced cell culture,” Polymer (Korea), 16, 680-686, (Nov 1992).

2387. Thurm, S., U. Reiners, I. Schinkel, and M. Kowitz, “Process for the treatment of polyolefin films,” U.S. Patent 5152879, Oct 1992.

1348. Schut, J.H., “Plasma treatment: The better bond,” Plastics Technology, 38, 64-69, (Oct 1992).

348. Spelt, J.K., D. Li, and A.W. Neumann, “The equation of state approach to interfacial tensions,” in Modern Approaches to Wettability: Theory and Applications, Schrader, M.E., and G.I. Loeb, eds., 101-142, Plenum Press, Oct 1992.

Striking a balance between applied and theoretical research, this work details many of the uses of wettability and interprets experimental data from a variety of viewpoints, including the ‘separation of forces’ and the ‘equation of state approaches.’

326. Schultz, J., and M. Nardin, “Determination of the surface energy of solids by the two-liquid-phase method,” in Modern Approaches to Wettability: Theory and Applications, Schrader, M.E., and G.I. Loeb, eds., 73-100, Plenum Press, Oct 1992.

The surface free energy of solids is a characteristic parameter that determines most of the surface properties such as adsorption, wetting, adhesion, etc. The surface energetics of solids may be characterized by measurement of contact angles of different liquids. Nevertheless, the calculation of surface free energy from contact angle measurements has been the subject of much controversy. Indeed, this characteristic of a solid cannot be measured directly because of elastic and viscous restraints of the bulk phase, which necessitate indirect methods.

325. Schrader, M.E., and G.I. Loeb, eds., Modern Approaches to Wettability: Theory and Applications, Plenum Press, Oct 1992.

315. Schoff, C.K., “Wettability phenomena of coatings,” in Modern Approaches to Wettability: Theory and Applications, Schrader, M.E., and G.I. Loeb, eds., 375-395, Plenum Press, Oct 1992.


<-- Previous | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | Next-->