远程等离子体处理对聚四氟乙烯表面的功能化改性

采用远程氩等离子体对聚四氟乙烯(PTFE)膜进行了表面改性研究,通过接触角测定仪、扫描电子显微镜(SEM)和X射线光电子能谱仪(XPS)等手段,分析研究了改性后材料表面结构、性能的变化。结果表明:PTFE表面经远程氩等离子体处理后,表面微观形态和表面化学成分均发生了变化,且处理效果优于常规氩等离子体。远程氩等离子体可以在一定程度上抑制电子、离子的刻蚀作用,强化自由基反应,使材料表面获得更好的改性效果。经远程氩等离子体短时间(100s)处理后,PTFE表面的F/C比例从1.97降至1.44,O/C比例从0.015增至0.086;表面的水接触角从108°减小到53°;表面自由能从22.4×10-5N·cm-1增加至52.3×10-5N·cm-1。     

Surface modification of poly(aryl ether ether ketone) film by remote oxygen plasma

Surface modification of poly(aryl ether ether ketone) (PEEK) film surfaces by oxygen plasma treatment was investigated. Two procedures, the direct plasma treatment and the remote oxygen plasma treatment, were used as oxygen plasma treatments, and the efficiency of the hydrophilic modification was discussed. The direct and remote oxygen plasma treatments lead to degradation of the PEEK film as well as hydrophilic surface modification. The degradation disturbs the surface modification. The remote oxygen plasma treatment rather than the direct oxygen plasma is suitable for the hydrophilic surface modification of the PEEK film. The remote oxygen plasma treatment at 10 W for 60 s forms predominantly C—O groups rather than C=O groups as an oxygen-containing group on the PEEK surface and gives a highly hydrophilic surface with a contact angle of 44 degrees. © 1998 John Wiley & Sons, Inc. J Appl Polm Sci 68:271–279, 1998     

Surface modification of poly(ethylene terephthalate) by electrical discharge treatment

Poly(ethylene terephthalate) (PET) film has been discharge-treated under controlled conditions and the resulting surface modifications analysed via X.p.s. (ESCA), contact angle and surface energy measurements. Changes in surface properties have been followed as a function of ageing time. These measurements have been correlated with the adhesive properties of the treated surfaces using autoadhesion (treated-treated seals) as the probe. Discharge treatment introduces phenolic -OH and carboxylic acid -COOH groups into the surface resulting in increased wetting and much enhanced autoadhesion via hydrogen bonding of phenol groups to carbonyl groups. Much chain scission also occurs; the low molecular weight material is easily removed by washing and migrates into the film on ageing. The new functionalities in relatively immobile chains slowly reorientate and internally H-bond. The former process is largely responsible for the wettability change on aging, the latter for the loss of adhesive properties.     

Surface modification of poly(ethylene terephthalate) fiber by excimer light

Changes in the surface topography and chemical structure on the surfaces of poly(ethylene terephthalate) (PET) fibers and films caused by the irradiation using an excimer laser beam and excimer lamp light were monitored. The SEM (scanning electron microscopy) observation suggests that a wavy shape was produced by irradiation with the excimer laser beam, while such a wavy shape was not observed when the excimer lamp light was used. The XPS (X-ray photoelectron spectroscopy) analysis of the fiber surface suggests that the O/C intensity ratio was reduced by irradiation using the laser beam, whereas this ratio gradually increased with irradiation with the lamp light. This difference is attributed to the difference in the number of photons in the laser beam, which was much higher than that in the lamp light, although the laser beam and lamp light had the same wavelength and energy. As for wettability to water, the contact angle was smallest for PET irradiated by the excimer lamp light. For adhesion studies, the PET fabric was first coated with an epoxy acrylate solution, irradiated with excimer light, dipped into RFL (resorcinol-formaldehyde-latex) adhesive, and the peel strength to rubber sheet was examined. When the irradiation by the excimer laser beam was compared with that with the excimer lamp light, the laser irradiation showed a good adhesion property even for rubber vulcanization carried out for a long time at high temperature.     

Surface modification of poly(tetrafluoroethylene) and poly(ethylene terephthalate) films via environmental crazing

This work addresses the phenomenon of the development of a patterned surface relief on polymer films via different modes of environmental crazing. Commercial films of semicrystalline poly(tetrafluoroethylene) (PTFE) and amorphous glassy poly(ethylene terephthalate) (PET) were subjected to tensile drawing in the presence of physically active liquid environments (carbon tetrachloride or aliphatic alcohols). The structure parameters and wettability of the modified films were studied by AFM, SEM, profilometer measurements and contact angle measurements. Environmental intercrystallite crazing of PTFE is accompanied by the development of an unstable structure with a high free surface, which experiences marked strain recovery upon unloading. As a result of the relief formation, PTFE hydrophobicity is enhanced (the water contact angle increases by 25°). Classical environmental crazing of PET films is accompanied by the formation of an anisotropic surface relief which is an assembly of crazes oriented perpendicular to the direction of tensile drawing, thus leading to the phenomenon of anisotropic wetting. The proposed approach for structural surface modification makes it possible to use the advantages of surface instability and spontaneous self‐organization of the polymer towards the development of a unique surface microrelief. © 2020 Society of Chemical Industry     

Surface modification of polypropylene. I. Surface enrichment of poly(ethylene glycol) on polypropylene/poly(ethylene glycol) blends

The enrichment of poly(ethylene glycol) (PEG) on the surface of poly(ethylene glycol)/polypropylene (PEG/PP) blends was investigated by using attenuated total reflection infrared spectroscopy (ATR‐FTIR), contact angle measurement (CDA), and scanning electron microscopy (SEM). The preferred aggregation of the PEG component on the film surface of PP/PEG blends was affected mainly by the content, the molecular weight, and the segregated domains of PEG. Lower content and dies with higher surface energy favored the surface enrichment of PEG. The PEG with higher molecular weights was distributed in PP with larger phase domains, which resulted in a lower tendency toward preferred aggregation and surface enrichment. J. VINYL ADDIT. TECHNOL, 2008. © 2008 Society of Plastics Engineers     

Surface modification of poly(tetrafluoroethylene) with pulsed hydrogen plasma

Surface modification of polymers by pulsed plasma has been investigated to minimize degradation reactions occurring at the same time as the surface modification reactions. The hydrogen radical, ion, and electron concentrations in the hydrogen plasma were simulated as a function of the elapsed time after turning off the discharge. The contact angle measurement showed that hydrogen plasma treatment, regardless of pulsed or continuous plasma, led to degradation reactions as well as defluorination and oxidation on PTFE surfaces. The degradation reactions of PTFE chains initiated by the pulsed hydrogen plasma were not as vigorous as those by the continuous hydrogen plasma. A combination of the on‐time/off‐time of 30/270μs in the pulsed hydrogen plasma was efficacious in modifying PTFE surfaces. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 340–348, 2002     

Surface modification of silicone rubber with poly(ethylene glycol) hydrogel coatings

Hydrogel coatings of monoacrylated poly(ethylene glycol) (PEG) methyl ethers of different molecular weights were attached to silicon rubber surfaces and crosslinked with hexanediol diacrylate or ethoxylated trimethylolpropane diacrylate by UV polymerization. The wetting, evaluated with the water contact angles, correlated with the surface oxyethylene chain density, which was evaluated with the ESCA >C? O? /? CH₂? ratio obtained from the C(1s) peak. As measured by the ESCA N(1s) peak, bovine serum albumin formed very thin protein adsorbates on the PEG‐coated surfaces. A strong correlation was found between low protein adsorption and a high >C? O? /? CH₂? ratio of the PEG‐coated substrate. The PEG‐coated silicon rubber also demonstrated very low cell and platelet adhesion. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1486–1492, 2004     

Surface modification of poly(ethylene terephthalate) film by coating with poly(ethylene glycol)‐grafted polystyrene

The poly(ethylene glycol) (PEG)‐grafted styrene (St) copolymer, which was formed as a nanosphere, was used as an agent to modify the surface of poly(ethylene terephthalate) (PET) film. The graft copolymer was dissolved into chloroform and coated onto the PET film by dip–coating method. The coated amount depends on the content ratios of PEG and St, the solution concentration, and the coating cycles. The graft copolymers having a low molecular weight of PEG‐ or St‐rich content was fairly stable on washing in sodium dodecyl sulfate (SDS) aqueous solution. It was confirmed that the PET surface easily altered its surface property by the coating of the graft copolymers. The contact angles of the films coated with the graft copolymers were very high (ca. 105–120°). The coated film has good antistatic electric property, which agreed with PEG content. The best condition of coating is a one‐cycle coating of 1% (w/v) graft copolymer solution. The coated surface had water‐repellency and antistatic electric property at the same time. The graft copolymer consisted of a PEG macromonomer; St was successfully coated onto PET surfaces, and the desirable properties of both of PEG macromonomer and PSt were exhibited as a novel function of the coated PE film. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1524–1530, 1999     

Impact modification of poly(ethylene terephthalate)

The tensile and impact resistance of impact‐modified poly(ethylene terephthalate) (PET) is investigated. The impact modifiers are polyolefin‐based elastomers or elastomer blends containing glycidyl methacrylate moieties to improve the adhesion with the polyester. The tensile properties are measured on injection molded specimens at room temperature while the Izod impact strength is measured from ?40 to 20°C. The blend morphology is observed by scanning electron microscopy and the dispersed phase average diameter is determined by image analysis. The relation between the impact resistance and the phase morphology is discussed, and the critical ligament size for PET is determined. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2919–2932, 2003     

Surface modification of poly(ethylene terephthalate) fibers via controlled radical graft polymerization

Functional chemical modifications on poly(ethylene terephthalate) (PET) fibers via radical graft polymerization could be controlled by managing mutual interactions and affinities between different components in the grafting reaction system. Hansen solubility parameters was used as a tool to quantify affinities of related agents and the polymer, and provided reliable results. The latest results proved the practicality of using Hansen solubility parameters in controlling radical graft polymerizations on surface modifications of PET fibers. Four different monomers with different hydrophilic properties in different solvent and initiator systems were examined, and results confirmed that interactions of initiator‐PET, initiator‐solvent, monomer‐PET, monomer‐solvent, and monomer‐initiator play important roles in determining the grafting reaction efficiency. Results revealed that for the selected grafting systems studied, hydrophilic monomers presented overall favoring affinities toward PET leading to higher grafting yields compared to hydrophobic monomers. The results have instructive impact to commercial applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45990.     

Photochemical surface modification of poly(ethylene terephthalate)

To elucidate the role of chemical interactions in the promotion of metal–polymer adhesion, a poly(ethylene terephalate)/copper system was studied. Surface photografting of unsaturated monomers containing different chemical functional groups onto a three-mil poly(ethylene terephthalate) film provided a means of examining a variety of copper-polymer interfaces. Initial graft verification was accomplished via contact angle measurements. Adhesion strengths to vacuum-deposited copper were determined using 90° peel tests. Graft analysis, as well as investigation of the interfacial interaction between copper and the grafted moieties, was accomplished using X-ray photoelectron spectroscopy.     

Surface modification of polyurethane by plasma-induced graft polymerization of poly(ethylene glycol) methacrylate

A new approach, plasma-induced graft polymerization of poly(ethylene glycol) methacrylate (PEGMA), was used to introduce PEG graft chains with hydroxyl end groups onto a polyurethane (Tecoflex) surface. After argon plasma treatment and subsequent exposure to air, graft polymerization onto Tecoflex films was allowed to proceed in deaerated aqueous solutions of PEGMA at 60°C. The virgin, plasma-treated, and grafted films were characterized comparatively by means of attenuated total reflection infrared spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, measurement of contact angle, and protein adsorption. The Tecoflex film undergoes etching during argon plasma treatment, surface oxidation when exposed to air after plasma treatment, and surface restructuring in response to environment upon storage in air. The plasma-induced graft polymerization of PEGMA proved to be successful in introducing PEG graft chains with reactive hydroxyl end groups onto the surface. Grafted films with different surface grafting density of PEG were prepared. Grafted films with higher PEG content exhibit higher hydrophilicity, smoother topography, and lower fibrinogen adsorption. The hydroxyl end groups built onto the surface offer further possibilities of improving its biocompatibility by immobilizing bioactive molecules. © 1996 John Wiley & Sons, Inc.     

Comparative studies on surface modification of poly(ethylene terephthalate) by remote and direct argon plasmas

Surface modification of poly(ethylene terephthalate) (PET) film by an argon (Ar) plasma was investigated as a function of the distance from the Ar plasma zone. Changes in distance between the PET film and the Ar plasma zone had a strong influence on the surface modification of the film. The direct Ar plasma treatment (distance between the PET film and Ar plasma zone = 0 cm) was effective in hydrophilic surface modification, but heavy etching reactions occurred during the modification. On the other hand, the remote Ar plasma treatment (distance between the PET film and Ar plasma zone = 80 cm) modified the PET film surfaces to be hydrophilic without heavy etching reactions, although the hydrophilicity of the PET was lower than that by the direct Ar plasma. The remote Ar plasma treatment was distinguished from the direct Ar plasma treatment from the viewpoint of degradation reactions. The remote Ar plasma treatment rather than the direct Ar plasma treatment was an adequate procedure for surface modification and caused less polymer degradation on the film surface. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 808–815, 2001     

Toughening of bismaleimide resin by modification with poly(ethylene phthalate) and poly(ethylene phthalate-co-ethylene isophthalate)

Aromatic polyesters were prepared and used to improve the brittleness of the bismaleimide resin composed of 4,4′-bismaleimidediphenyl methane and o,o′-diallyl bisphenol A. The aromatic polyesters contain poly(ethylene phthalate) (PEP) and poly(ethylene phthalate-co-ethylene isophthalate) (10 mol % isophthalate unit) (PEPI). PEP and PEPI were effective modifiers for improving the brittleness of the bismaleimide resin. The most suitable composition for the modification of the bismaleimide was inclusion of 20 wt % PEP (MW 18,200), which led to an 80% increase in the fracture toughness with retention of flexural properties and a slight decrease in the glass transition temperature, compared with the mechanical and thermal properties of the unmodified cured bismaleimide resin (Matrimid resin). Microstructures of the modified resins were examined by scanning electron microscopy and dynamic viscoelastic analysis. The thermal stability of the modified resin was slightly lower than that of the unmodified resin by thermogravimetric analysis. The toughening mechanism is discussed in terms of the morphological and dynamic viscoelastic behavior of the modified bismaleimide resin system. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 1349–1357, 1997     

Plasma-solution modification of poly(ethylene terephthalate) fibre material

Plasma-chemical modification of polyester thread ensures formation of active hydroxyl and carboxyl groups on its surface, necessary for fixation of functional preparations whose application on the surface of fibre material gives it new properties — water-repellent, antimicrobial, deodorizing, etc. A comparison of the efficacy of plasma-chemical and chemical methods of surface activation of polyester fibre material shows that in the first case, greater losses of strength are observed in the thread. However, in the case of plasma-chemical activation, an additional number of carbonyl/carboxyl groups is formed, which is an important advantage in selecting the method of activating polyester materials.     

Surface modification of corona treated poly(ethylene terephthalate) film: adsorption and wettability studies

Corona discharge treatment of poly(ethylene terephthalate) (PET) films produces chemical and physical modification of the surface leading to the formation of cavities and bumps. The roughness of the surface increases with the time of treatment and may be detected by scanning electron microscopy for the samples treated above 10 cycles, which corresponds to the duration of the exposure of the film under the electrodes. The degree of chemical modification, producing OH groups, is observed by adsorption of radioactive calcium ions and contact angle measurements. The results of these measurements are discussed and evidence presented shows that increase of the surface density of functional groups up to the value of 0.2 × 10¹⁴ sites/cm² leads to a rapid increase in wettability of PET films.     

Surface modification of carbon nanotubes with ethylene glycol plasma

Multi-walled carbon nanotubes (MWCNTs) were modified using plasma polymerization with ethylene glycol (EG) as monomer. Conditions of the EG plasma process in a specially designed reactor and the plasma-polymerized ethylene glycol (PPEG) coating were studied. The study involved varying the plasma powers of 10 and 20 W at a constant process time of 60 min, and EG flow rate of 0.15 cm³/min. Dispersion of the modified MWCNTs was evaluated in several solvents, showing hydrophilic behavior. Morphology of the PPEG coating and the functional groups (hydroxyl) on its surface were characterized by both transmission electron microscope and FTIR spectroscopy. Characterization by thermogravimetric analysis and FTIR suggested that the hydroxyl groups of the PPEG coating residing inside the nanotubes possessed higher thermal stability than the ones outside.     

Immobilization of poly(ethylene oxide) on poly(ethylene terephthalate) using a plasma polymerization process

Poly(ethylene oxide) (PEO) has been covalently immobilized on poly(ethylene terephthalate) (PET) films using a radio frequency glow discharge polymer deposition process, followed by chemical coupling. Amino or hydroxyl groups were introduced onto the surface of the PET by exposing the films to allylamine and allyl alcohol plasmas. These functional groups were activated with cyanuric chloride, and then they were reacted with PEO. ESCA and water contact angle studies were used to characterize the surfaces of these films during the different stages of the reaction. The films containing the higher molecular weight PEO exhibited an increase in the ? C? O? peak of the C_ls ESCA spectrum and an increase in oxygen content on the film surfaces. Increasing the molecular weight of the PEO attached to the PET also resulted in an increased wettability of the films.     

Surface analyses of corona-treated poly(ethylene terephthalate)

Poly(ethylene terephthalate) (PET) Mylar® samples were treated by corona discharge in order to improve their adhesive properties. The corona treatments were performed in different atmospheres including nitrogen, ammonia and air. X-ray photoelectron spectroscopy (XPS) was used to investigate the chemical modifications induced at the PET surface by these corona treatments. XPS results show that nitrogen incorporation takes place in the form of non-oxygenated nitrogen functionalities, like amine or cyano groups. These are present at the surface of all the corona-treated samples but in different concentrations depending on the gases used in the corona discharge. Furthermore, XPS analyses performed after heating of the treated samples show a higher thermal stability of the corona-induced surface modifications in the case of nitrogen and ammonia. Ion scattering spectroscopy (ISS) and static secondary ion mass spectroscopy (SIMS) analyses were also performed because of their higher surface sensitivity compared with XPS: ISS reveals that nitrogen is not present at the topmost surface layer of the treated samples but is incorporated just beneath. The outermost surface layer presents a composition rich in oxygen. Finally, static SIMS spectra show that corona treatment induces more surface degradation when performed in air compared with nitrogen or ammonia. These results are discussed in relation to adhesive properties of PET.