二甲基苯胺等离子体聚合及聚合物结构与性能的研究

应用外部电容耦合式等离子体聚合装置，研究了二甲基苯胺等离子体聚合规律，找到了最佳的聚合条件。通过热失重，红外光谱、Ｘ－射线衍射、电子衍射和接触角测定等，研究聚合物结构与性能。电导率测定表明二甲基苯胺等离子体聚合物具有半导体性质。     

醛类的等离子体聚合Ⅰ.丁醛等离子体聚合及聚合物结构与性能

应用外部电容耦合式等离子体聚合方法,首次得到了丁醛聚合物,研究了其聚合规律,找到了较好的聚合条件。通过元素分析和红外光谱分析,证实丁醛等离子体聚合物为交联结构;电子衍射分析和X-射线衍射分析发现聚合物中存在部分结晶,而且部分以单晶形式存在;表面能测定表明丁醛等离子体聚合物为疏水性。并初步探讨了反应机理。     

Low Pressure Radio Frequency Ammonia Plasma Surface Modification on Poly(ethylene terephthalate) Films and Fibers: Effect of the Polymer Forming Process

We investigated the effect of a polyethylene terephthalate (PET) forming process on radiofrequency ammonia plasma surface-treated PET flat films and fibres obtained by melt blowing. Ammonia plasma treatment allowed for the incorporation of amino functionalities on both the film and fibre surfaces, with higher values observed at very short treatment times. This plasma treatment also induced polymer chain scissions which were observed as the formation of hydrophilic nodules that coalesced together and were loosely bound to the underlying polymeric materials. These plasma-induced surface damages were notably more important on the melt-blown PET fibres. Consequently, maximisation of the surface amino groups with minimal polymer chain breaking was achieved using very short plasma treatment times (typically 1 s). We also demonstrated that the polymer forming process must be taken into account when plasma modifications are to be performed on PET, as it may already lead to polymer chain breakings subsequently added to those induced in the plasma environment.     

苯硫酚等离子体聚会及其结构与性能

应用外部电容耦合式等离子体聚合装置．研究了苯硫酚等离子体聚合规律，找到了最佳聚合条件，通过热失重、红外光谱、X－射线衍射、电子衍射、GC－MS和接触角测定等研究了聚合物结构与性能。电导率测定表明等离子体聚苯硫酚具有半导体性质。     

Distribution of polymer deposition in plasma polymerization. II. Effect of reactor design

The effects of relative positions of the monomer inlet and the r.f. coil, and of the inlet and outlet, on the distribution of polymer deposition in plasma polymerization of ethylene were investigated using an electrodeless glow discharge by a 13.5-MHz radiofrequency source. The diffusional transport of active species created under the r.f. coil, diffusional transport of polymer forming species, and flow of gas in the system are important factors that determine the distributions of polymer deposition observed in plasma polymerization of ethylene. The mechanisms of polymer deposition are discussed in conjunction with postulated plasma polymerization mechanisms.     

The synthesis and XPS characterization of iodine containing plasma polymers

Plasma polymers derived from iodobenzene and four copolymers with benzene of varying monomer ratios have been synthesized. Samples were analyzed for qualitative and quantitative information using x-ray photoelectron spectroscopy. The optimum conditions whereby a higher iodine content is obtained in the plasma polymer have been achieved. The results indicate that the use of a copolymerization approach is better. These plasma polymers were subsequently exposed to an oxygen plasma and it was found that oxidation and etching of the surfaces of the plasma polymers does occur. The extent of iodine loss via oxygen plasma etching appears dependent on the character of the plasma polymer.     

Effects of Monomer Flow Rate,Flow Configuration,and Reactor Geometry on the Rate of Plasma Polymerization

The effects of flow rate on the plasma polymerization of ethylene in an rf discharge were investigated using both a tubular and a bell-jar-type of reactor. Both reactors contained parallel plate internal electrodes. Experiments with the tubular reactor showed that both the total thickness of the deposit and its distribution in the axial direction were strong functions of the flow rate. At low flow rates the polymer thickness decreased in the flow direction, while at high flow rates the polymer thickness increased. Each of these observations is explained by a simple model of plasma polymerization. Using the bell-jar reactor, different monomer flow distribution configurations were tested to determine their effect on the distribution of polymer thickness. It was found that distribution or diffusion of the monomer inflow provided a more uniform film.     

Plasma for Modification of Polymers

The effect of nonpolymer-forming plasma (e.g., plasma of hydrogen, helium, argon, nitrogen) can be viewed as the following two reactions: 1) reaction of active species with polymer, and 2) formation of free radicals in polymer which is mainly due to the UV emitted by the plasma. The incorporation of nitrogen into the polymer surface by N₂ plasma and the surface oxidation by O₂ plasma are typical examples of the first effect. The latter effect generally leads to incorporation of oxygen in the form of carbonyl and hydroxyl and to some degree of cross-linking depending on the type of substrate; however, the degradation of polymer at the surface manifested by weight loss occurs in nearly all cases when polymers are exposed to plasma for a prolonged period of time. The effects of polymer-forming plasma is predominated by the deposition of polymer (plasma polymer); however, with some plasma-susceptible polymer substrates the effect of UV emission from polymer-forming plasma cannot be neglected. The mechanism of polymer formation can be explained by the stepwise reaction of active species and/or of an active specie with a molecule, and the chain addition polymerization of some organic compounds (e.g., vinyl monomers) is not the main route of polymer formation.

Plasma polymers contain appreciable amount of trapped free radicals; however, the concentration is highly dependent on the chemical structure of the monomer. In plasma polymerization, 1) triple bond and/or aromatic structure, 2) double bond and/or cyclic structure, and 3) saturated structure are three major functions which determine the rate of polymer formation and the properties of plasma polymers. The changes of some properties of plasma polymers with time are directly related to the concentration of trapped free radicals in plasma polymers. The amount of trapped free radicals in a plasma polymer is also influenced by the conditions of discharge; however, the UV irradiation from the polymer-forming plasma is not the main cause of these free radicals. Excess amount of free radicals are trapped during the process of polymer formation (rather than forming free radicals in the deposited polymer by UV irradiation). The properties of a plasma polymer is generally different from what one might expect from the chemical structure of the monomer, due to the fragmentation of atoms and/or functions during the polymerization process. This is another important factor to be considered for the modification of polymer surfaces by plasma polymerization.     

Surface Energy and Adhesive Properties of Polyamide 12 Modified by Barrier and Radio-Frequency Discharge Plasma

Summary. The polyamide 12 foil with sufficient surface and adhesive properties to other substrates can be prepared by discharge plasma modification. For improvement of bonding and printing of polymer a surface barrier discharge plasma in N₂ and O₂ as well as a radio-frequency discharge plasma in air has been studied. A significant increase in surface energy of the polymer as well as in strength of adhesive joint to more polar polymer was found. The chemical changes of PA 12 modified by plasma were analyzed using fourier transform infra red – attenuated total reflection (FTIR–ATR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) measurements. The observed changes of surface properties of the polymer due to aging were not important.     

Surface Energy and Adhesive Properties of Polyamide 12 Modified by Barrier and Radio-Frequency Discharge Plasma

The polyamide 12 foil with sufficient surface and adhesive properties to other substrates can be prepared by discharge plasma modification. For improvement of bonding and printing of polymer a surface barrier discharge plasma in N₂ and O₂ as well as a radio-frequency discharge plasma in air has been studied. A significant increase in surface energy of the polymer as well as in strength of adhesive joint to more polar polymer was found. The chemical changes of PA 12 modified by plasma were analyzed using fourier transform infra red – attenuated total reflection (FTIR–ATR) spectroscopy, and X-ray photoelectron spectroscopy (XPS) measurements. The observed changes of surface properties of the polymer due to aging were not important.     

Evaluation of the Effect of Plasma Treatment Frequency on the Activation of Polymer Particles

This study investigates the influence of treatment frequency (1–150 kHz) on the atmospheric plasma activation of both silicone and polyethylene terephthalate (PET) particles. These polymer particles with diameters in the range 3–5 mm, were treated using either helium or helium/oxygen gas mixtures, in a barrel atmospheric plasma system. The level of polymer particles activation was monitored using water contact angle measurements. The effect of plasma treatment frequency on barrel heating was monitored using an infrared thermographic camera, the maximum barrel temperature after 15 min treatment was found to be 98 °C at a frequency of 130 kHz. Optical emission spectroscopy was used as a diagnostic tool to monitor changes in atomic and molecular species spectral intensity with experimental conditions, as well as a change in electron energy distribution function. Electrical characterisation studies demonstrated an increase in plasma power with increasing frequency, in the range investigated. X-ray photoelectron spectroscopy analysis indicate an increase of oxygen content on polymer surfaces after plasma treatment. For silicone particles, the minimum polymer water contact angle was obtained by using a frequency of 130 kHz. After 15 min treatment time, the water contact angle decreased from 141° to 11°. While for PET particles the optimum treatment frequency was found to be 70 kHz, resulting in a water contact angle decreased from 94° to 32°. This lower frequency was used due to the partial melting of the PET (Tg of 80 °C), when treated at the higher frequency.     

Correlation between structure and stress-strain characteristics of metallic coatings deposited onto a polymer by the method of ionic plasma sputtering

Data on the strength of coatings based on noble metals (Pt, Au) deposited onto PET films by the method of ionic plasma sputtering are analyzed. In addition to precipitation of the metal, this mode of deposition is accompanied by modification of the surface polymer layer due to its interaction with plasma. As a result, a complex three-layered structure near the polymer surface forms. A new method for estimating the strength of coatings deposited onto polymer supports is advanced. This method makes it possible to analyze stress-strain characteristics of the three-layered systems that emerge owing to deposition of nanoscale layers of noble metals on polymer films via ionic plasma sputtering. The proposed relationships are in fair agreement with the experimental data.     

Contributions of restructuring and oxidation to the aging of the surface of plasma polymers containing heteroatoms

The properties and composition of plasma polymer surfaces stored in air can change considerably over time, especially as a result of oxidative reactions. When plasma polymers contain an element other than O, it is possible to probe for mechanisms in addition to oxidation that contribute to the aging of the surface. Plasma polymers containing N were fabricated from either 1,3-diaminopropane (DAP),n-heptylamine (nHA), or allylamine (AA), and studied by X-ray photo-electron spectroscopy (XPS) and air/water contact angles (CA). For each of the plasma polymers, a multiexponential increase in the O/C ratio was observed over time using XPS. The N/C ratios remained constant (AA) or decreased somewhat (nHA and DAP). In contrast, the trends in CA values differed, declining for the nHA surfaces, rising for the AA, and changing little for the DAP. Surface roughness, assessed by scanning tunnelling or atomic force microscopy, did not change over time. The diverse adjustments in the polarity of each surface and the similar compositional changes between them are reconcilable if the aging of the plasma polymer surface is a manifestation of the superposition of concurrent oxidative reactions and partial surface reorientation; the former introduce polar groups and the latter transports then from the surface to deeper regions beyond the CA probe depth but within the XPS analysis depth. These processes vary between different plasma polymers. Data for the alkylamine plasma polymers is also compared with that for two plasma polymers fabricated from methanol. The change in composition, but not polarity, of the DAP surface after 4 days of storage demonstrates the importance of using multiple techniques to characterize the aging of plasma polymer surfaces.     

The competitive ablation and polymerization (CAP) principle and the plasma sensitivity of elements in plasma polymerization and treatment

The competitive ablation and polymerization (CAP) principle relates the ablation of materials in plasma to the deposition of materials in plasma. Plasma polymerization and plasma treatment cannot be elucidated without consideration of the fragmentation of molecules in both the gas and solid phases. The general fragmentation tendency follows a plasma sensitivity series of the elements involved that is based on element electronegativity. When consecutive plasma treatments, sequential plasma polymerization, or a combination of plasma treatment and plasma polymerization are carried out in the same reactor, factors that are often not considered in an ordinary individual process become crucial. The CAP principle and the concept of a plasma sensitivity series of the elements explain the rather complicated and interrelated influences of fragmented elements in the plasma deposition of materials. Plasma polymers should be considered a mixture of oligomers and polymeric networks. The oligomer content in a plasma‐polymerized layer is vitally important to the adhesion of the plasma polymer to the substrate as well as to any subsequent coating applied to the layer of the plasma polymer. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 943–953, 2000     

Amphipathic and membrane-destabilizing properties of the cationic acrylate polymer Eudragit E100

The cationic acrylate polymer Eudragit E100 (E100) produces a biphasic effect on the stability of casein micelles disrupting their internal structure. These results suggested that this polymer could have some amphipathic character. Therefore, in this study the polymer was characterized with respect to its interaction with different amphipathic systems (bile-acid micelles, lipoproteins and liposomes), cell membranes (red blood cells) and virus membranes (Herpes simplex type 2 virus). As with caseins, a biphasic effect was observed with bile acids with a precipitation phase at low polymer/bile acid ratio and a solubilization phase when the polymer concentration was increased. Upon interaction with human plasma, an important reduction in cholesterol and triglycerides was observed upon remotion of E100 by a rise in pH to 8.5 and centrifugation. In agreement with this finding, an important reduction in plasma lipoproteins was observed upon its treatment with E100 and further remotion by pH rise and centrifugation. However, the amount of the major protein components of human plasma and the activity of several enzymes and antibodies were not affected by their treatment with E100. The membrane-destabilizing properties of E100 were confirmed by its lytic activity on liposomes and red blood cells and by an important antiviral effect of E100 on Herpes simplex virus type 2. Altogether, these results show that, despite its water solubility and cationic character, E100 displays a significative amphipathic and membrane-destabilizing character with potential biotechnological applications. [diagram in text].     

等离子体聚合和处理在聚合物改性中的应用

本文综述了等离子聚合和处理在聚合物改性中的应用，介绍并述评了其发展概况。并对高分子等离子体化学在分离膜、保护膜、电子材料、光学材料等领域中的最新应用进行了介绍。     

Mechanism of the Immobilization of Surfactants on Polymer Surfaces by Means of an Argon Plasma Treatment: Influence of UV Radiation

The mechanism of the immobilization of the surfactant sodium 10-undecenoate (C11(:)) on poly(ethylene) (PE) by means of an argon plasma treatment has been investigated. In particular, the influence of the vacuum ultraviolet (UV) radiation emitted by the argon plasma on the immobilization was studied. For this purpose, PE samples were coated with C11(:) (PE/C11(:) samples) and treated with an argon plasma under different conditions. PE/C11(:) samples were placed inside (glow) and outside (afterglow) the visible region of the plasma. Additionally, polymer samples that were placed in the glow of the plasma were covered with lithium fluoride or quartz crystals. These materials are transparent for electromagnetic radiation with a wavelength longer than 104 and 150 nm, respectively. Derivatization X-ray Photoelectron Spectroscopy was applied to characterize the modified polymer surfaces. It was demonstrated that vacuum UV radiation with a wavelength shorter than 150 nm made a predominant contribution to the process of immobilization. Under certain conditions it was possible to retain about 30% of the functional groups of the initially coated surfactant layer on PE. Furthermore, the UV radiation accounted for etching of PE and PE/C11(:) surfaces and initiated oxidation of the polymer surfaces.     

TEM-cross section investigations of plasma polymer silver composite films

Plasma polymer silver composite films were investigated by means of cross section transmission electron microscopy (XTEM). The silver is encapsulated in the form of small particles in a nearly homogeneous plasma polymer matrix. The shape and the size of the particles vary with the polymerization power density. At lower polymerization power density the silver particles appear almost spherical and a three-dimensional particle distribution can be found in the polymer matrix. However the shape of particles at higher power density is more elliptic and the particle distribution is two-dimensional. The different kinds of encapsulation can be interpreted as being due to the different densities and porosities of the plasma polymer matrix.     

Some aspects of plasma polymerization investigated by pulsed R.F. discharge

The polymerization of organic compounds in glow discharge (plasma polymerization) was investigated by using pulsed R.F. discharge (100 μsec on, 900 μsec off). The effects of pulsed discharge on polymer deposition rate, pressure change in plasma, ESR signals of free spins in both plasma polymer and substrate, and the contact angle of water on the plasma polymer surface were investigated for various organic compounds. The results are correlated to the mechanisms of polymer formation in plasma (plasma polymerization) which has been postulated as repeating processes of stepwise (propagation) reactions. The effect of the pulse is different from one group of organic compounds to another depending on whether or not they contain an olefinic double bond and/or a triple bond. The main difference seems to be the addition polymerization which can occur exclusively during the off-period of pulsed discharge. Ultraviolet emission from pulsed discharge is much less than from continuous discharge. Consequently, the fragmentation of the monomer and the free-radical formation in the substrate are less with the pulsed discharge. Properties of polymers from some organic compounds formed in continuous and in pulsed discharge were found to be significantly different, and the differences were postulated from the changes of polymerization mechanisms in the pulsed discharge.     

等离子体引发丙烯酰胺水溶液聚合

用两种等离子体引发丙烯酰胺水溶液聚合的方法 ,制备了线性超高分子量聚丙烯酰胺 .研究了放电时间、放电功率、单体的初始浓度及溶液的pH值等对聚合产物的影响